On Tuesday, 26 April 2016 10:05:49 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:14:27 +0100, dennis@home wrote:

On 26/04/2016 00:21, Mr Macaw wrote:

Simple experiment. A hula hoop around your head, with a coloured bead
slid slowly round it, while you stare straight ahead. You shout out the
colour when you see it.

That would be a couple of degrees then as rods don't detect colour only
cones do that and they are in the centre of your field of view.
Any colour you see in the peripheral field is just made up by your brain.

Funny how my eyesight and everyone in the class worked with colour round there. The only thing you don't pick up colour with is very low light levels.

you'll have to define seeing and looking.
See if you can read a newspaper out of the corner of yuor eye if you can;t yuo're not really seeing are you.

On Tue, 26 Apr 2016 12:18:26 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 10:05:49 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:14:27 +0100, dennis@home wrote:

On 26/04/2016 00:21, Mr Macaw wrote:

Simple experiment. A hula hoop around your head, with a coloured bead
slid slowly round it, while you stare straight ahead. You shout out the
colour when you see it.

That would be a couple of degrees then as rods don't detect colour only
cones do that and they are in the centre of your field of view.
Any colour you see in the peripheral field is just made up by your brain.

Funny how my eyesight and everyone in the class worked with colour round there. The only thing you don't pick up colour with is very low light levels.

you'll have to define seeing and looking.
See if you can read a newspaper out of the corner of yuor eye if you can;t yuo're not really seeing are you.

I'm talking about noticing something out of the corner of my eye. In my OP it was about my cat spotting me walking towards it. He doesn't have to read the logo on my clothes.

--
If you walk into a nuclear power station with a pocket full of Brazil nuts, you will set off the radiation leak alarm, as Brazil nuts are radioative.

On Tue, 26 Apr 2016 12:15:17 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 10:07:37 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:55:10 +0100, Tim Lamb wrote:


I like to claim good peripheral vision but 200deg. is only *something
there* or movement.

Not with me, I just held up a variety of bottles of pop at just past right angles and could tell which colour was which (I picked them up randomly from behind my back so my brain couldn't "cheat").

You can't really test yourself that's the point.

Yes you can and I just explained how.

I have to wonder where these "studies" get their bull**** from. I simply can't believe I have cones where others don't.

you don't all your' doing is moving yuor eye without realising.

I know if I move my eye, I'm not retarded.

It's similar to saying boo to yourself and wondering why you didnlt jump like other sdo. it doesnt; make you special.
Tickling yourself is another thing you can't do effectively.

Those are entirely different things.

Although does anyone know why tickling doesn't work? Boo is obvious, it's not a fright if you know it's going to happen. Won't work if your friend says "I'm about to say boo, BOO!!" either.

--
Beating your wife is like keying your own car.

On Tue, 26 Apr 2016 11:49:58 +0100, tony sayer wrote:

In article , NY
scribeth thus
"Mr Macaw" wrote in message news
"The visual field of the human eye spans approximately 120 degrees of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

Wikipedia contradicts itself in another article:

No, the difference is whether you are talking about one or two eyes.

No, with one eye it says 100-110 degrees outwards and 60 degrees towards
the nose. That makes 160-170 degrees.

Anyway, we were discussing sight, not sight with one eye shut. We were
discussing how far round you can see an object when looking straight
ahead.

I presume "when looking straight ahead" means without swivelling your eyes.
Maybe there should be two sets of figures with/without swivelling, because
when you detect something on the periphery, you look towards it (by
swivelling the eyes) and then see a bit further round in that direction.

200 degrees sounds incredibly high, but I've never tested my field of view.
I would have guessed that it would be slightly under 180 degrees - but that
it a guess without any testing. Maybe it *is* a realistic figure...


It is oddly enough a good test to see if your pituitary gland isn't
playing up as this swelling, with a tumour of the same name, can affect
the peripheral vision as it presses on the Optic nerve.

My neighbour had a stroke and got tunnel vision (up to 3 months of it according to the doctor).

Guess who's got one of they;!(

Usual method is to stare at a fixed point in front of you then with your
arms outstretched at the same level as your eye and with your thumb up
wiggle that from side to side and move it around towards the back of
your head it usually is around 108 deg in total the field.

Bring it back and as soon as you notice the movement of your thumb
whilst staring straight ahead that is the angle at that point..

--
Einstein married his cousin, Elsa Lowenthal, after his first marriage failed in 1919.
At the time he stated that he was attracted to Elsa "because she was so well endowed".
He postulated that if you are attracted to women with large breasts, the attraction is even stronger if there is a DNA connection.
This came to be known as.... Einstein's Theory of "Relative Titty."

On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of vision than men have. I believe this helps them nags us from any direct.

Are you sure that isn't a myth like them being able to see more colours?

I disagree with this. Firstly, I tested my own vision and I have 220 degrees.

It's difficult to test yourself, have you ever tried tickling yourself ?.

Those are not comparable.

The human eye only looks at about 15% of it's view it sort of scans and reports back to the brain.

You can tell if you're scanning and cheating.

Cats are better at seeing changes or fast movemnt rather than gradual changes which they dont normally worry about.

That cat always worries about me.

Secondly, I always find my cats looking straight at me or whatever they want to examine,

same for most creatures, as the cnetre of the eye is usually the the best for general viewing.

Yes, but you don't stare directly at a person for more than a second or two. It doesn't take long to gather the details you need.

Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

they don't seem to be able to see sideways, and the other day I walked over to one cat, I was 90 degrees from his forward direction, and he didn't see me until I touched him to stroke him, which scared the hell out of him.

Maybe he was day dreaming.

He was licking his leg.

What are your experiences of cats vision (and your own)?

Sometimes it sees a small fly or perhaps it hears it but it's following something I just can't see myself.
Cat was on my lap the other night and sudeetnly she started staring strangly at the window I tought it was something on the TV, but no it was a bird on the TV areal across the road through the net curtains, maybe some refelction or something made her suddently look up, but all I could see was a bird on a TV areail which didn;t hold my inerest but held hers for nearly 2 mins then she went back to sleep.

It's a simple life.

--
A teacher wanted to teach her students about self-esteem, so she asked anyone who thought they were stupid to stand up. One kid stood up and the teacher was surprised. She didnt think anyone would stand up so she asked him, €œWhy did you stand up?€� He answered, €œI didnt want to leave you standing up by yourself.€�

On Tue, 26 Apr 2016 02:53:54 +0100, Rod Speed wrote:

Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote

http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as
compared to 180 degrees in humans"

I disagree with this. Firstly, I tested my own vision and I have
220 degrees.

Yeah, mine is much wider than most peoples' too.

You mean my 220 degrees is odd?

Just that its unusual for humans.

I seem to remember my classmates when I was at school were all quite
similar.

Either you stuffed that measurement up

Simple experiment.

Yes, but you must have either stuffed that up or have
fluked a very unusual group if everyone had the same
peripheral vision or you are remembering that wrong.

Not the same, all 180 degrees and over.

A hula hoop around your head, with a coloured bead slid slowly round it,
while you stare straight ahead. You shout out the colour when you see it.

or you're remembering it wrong.

I wouldn't forget that it was just over right angles.

That one is just a different measure, one eye or both eyes.

Most people don't have one eye closed.

No wonder people don't see people coming when they drive.

You dont need 220 degrees to do that.

You dont even need 180 degrees.

If you don't have 180 degrees, you have to turn your head or move your
eyes all the time.

Most do that when coming up to an intersection.

I do too.

Yes, but peripheral vision means you see things you weren't looking for.

Yes, but most do look for oncoming cars.

And accidents are often caused because someone fails to look in one particular direction (hence "he came out of nowhere"). Good peripheral vision means you'd still see them.

With 220 degrees, you see people to the side of your that you aren't
looking for, and you can effectively look both ways at once at a
junction.

I dont know anyone who doesnt move their head or their
eyes when coming up to an intersection, including me.

Because you get better vision with the central part.

Yes.

Peripheral vision will tell you something is moving, but probably not how
fast and what direction.

And wont necessarily distinguish between say
a bike and a small tree or something like that
which will be moving in your field of vision
just because your car is moving as you drive up.

Then you must be able to tell direction of movement out of the corner of your eyes, because I don't notice a tree moving because of my movement, my brain ignores it. But a car moving alerts me to look that way.

The glassblower at work would always know
when you talked up behind them, but that
was because of your reflection in their glasses.

I've had someone make rude gestures at me when I'm stood at a front door waiting for an answer. A glass front door. Then they're surprised when I notice them.

Secondly, I always find my cats looking straight at me or whatever
they want to examine, they don't seem to be able to see sideways,

That's a different question. I look directly at what
I want to focus on, but that doesnt mean that I
dont notice movement out of the corner of my eyes.

But I don't find myself staring continuously at the cat.

That may just be an evolutionary thing, works
better when catching rodents and insects etc.

It wasn't trying to eat me.

Sure, but that evolutionary behaviour may well apply to
anything it is concentrating on, not just what its about to
eat. You get the same thing with laser pointers or even
with something inedible on the end of a bit of string etc.

One of my cats does it forever. The rest will look away if I stare back
for more than 5 seconds.

That's because of your rabid blood shot eyes and the flecks of
foam about the lips and you howling at the top of your voice.
They are deciding whether to run or just hope for the best.

No, they're trying to work out if I'm angry at them for what they just did. Although I've taught them not to do most of their bad habits now, so they are no longer so wary.

Once I've examined it, I don't need to keep watching it if it's not
doing anything.

These cats dont do that.
https://www.youtube.com/watch?v=KIeP...ature=youtu.be

They're either staring at each other or the camera.

They are looking at more than just those two things.

I only flipped through it quickly, but I only saw two things.

and the other day I walked over to one cat, I was 90 degrees from
his forward direction, and he didn't see me until I touched him to
stroke him, which scared the hell out of him.

Yeah, that's a much better test of that field of vision question..

Bur its likely that some cats have a form of tunnel
vision too. We know that young kids to, that's why
they can get run over when crossing the road.

I don't believe you.

Doesnt matter what you believe, that's been established
with rigorous science for a long time now. Trivial to test.

Utter bull****.

Fact.

"Newborn babies have peripheral vision" -
http://www.aao.org/eye-health/tips-p...on-development

Irrelevant to whether younger kids have a narrower field of view than
when they get older.

"Overall there was little evidence to support the hypothesis that
children
have poorer peripheral vision than adults relative to their foveal
vision." - http://www.ncbi.nlm.nih.gov/pubmed/3801789

Pity about the other studys that show they do have.

"Generally, if a baby

We aren't talking about babys.

is not tracking motion across their full range of vision by 3 months of
age, parents should consult their pediatrician."

That has nothing to do with why kids get run over.

-
http://everydaylife.globalpost.com/p...rs-44127..html

Basically kids that don't use their peripheral vision are just plain
stupid. Their eyes work as well as ours.

Wrong with peripheral vision.

From personal experience of myself and school chums, it's the same in kids
as adults.

That's nothing like a rigorous scientific measurement
of peripheral vision in kids and adults. That's been done.

Yet all these "scientific measurements" never seem to agree. Like the global warming bull****.

And the links I read show it's more a lack on concentration than sight.

On Tuesday, 26 April 2016 13:52:22 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:15:17 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 10:07:37 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:55:10 +0100, Tim Lamb wrote:


I like to claim good peripheral vision but 200deg. is only *something
there* or movement.

Not with me, I just held up a variety of bottles of pop at just past right angles and could tell which colour was which (I picked them up randomly from behind my back so my brain couldn't "cheat").

You can't really test yourself that's the point.

Yes you can and I just explained how.

But not exactly acurratly.
Now when you tested your cat your cat didn't know you were testing it.
when you tested your eyes you knew you were running a teat so were ready
and primed even if unintentianlly.

There;s an episode of ducks quakes don;t echo where they tried this out
on drivers findign that women drivers have better peripheral vision than me.
But one thing you don;t do when testing anything is to tell the subject what's being tested.

Go on try the other senses on yourself.
Stamnd in a dark room and sometime in 5mins shout boo see if you can
make yourself jump, then get someone else to say boo see if that works.

They did a similar thing with tickling too.




I have to wonder where these "studies" get their bull**** from. I simply can't believe I have cones where others don't.

you don't all your' doing is moving yuor eye without realising.

I know if I move my eye, I'm not retarded.

yuo wopn;t know as the brain doesn;t record such things, it's like blinking it just happens, of can yuo tell me how many tiomes you've blinked in teh last 5 mins and did you notice yourself blinking.
It's also similar to breathing in that it's not concious during the event.



Although does anyone know why tickling doesn't work?

yes again done on duck qusacks don;t echo it';s yuo brain perciving movement.
you can not be ticlkish by placing your hand on teh persons hand that is ticlking you, that way you know the location of their hand so the 'tickle' is no longer a suprise event.

On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of vision than men have. I believe this helps them nags us from any direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be colour blind.
This all goes back to our early ancestors in men they had to be quick to hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and scattter cushions while the men are hunting pints.


It's difficult to test yourself, have you ever tried tickling yourself ?.

Those are not comparable.

The human eye only looks at about 15% of it's view it sort of scans and reports back to the brain.

But similar ideas.




Cats are better at seeing changes or fast movemnt rather than gradual changes which they dont normally worry about.

That cat always worries about me.

So is used to you.



Secondly, I always find my cats looking straight at me or whatever they want to examine,

same for most creatures, as the cnetre of the eye is usually the the best for general viewing.

Yes, but you don't stare directly at a person for more than a second or two. It doesn't take long to gather the details you need.


So cats don;t like diorect eye contact for very long as in teh animal kingdon it's a threat, but in humans it doesn;t work like that, cats reaslise this.


Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.



they don't seem to be able to see sideways, and the other day I walked over to one cat, I was 90 degrees from his forward direction, and he didn't see me until I touched him to stroke him, which scared the hell out of him.

Maybe he was day dreaming.

He was licking his leg.

So explains it.
How can you can an accurate ID of the angle of a cats vision while it;s washing it's leg.



What are your experiences of cats vision (and your own)?

Sometimes it sees a small fly or perhaps it hears it but it's following something I just can't see myself.
Cat was on my lap the other night and sudeetnly she started staring strangly at the window I tought it was something on the TV, but no it was a bird on the TV areal across the road through the net curtains, maybe some refelction or something made her suddently look up, but all I could see was a bird on a TV areail which didn;t hold my inerest but held hers for nearly 2 mins then she went back to sleep.

It's a simple life.

distrubed by something I didn't notice happening on a roof across the road.

On Tue, 26 Apr 2016 16:50:33 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of vision than men have. I believe this helps them nags us from any direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be colour blind.
This all goes back to our early ancestors in men they had to be quick to hunt women has to recognise cours for differmnt type of fruit and veg..
WHich is also why generally omen are bettere at picking out curtains and scattter cushions while the men are hunting pints.

No it's not all women, just some. And I don't see how four cones helps anyway. What's the point in having one inbetween two others? You can sense any colour between those two receptors by the brain analysing the strength of the signal from each receptor. Which is why we don't see three colours, but an infinite number.

https://en.wikipedia.org/wiki/Tetrachromacy

"In humans, two cone cell pigment genes are present on the X chromosome: the classical type 2 opsin genes OPN1MW and OPN1MW2. It has been suggested that humans with two X chromosomes could possess multiple cone cell pigments, perhaps born as full tetrachromats who have four simultaneously functioning kinds of cone cells, each type with a specific pattern of responsiveness to different wavelengths of light in the range of the visible spectrum.[16] One study suggested that 2€“3% of the world's women might have the type of fourth cone whose sensitivity peak is between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.[17] Another study suggests that as many as 50% of women and 8% of men may have four photopigments and corresponding increased chromatic discrimination compared to trichromats.[16] In 2010, after 20 years of study of women with four types of cones (non-functional tetrachromats), neuroscientist Dr. Gabriele Jordan
identified a woman (subject cDa29) who could detect a greater variety of colors than trichromats could, corresponding with a functional tetrachromat (or true tetrachromat).[18][19] Apes, Old World monkeys, and Humans normally have three types of cone cells and are therefore trichromats. However, at low light intensities, the rod cells may contribute to color vision, giving a small region of tetrachromacy in the color space;[20] human rod cells' sensitivity is greatest at a blueish-green wavelength."

It's difficult to test yourself, have you ever tried tickling yourself ?.

Those are not comparable.

But similar ideas.

What makes you think you can't test yourself? You know the way you're looking, and you know where the thing is you're trying to see.

Tickling, **** knows, that doesn't make sense.

Cats are better at seeing changes or fast movemnt rather than gradual changes which they dont normally worry about.

That cat always worries about me.

So is used to you.

And should have run away as I approached. Even if it wasn't scared of me, it should have noticed I was reaching over to stroke him, and not jump out of his skin when I touched him.

Secondly, I always find my cats looking straight at me or whatever they want to examine,

same for most creatures, as the cnetre of the eye is usually the the best for general viewing.

Yes, but you don't stare directly at a person for more than a second or two. It doesn't take long to gather the details you need.

So cats don;t like diorect eye contact for very long as in teh animal kingdon it's a threat, but in humans it doesn;t work like that, cats reaslise this.

They must then also realise it's considered annoying.

Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

Nope, google for it and find thousands of people complaining about it.

they don't seem to be able to see sideways, and the other day I walked over to one cat, I was 90 degrees from his forward direction, and he didn't see me until I touched him to stroke him, which scared the hell out of him.

Maybe he was day dreaming.

He was licking his leg.

So explains it.
How can you can an accurate ID of the angle of a cats vision while it;s washing it's leg.

Can it not observe something approaching it while it's washing? So you not notice someone walking towards you when you're washing the dishes?

What are your experiences of cats vision (and your own)?

Sometimes it sees a small fly or perhaps it hears it but it's following something I just can't see myself.
Cat was on my lap the other night and sudeetnly she started staring strangly at the window I tought it was something on the TV, but no it was a bird on the TV areal across the road through the net curtains, maybe some refelction or something made her suddently look up, but all I could see was a bird on a TV areail which didn;t hold my inerest but held hers for nearly 2 mins then she went back to sleep.

It's a simple life.

distrubed by something I didn't notice happening on a roof across the road.

I meant for cats in general.

--
NEWSFLASH!!! Bouncing elephantiasis woman destroys central Portsmouth

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 11:22:07 +0100, NY wrote:

"Mr Macaw" wrote in message
news
"The visual field of the human eye spans approximately 120 degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

Wikipedia contradicts itself in another article:

No, the difference is whether you are talking about one or two eyes.

No, with one eye it says 100-110 degrees outwards and 60 degrees towards
the nose. That makes 160-170 degrees.

Anyway, we were discussing sight, not sight with one eye shut. We were
discussing how far round you can see an object when looking straight
ahead.

I presume "when looking straight ahead" means without swivelling your
eyes.
Maybe there should be two sets of figures with/without swivelling,
because
when you detect something on the periphery, you look towards it (by
swivelling the eyes) and then see a bit further round in that direction.

200 degrees sounds incredibly high, but I've never tested my field of
view.
I would have guessed that it would be slightly under 180 degrees - but
that
it a guess without any testing. Maybe it *is* a realistic figure...

Easy enough to test yourself. I can see past right angles. I guess some
people are more or less than others, but I wouldn't think by much.

Now what probably varies considerably is people's 3D field of view - if
you have a large bridge on your nose, it will obstruct the view from one
of your eyes.

Perhaps this is why people with cute little noses do better in a lot of
sports.

What is the evidence that they do ? Can you list some example of
individuals like that ?

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 10:43:13 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news
On Tue, 26 Apr 2016 02:36:32 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news On Mon, 25 Apr 2016 23:00:22 +0100, Rod Speed

wrote:

Harry Bloomfield wrote
michael adams wrote

Meanwhile, back in the real world...

"The visual field of the human eye spans approximately 120 degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

That is one of the more superficial wikipedia articles.

My own test on myself, suggests mine is much wider than that close
to
200
degrees. Raise a finger of each hand concentrate on the PC screen,
move
the hands back at either side of the head, until the fingers
disappear
from view - 200 degrees.

Yeah, mine is something like that too. Much more than 120.

I don't believe anyone has 120 who doesn't have a severe eye defect.

Looks like we are using different measures, one and two eyes.
https://en.wikipedia.org/wiki/Peripheral_vision

One eye is irrelevant to the topic in hand - how far to your right can
you
see when staring straight ahead.

Yes, but it makes a big difference to the total you say.

My point is why was anyone looking up single eyes?

No one who matters is but the field of vision does get
stated both ways so you need to be clear which way
you are stating when you say what field of view you have.

You see things on your left with one eye and things on your right with the
other. The field of vision of only one eye is useless information.

But some do state the field of view that way.

Both Wikipedia articles say it's just past right angles.

Which isnt all that different to the 200 Harry said he has.

I can believe 180, 200, 220, but I find it hard to believe many people are
much below 180.

Quite a few primary school aged kids do.

On Tue, 26 Apr 2016 19:39:29 +0100, Rod Speed wrote:



"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 10:43:13 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news On Tue, 26 Apr 2016 02:36:32 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news On Mon, 25 Apr 2016 23:00:22 +0100, Rod Speed

wrote:

Harry Bloomfield wrote
michael adams wrote

Meanwhile, back in the real world...

"The visual field of the human eye spans approximately 120 degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

That is one of the more superficial wikipedia articles.

My own test on myself, suggests mine is much wider than that close
to
200
degrees. Raise a finger of each hand concentrate on the PC screen,
move
the hands back at either side of the head, until the fingers
disappear
from view - 200 degrees.

Yeah, mine is something like that too. Much more than 120.

I don't believe anyone has 120 who doesn't have a severe eye defect.

Looks like we are using different measures, one and two eyes.
https://en.wikipedia.org/wiki/Peripheral_vision

One eye is irrelevant to the topic in hand - how far to your right can
you
see when staring straight ahead.

Yes, but it makes a big difference to the total you say.

My point is why was anyone looking up single eyes?

No one who matters is but the field of vision does get
stated both ways so you need to be clear which way
you are stating when you say what field of view you have.

Two eyes is the only sensible thing to look at in this context. You'd only talk about one eye if you were a doctor trying to figure out what's wrong with it.

You see things on your left with one eye and things on your right with the
other. The field of vision of only one eye is useless information.

But some do state the field of view that way.

Both Wikipedia articles say it's just past right angles.

Which isnt all that different to the 200 Harry said he has.

I can believe 180, 200, 220, but I find it hard to believe many people are
much below 180.

Quite a few primary school aged kids do.

My schoolchums weren't.

--
Today's woman puts on wigs, fake eyelashes, false fingernails, sixteen pounds of assorted make-up/shadows/blushes/creams, living bras, various pads that would make a linebacker envious, has implants and assorted other surgeries, then complains that she cannot find a "real" man.

On Tue, 26 Apr 2016 19:36:20 +0100, Rod Speed wrote:



"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 11:22:07 +0100, NY wrote:

"Mr Macaw" wrote in message
news "The visual field of the human eye spans approximately 120 degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

Wikipedia contradicts itself in another article:

No, the difference is whether you are talking about one or two eyes.

No, with one eye it says 100-110 degrees outwards and 60 degrees towards
the nose. That makes 160-170 degrees.

Anyway, we were discussing sight, not sight with one eye shut. We were
discussing how far round you can see an object when looking straight
ahead.

I presume "when looking straight ahead" means without swivelling your
eyes.
Maybe there should be two sets of figures with/without swivelling,
because
when you detect something on the periphery, you look towards it (by
swivelling the eyes) and then see a bit further round in that direction.

200 degrees sounds incredibly high, but I've never tested my field of
view.
I would have guessed that it would be slightly under 180 degrees - but
that
it a guess without any testing. Maybe it *is* a realistic figure...

Easy enough to test yourself. I can see past right angles. I guess some
people are more or less than others, but I wouldn't think by much.

Now what probably varies considerably is people's 3D field of view - if
you have a large bridge on your nose, it will obstruct the view from one
of your eyes.

Perhaps this is why people with cute little noses do better in a lot of
sports.

What is the evidence that they do ?

It's a good theory. It's a sign they have better made bodies, and it also means both eyes can see further.

Can you list some example of individuals like that ?

Jessica Ennis.

--
Bad or missing mouse. Spank the cat [Y/N]?

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 02:53:54 +0100, Rod Speed
wrote:

Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote
Rod Speed wrote
Mr Macaw wrote

http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as
compared to 180 degrees in humans"

I disagree with this. Firstly, I tested my own vision and I have
220 degrees.

Yeah, mine is much wider than most peoples' too.

You mean my 220 degrees is odd?

Just that its unusual for humans.

I seem to remember my classmates when I was at school were all quite
similar.

Either you stuffed that measurement up

Simple experiment.

Yes, but you must have either stuffed that up or have
fluked a very unusual group if everyone had the same
peripheral vision or you are remembering that wrong.

Not the same, all 180 degrees and over.

You previously said they were all quite similar.

A hula hoop around your head, with a coloured bead slid slowly round it,
while you stare straight ahead. You shout out the colour when you see
it.

or you're remembering it wrong.

I wouldn't forget that it was just over right angles.

That one is just a different measure, one eye or both eyes.

Most people don't have one eye closed.

No one said they did.

No wonder people don't see people coming when they drive.

You dont need 220 degrees to do that.

You dont even need 180 degrees.

If you don't have 180 degrees, you have to turn your head or move your
eyes all the time.

Most do that when coming up to an intersection.

I do too.

Yes, but peripheral vision means you see things you weren't looking for.

Yes, but most do look for oncoming cars.

And accidents are often caused because someone fails to look in one
particular direction (hence "he came out of nowhere"). Good peripheral
vision means you'd still see them.

And when accidents like that are quite common, particularly
when its a motorbike or a person riding a push bike, clearly
good peripheral vision isnt as common as you claim.

With 220 degrees, you see people to the side of your that you aren't
looking for, and you can effectively look both ways at once at a
junction.

I dont know anyone who doesnt move their head or their
eyes when coming up to an intersection, including me.

Because you get better vision with the central part.

Yes.

Peripheral vision will tell you something is moving, but probably not
how
fast and what direction.

And wont necessarily distinguish between say
a bike and a small tree or something like that
which will be moving in your field of vision
just because your car is moving as you drive up.

Then you must be able to tell direction of movement out of the corner of
your eyes, because I don't notice a tree moving because of my movement, my
brain ignores it. But a car moving alerts me to look that way.

Must be why so many motorbikes and
bike riders get runover in that situation.

The glassblowers at work would always know
when you talked up behind them, but that
was because of your reflection in their glasses.

I've had someone make rude gestures at me when I'm stood at a front door
waiting for an answer. A glass front door. Then they're surprised when I
notice them.

Never had that myself.

Secondly, I always find my cats looking straight at me or whatever
they want to examine, they don't seem to be able to see sideways,

That's a different question. I look directly at what
I want to focus on, but that doesnt mean that I
dont notice movement out of the corner of my eyes.

But I don't find myself staring continuously at the cat.

That may just be an evolutionary thing, works
better when catching rodents and insects etc.

It wasn't trying to eat me.

Sure, but that evolutionary behaviour may well apply to
anything it is concentrating on, not just what its about to
eat. You get the same thing with laser pointers or even
with something inedible on the end of a bit of string etc.

One of my cats does it forever. The rest will look away if I stare back
for more than 5 seconds.

That's because of your rabid blood shot eyes and the flecks of
foam about the lips and you howling at the top of your voice.
They are deciding whether to run or just hope for the best.

No, they're trying to work out if I'm angry at them for what they just
did.

That's because you keep kicking them.

Although I've taught them not to do most of their bad habits now, so they
are no longer so wary.

Once I've examined it, I don't need to keep watching it if it's not
doing anything.

These cats dont do that.
https://www.youtube.com/watch?v=KIeP...ature=youtu.be

They're either staring at each other or the camera.

They are looking at more than just those two things.

I only flipped through it quickly, but I only saw two things.

and the other day I walked over to one cat, I was 90 degrees from
his forward direction, and he didn't see me until I touched him to
stroke him, which scared the hell out of him.

Yeah, that's a much better test of that field of vision question.

Bur its likely that some cats have a form of tunnel
vision too. We know that young kids to, that's why
they can get run over when crossing the road.

I don't believe you.

Doesnt matter what you believe, that's been established
with rigorous science for a long time now. Trivial to test.

Utter bull****.

Fact.

"Newborn babies have peripheral vision" -
http://www.aao.org/eye-health/tips-p...on-development

Irrelevant to whether younger kids have a narrower field of view than
when they get older.

"Overall there was little evidence to support the hypothesis that
children
have poorer peripheral vision than adults relative to their foveal
vision." - http://www.ncbi.nlm.nih.gov/pubmed/3801789

Pity about the other studys that show they do have.

"Generally, if a baby

We aren't talking about babys.

is not tracking motion across their full range of vision by 3 months
of
age, parents should consult their pediatrician."

That has nothing to do with why kids get run over.

-
http://everydaylife.globalpost.com/p...ers-44127.html

Basically kids that don't use their peripheral vision are just plain
stupid. Their eyes work as well as ours.

Wrong with peripheral vision.

From personal experience of myself and school chums, it's the same in
kids
as adults.

That's nothing like a rigorous scientific measurement
of peripheral vision in kids and adults. That's been done.

Yet all these "scientific measurements" never seem to agree.

They do with simple stuff like that.

Like the global warming bull****.

Nothing like. That one can't even be done using experiments,
only observation is possible and its very hard to observe
accurately with global temperatures too.

And the links I read show it's more a lack on concentration than sight.

Easy to test that possibility.

Not really.

Yes, really. You do your test or the finger wiggling
version of it with and without other distractions.

"Why did you cross the road when a car was coming?" "I didn't notice it."
"Why? Didn't you see it or were you too busy chatting to your friend?"
"I don't know. I just didn't know the car was there."

That's not an experiment, that's just asking the kid after the event.

They have the same vision, they just don't pay attention and are
preoccupied with things they consider more important.

Wrong.

I've been a child, I remember being able to see sideways.

Doesnt mean that you always had the same
amount of peripheral vision when a young child.

Yip,

Nope.

it was measured.

It wasnt measured then and now and the results compared.

Was too. Just over 180 degrees, both times.

But not with all of the kids that it was initially measured with.

I remember us testing our eyesight in primary school for a
game/lesson, and it was similar then.

Then you didnt do it properly then.

Yes we did.

You clearly didnt if you concluded that all kids
have the same peripheral vision. They dont.

Similar. To within about 20 degrees per side. Everybody saw 180, some
more.

That nothing like what you previously said.

Yes it is. What do you believe I previously said?

Its still there in the quoting at the top. You previously
said all quite similar which nothing like as specific.

What are your experiences of cats vision

I dont remember actually testing that with any of the cats
I had and I dont currently have any cats that I can test.

Not easy to persuade a cat to look at something else while you're
doing something interesting.

These cats didnt need any persuading.
https://www.youtube.com/watch?v=KIeP...ature=youtu.be

I guess if one person distracted it maybe, but then you wouldn't
know
if it saw the second person to the side. You'd need something it
wanted to look at, then something even more exciting than that like
it's favourite treat.

With the neighbours' cats that love my jungle, they
normally dont look at me when I show up, they
mostly look where they are going while leaving.

Is that because you've just yelled at them?

Nope, I never yell at them in that situation.

The only cat I yell at is the ****er that insists on doing
a flying leap from the ground onto half way up my
****ing fly screen and then hanging onto the ****ing
fly screen with its claws in summer when its trying to
catch the moths.

Electrify the sunscreen.

Not possible, its plastic, not metal.

Change it then.

No point, much easier to shout at the cant to get it to stop doing that.

And nothing would happen even if it was metal.

You'd obviously have to have stripes of insulated sections, so the cat
touched two at once.

That wouldnt work either because cat's claws dont conduct.

Unless you like the moths.

It would have no effect on the moths.

Depends on how close the voltages were. Too close and it becomes an
insectocutor.

Too close and it wouldnt work for cats.

Mind you if you separated the high and low voltages enough, only a large
animal like a cat would get a shock.

I just shout at the cat and it ****s off.

After you've got a torn screen.

It has never torn the screen. Its a quite skinny light cat.

"whisky-dave" wrote in message
...
On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave
wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as
compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of
vision than men have. I believe this helps them nags us from any
direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be
colour blind.
This all goes back to our early ancestors in men they had to be quick to
hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and
scattter cushions while the men are hunting pints.


It's difficult to test yourself, have you ever tried tickling yourself
?.

Those are not comparable.

The human eye only looks at about 15% of it's view it sort of scans and
reports back to the brain.

But similar ideas.




Cats are better at seeing changes or fast movemnt rather than gradual
changes which they dont normally worry about.

That cat always worries about me.

So is used to you.



Secondly, I always find my cats looking straight at me or whatever
they want to examine,

same for most creatures, as the cnetre of the eye is usually the the
best for general viewing.

Yes, but you don't stare directly at a person for more than a second or
two. It doesn't take long to gather the details you need.


So cats don;t like diorect eye contact for very long as in teh animal
kingdon it's a threat, but in humans it doesn;t work like that, cats
reaslise this.


Have you ever noticed that some bulbs flicker out of the corner of your
eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half
of them when you're looking straight at them. Hard to believe in the
21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.



they don't seem to be able to see sideways, and the other day I walked
over to one cat, I was 90 degrees from his forward direction, and he
didn't see me until I touched him to stroke him, which scared the hell
out of him.

Maybe he was day dreaming.

He was licking his leg.

So explains it.
How can you can an accurate ID of the angle of a cats vision while it;s
washing it's leg.



What are your experiences of cats vision (and your own)?

Sometimes it sees a small fly or perhaps it hears it but it's following
something I just can't see myself.
Cat was on my lap the other night and sudeetnly she started staring
strangly at the window I tought it was something on the TV, but no it
was a bird on the TV areal across the road through the net curtains,
maybe some refelction or something made her suddently look up, but all
I could see was a bird on a TV areail which didn;t hold my inerest but
held hers for nearly 2 mins then she went back to sleep.

It's a simple life.

distrubed by something I didn't notice happening on a roof across the
road.

On Tue, 26 Apr 2016 21:47:17 +0100, Rod Speed wrote:



"whisky-dave" wrote in message
...
On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave
wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as
compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of
vision than men have. I believe this helps them nags us from any
direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be
colour blind.
This all goes back to our early ancestors in men they had to be quick to
hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and
scattter cushions while the men are hunting pints.


It's difficult to test yourself, have you ever tried tickling yourself
?.

Those are not comparable.

The human eye only looks at about 15% of it's view it sort of scans and
reports back to the brain.

But similar ideas.




Cats are better at seeing changes or fast movemnt rather than gradual
changes which they dont normally worry about.

That cat always worries about me.

So is used to you.



Secondly, I always find my cats looking straight at me or whatever
they want to examine,

same for most creatures, as the cnetre of the eye is usually the the
best for general viewing.

Yes, but you don't stare directly at a person for more than a second or
two. It doesn't take long to gather the details you need.


So cats don;t like diorect eye contact for very long as in teh animal
kingdon it's a threat, but in humans it doesn;t work like that, cats
reaslise this.


Have you ever noticed that some bulbs flicker out of the corner of your
eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half
of them when you're looking straight at them. Hard to believe in the
21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.

Then your eyes or brain are too slow. Remember the 60Hz CRT monitors, could you see those flicker?

--
Many contemplative moments spent I, squatting on a cold, sixteenth-century sandstone toilet bowl, its edges worn down by generations of shivering buttocks. -- Edward Radclyffe

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 19:39:29 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news
On Tue, 26 Apr 2016 10:43:13 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news On Tue, 26 Apr 2016 02:36:32 +0100, Rod Speed

wrote:



"Mr Macaw" wrote in message
news On Mon, 25 Apr 2016 23:00:22 +0100, Rod Speed

wrote:

Harry Bloomfield wrote
michael adams wrote

Meanwhile, back in the real world...

"The visual field of the human eye spans approximately 120
degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

That is one of the more superficial wikipedia articles.

My own test on myself, suggests mine is much wider than that close
to
200
degrees. Raise a finger of each hand concentrate on the PC screen,
move
the hands back at either side of the head, until the fingers
disappear
from view - 200 degrees.

Yeah, mine is something like that too. Much more than 120.

I don't believe anyone has 120 who doesn't have a severe eye defect.

Looks like we are using different measures, one and two eyes.
https://en.wikipedia.org/wiki/Peripheral_vision

One eye is irrelevant to the topic in hand - how far to your right can
you
see when staring straight ahead.

Yes, but it makes a big difference to the total you say.

My point is why was anyone looking up single eyes?

No one who matters is but the field of vision does get
stated both ways so you need to be clear which way
you are stating when you say what field of view you have.

Two eyes is the only sensible thing to look at in this context.

Yes, but that doesn't mean that some don't STATE it the other way.

You'd only talk about one eye if you were a doctor trying to figure out
what's wrong with it.

We aren't talking about one eye in the use sense,
just in the sense in which the angle is STATED.

You see things on your left with one eye and things on your right with
the
other. The field of vision of only one eye is useless information.

But some do state the field of view that way.

Both Wikipedia articles say it's just past right angles.

Which isnt all that different to the 200 Harry said he has.

I can believe 180, 200, 220, but I find it hard to believe many people
are
much below 180.

Quite a few primary school aged kids do.

My schoolchums weren't.

You don't know that. You never measured them when they were adults.

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 19:36:20 +0100, Rod Speed
wrote:



"Mr Macaw" wrote in message
news
On Tue, 26 Apr 2016 11:22:07 +0100, NY wrote:

"Mr Macaw" wrote in message
news "The visual field of the human eye spans approximately 120 degrees
of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

Wikipedia contradicts itself in another article:

No, the difference is whether you are talking about one or two eyes.

No, with one eye it says 100-110 degrees outwards and 60 degrees
towards
the nose. That makes 160-170 degrees.

Anyway, we were discussing sight, not sight with one eye shut. We
were
discussing how far round you can see an object when looking straight
ahead.

I presume "when looking straight ahead" means without swivelling your
eyes.
Maybe there should be two sets of figures with/without swivelling,
because
when you detect something on the periphery, you look towards it (by
swivelling the eyes) and then see a bit further round in that
direction.

200 degrees sounds incredibly high, but I've never tested my field of
view.
I would have guessed that it would be slightly under 180 degrees - but
that
it a guess without any testing. Maybe it *is* a realistic figure...

Easy enough to test yourself. I can see past right angles. I guess
some
people are more or less than others, but I wouldn't think by much.

Now what probably varies considerably is people's 3D field of view - if
you have a large bridge on your nose, it will obstruct the view from one
of your eyes.

Perhaps this is why people with cute little noses do better in a lot of
sports.

What is the evidence that they do ?

It's a good theory. It's a sign they have better made bodies,

That is very arguable with the blacks particularly.

and it also means both eyes can see further.

I doubt they can with peripheral vision.

Can you list some example of individuals like that ?

Jessica Ennis.

She isnt dramatically better at sports than those with bigger noses.

And she's into track and field where being able to see better is irrelevant
anyway.

"Mr Macaw" wrote in message news
On Tue, 26 Apr 2016 21:47:17 +0100, Rod Speed
wrote:



"whisky-dave" wrote in message
...
On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave
wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as
compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of
vision than men have. I believe this helps them nags us from any
direct.

Are you sure that isn't a myth like them being able to see more
colours?

they can it's not a myth anymore than it's more common for men to be
colour blind.
This all goes back to our early ancestors in men they had to be quick to
hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and
scattter cushions while the men are hunting pints.


It's difficult to test yourself, have you ever tried tickling
yourself
?.

Those are not comparable.

The human eye only looks at about 15% of it's view it sort of scans
and
reports back to the brain.

But similar ideas.




Cats are better at seeing changes or fast movemnt rather than gradual
changes which they dont normally worry about.

That cat always worries about me.

So is used to you.



Secondly, I always find my cats looking straight at me or whatever
they want to examine,

same for most creatures, as the cnetre of the eye is usually the the
best for general viewing.

Yes, but you don't stare directly at a person for more than a second or
two. It doesn't take long to gather the details you need.


So cats don;t like diorect eye contact for very long as in teh animal
kingdon it's a threat, but in humans it doesn;t work like that, cats
reaslise this.


Have you ever noticed that some bulbs flicker out of the corner of
your
eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half
of them when you're looking straight at them. Hard to believe in the
21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.

Then your eyes or brain are too slow.

Nope, that is another thing that varys considerably with people.

Remember the 60Hz CRT monitors, could you see those flicker?

Nope, and never got any flicker with the long
tube fluoros out of the corner of my eye either.

Some did, but I didn't.

On Tue, 26 Apr 2016 04:18:26 -0700, whisky-dave wrote:

On Tuesday, 26 April 2016 10:05:49 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:14:27 +0100, dennis@home
wrote:

On 26/04/2016 00:21, Mr Macaw wrote:

Simple experiment. A hula hoop around your head, with a coloured
bead slid slowly round it, while you stare straight ahead. You
shout out the colour when you see it.

That would be a couple of degrees then as rods don't detect colour
only cones do that and they are in the centre of your field of view.
Any colour you see in the peripheral field is just made up by your
brain.

Funny how my eyesight and everyone in the class worked with colour
round there. The only thing you don't pick up colour with is very low
light levels.

you'll have to define seeing and looking.
See if you can read a newspaper out of the corner of your eye. If you
can't youre not really seeing are you?

Most people think their eyes present the full picture, ready formed, as
perceived in their visual cortex when in fact the perceived image is
effectively a virtual reality construct of what your eyes have scanned
during the initial few seconds it took to take in the scene before them
and which continue to refresh and update the scene as you move within and
around the scenery.

In fact, apart from the very narrow angle of high definition[1] offered
by the fovea, most of the near peripheral, out to the periphery provides
low definition 'place marker' information to assist in keeping this
virtual image up to date, assisted by almost unconscious continual
scanning[2] of the scene by the beholder.

The visual cortex complexity represents in excess of 500 million years
worth of evolutionary development. Even so, the visual cortex uses many
shortcuts and 'cheat's to provide timely information of our immediate
environment, shortcuts and 'cheats' that in nature' serve us very well.
However, such 'winging it' methods of visual processing can be readily
demonstrated by testing with artificially created scenes designed to
induce 'optical illusions'.

Just remember that what you think you see is exactly that! It's just
what you *think* you are seeing. The virtual reality machine inside your
head keeps itself so well synchronised with the observed reality around
you that it *is* the reality (well for over 90% of the time in most
circumstances, barring deliberately crafted scenes designed to fool your
visual cortex).

Incidentally, I'm often distracted by the view out of the rear window of
our staircase which is at 90 degrees off axis to my view of the computer
monitor whenever any of our neighbours, during the day, move around their
back garden which backs onto our own back garden whilst I have my
'office' door open. IOW, my peripheral vision seems to be performing as
mother nature intended, a visual perimeter alarm sensor of movement.

[1] To prove how small the effective angle of high acuity is, just
concentrate on the word "visual" in the bottom line of the preceding
paragraph and see, without cheating, if you can actually make out the
last letter of the following word.

[2] One example of such 'unconscious' aspects of scanning a scene is the
automatic blanking out of the jumbled image information reaching the
visual cortex as you cast your gaze between various objects in the scene
before you.

If you use an analogue camera and monitor and pan and tilt the camera to
various parts of a scene, you will observe a blurred image on the monitor
during the pan and tilt motions, yet do the same using your eyes to
directly view the scene and such 'blurring' is entirely absent. Indeed it
is simply 'blanked out' or, more accurately, discarded as 'noise' by the
visual cortex.

--
Johnny B Good

On Wed, 27 Apr 2016 00:19:36 +0100, Johnny B Good wrote:

On Tue, 26 Apr 2016 04:18:26 -0700, whisky-dave wrote:

On Tuesday, 26 April 2016 10:05:49 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 09:14:27 +0100, dennis@home
wrote:

On 26/04/2016 00:21, Mr Macaw wrote:

Simple experiment. A hula hoop around your head, with a coloured
bead slid slowly round it, while you stare straight ahead. You
shout out the colour when you see it.

That would be a couple of degrees then as rods don't detect colour
only cones do that and they are in the centre of your field of view.
Any colour you see in the peripheral field is just made up by your
brain.

Funny how my eyesight and everyone in the class worked with colour
round there. The only thing you don't pick up colour with is very low
light levels.

you'll have to define seeing and looking.
See if you can read a newspaper out of the corner of your eye. If you
can't youre not really seeing are you?

Most people think their eyes present the full picture, ready formed, as
perceived in their visual cortex when in fact the perceived image is
effectively a virtual reality construct of what your eyes have scanned
during the initial few seconds it took to take in the scene before them
and which continue to refresh and update the scene as you move within and
around the scenery.

In fact, apart from the very narrow angle of high definition[1] offered
by the fovea, most of the near peripheral, out to the periphery provides
low definition 'place marker' information to assist in keeping this
virtual image up to date, assisted by almost unconscious continual
scanning[2] of the scene by the beholder.

The visual cortex complexity represents in excess of 500 million years
worth of evolutionary development. Even so, the visual cortex uses many
shortcuts and 'cheat's to provide timely information of our immediate
environment, shortcuts and 'cheats' that in nature' serve us very well..
However, such 'winging it' methods of visual processing can be readily
demonstrated by testing with artificially created scenes designed to
induce 'optical illusions'.

Just remember that what you think you see is exactly that! It's just
what you *think* you are seeing. The virtual reality machine inside your
head keeps itself so well synchronised with the observed reality around
you that it *is* the reality (well for over 90% of the time in most
circumstances, barring deliberately crafted scenes designed to fool your
visual cortex).

Incidentally, I'm often distracted by the view out of the rear window of
our staircase which is at 90 degrees off axis to my view of the computer
monitor whenever any of our neighbours, during the day, move around their
back garden which backs onto our own back garden whilst I have my
'office' door open. IOW, my peripheral vision seems to be performing as
mother nature intended, a visual perimeter alarm sensor of movement.

[1] To prove how small the effective angle of high acuity is, just
concentrate on the word "visual" in the bottom line of the preceding
paragraph and see, without cheating, if you can actually make out the
last letter of the following word.

Did it, and the next, but not the third word. 19" 4:3 monitor 15 inches from my face. Gap from centre of "visual" to end of "perimeter" = 22mm, gap from centre of "visual" to end of "alarm" = 33.5mm.

[2] One example of such 'unconscious' aspects of scanning a scene is the
automatic blanking out of the jumbled image information reaching the
visual cortex as you cast your gaze between various objects in the scene
before you.

I've felt really confused when I'm lying in bed and see a clock radio LED digital time with one eye, but it's blocked by the pillow with the other eye. The room is dark so my brain doesn't know the pillow is in the way. It can't understand why the clock is only visible with one eye.

If you use an analogue camera and monitor and pan and tilt the camera to
various parts of a scene, you will observe a blurred image on the monitor
during the pan and tilt motions, yet do the same using your eyes to
directly view the scene and such 'blurring' is entirely absent. Indeed it
is simply 'blanked out' or, more accurately, discarded as 'noise' by the
visual cortex.

If I scan round my room, I do see blur if I think about it, but it's usually subconsciously ignored. And usually my gaze will jump quickly from one point to another, so the blur doesn't last long.

That's another amazing thing you can do. Open a book and select a word. Now look around the room, then look back to the same word in the book, you remember precisely where it is and how much movement your head and eyes need to make to get to it. I assume it's like you were saying above, you have a mental image of the whole room, and you're just moving back to concentrate on a known part of it.

--
In the 60's people took acid to make the world weird.
Now the world is weird, people take prozac to make it normal.

On Tuesday, 26 April 2016 18:27:43 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 16:50:33 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of vision than men have. I believe this helps them nags us from any direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be colour blind.
This all goes back to our early ancestors in men they had to be quick to hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and scattter cushions while the men are hunting pints.

No it's not all women, just some.

In general women see more colours or rather have a beter perception of shades.

And I don't see how four cones helps anyway.

What you 'see' doesn't matter.
Facts will out-weigh what you see or think.

from yuor link below.
"study suggests that as many as 50% of women and 8% of men may have four photopigments and corresponding increased chromatic discrimination"



What's the point in having one inbetween two others? You can sense any colour between those two receptors by the brain analysing the strength of the signal from each receptor. Which is why we don't see three colours, but an infinite number.

we don;t see any infinite number.


https://en.wikipedia.org/wiki/Tetrachromacy

"In humans, two cone cell pigment genes are present on the X chromosome: the classical type 2 opsin genes OPN1MW and OPN1MW2. It has been suggested that humans with two X chromosomes could possess multiple cone cell pigments, perhaps born as full tetrachromats who have four simultaneously functioning kinds of cone cells, each type with a specific pattern of responsiveness to different wavelengths of light in the range of the visible spectrum.[16] One study suggested that 2-3% of the world's women might have the type of fourth cone whose sensitivity peak is between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.[17] Another study suggests that as many as 50% of women and 8% of men may have four photopigments and corresponding increased chromatic discrimination compared to trichromats.[16] In 2010, after 20 years of study of women with four types of cones (non-functional tetrachromats), neuroscientist Dr.. Gabriele Jordan
identified a woman (subject cDa29) who could detect a greater variety of colors than trichromats could, corresponding with a functional tetrachromat (or true tetrachromat).[18][19] Apes, Old World monkeys, and Humans normally have three types of cone cells and are therefore trichromats. However, at low light intensities, the rod cells may contribute to color vision, giving a small region of tetrachromacy in the color space;[20] human rod cells' sensitivity is greatest at a blueish-green wavelength."

So .....


It's difficult to test yourself, have you ever tried tickling yourself ?.

Those are not comparable.

But similar ideas.

What makes you think you can't test yourself? You know the way you're looking, and you know where the thing is you're trying to see.

yes that's the problem yuo are aware that something will become visible out of the corner of you eye and that is the problem.


Tickling, **** knows, that doesn't make sense.

you mean it doesn't to you.



Cats are better at seeing changes or fast movemnt rather than gradual changes which they dont normally worry about.

That cat always worries about me.

So is used to you.

And should have run away as I approached.

Why ?

Even if it wasn't scared of me, it should have noticed I was reaching over to stroke him, and not jump out of his skin when I touched him.

Why did he jump out of his skin. Think about this.

Now this is why you can't test yourself.
If the cat would have been testing himself he would have known when he was going to stroke himself wouldn;t he but he didn;t know when you were going to stroke him see how simple this is.


Secondly, I always find my cats looking straight at me or whatever they want to examine,

same for most creatures, as the cnetre of the eye is usually the the best for general viewing.

Yes, but you don't stare directly at a person for more than a second or two. It doesn't take long to gather the details you need.

So cats don;t like diorect eye contact for very long as in teh animal kingdon it's a threat, but in humans it doesn;t work like that, cats reaslise this.

They must then also realise it's considered annoying.

How do you know they have that sort or perceprion and why would they get annoyed.


Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

Nope, google for it and find thousands of people complaining about it.

Link ?
They are copmplaining about brightness not flickering.



they don't seem to be able to see sideways, and the other day I walked over to one cat, I was 90 degrees from his forward direction, and he didn't see me until I touched him to stroke him, which scared the hell out of him.

Maybe he was day dreaming.

He was licking his leg.

So explains it.
How can you can an accurate ID of the angle of a cats vision while it;s washing it's leg.

Can it not observe something approaching it while it's washing? So you not notice someone walking towards you when you're washing the dishes?

I don't move my head backwards forward and sideways or up and down while doing the dishes.

On Tuesday, 26 April 2016 21:56:41 UTC+1, Mr Macaw wrote:

All LED car tail-lights flicker out of the corner of your eye, and half
of them when you're looking straight at them. Hard to believe in the
21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.

Then your eyes or brain are too slow. Remember the 60Hz CRT monitors, could you see those flicker?

It could also be in your imagination., or teh flickering of yuor eyes.
Do you also see yoursefl blink.
Do you really see that your vision gets shutoff when you blink.
Is yuor brain too slow to see yuor own eyelids shut.
A blink of an eye is about 300ms 1/3 second so hwo the **** to yuo know whats going on when yuor eyes are closed for 1/3 second
Awnswer is you don;t your brain makes it up.

Of course now you'll claim your super human because you never see yuorself blink.

On Wednesday, 27 April 2016 00:35:39 UTC+1, Mr Macaw wrote:

That's another amazing thing you can do. Open a book and select a word. Now look around the room, then look back to the same word in the book, you remember precisely where it is and how much movement your head and eyes need to make to get to it. I assume it's like you were saying above, you have a mental image of the whole room, and you're just moving back to concentrate on a known part of it.

Yesp not so easy if someopne else has the book and has moved it.
This is why self testing is not valid.
Only you will know where the word is because only you looked at it with your eyes in yuor timeframe.



--
In the 60's people took acid to make the world weird.
Now the world is weird, people take prozac to make it normal.

whisky-dave wrote
Mr Macaw wrote

All LED car tail-lights flicker out of the corner of your eye, and
half
of them when you're looking straight at them. Hard to believe in
the 21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.

Then your eyes or brain are too slow. Remember the 60Hz CRT monitors,
could you see those flicker?

It could also be in your imagination.,

Nope, trivial to prove that it isn't with a proper double blind test.

or teh flickering of yuor eyes.

Nope, trivial to prove that it isn't that either.

Do you also see yoursefl blink.

You do if you watch for it.

Do you really see that your vision gets shutoff when you blink.
Is yuor brain too slow to see yuor own eyelids shut.

Nope.

A blink of an eye is about 300ms 1/3 second so hwo the **** to yuo
know whats going on when yuor eyes are closed for 1/3 second
Awnswer is you don;t your brain makes it up.

BULL****.

On Wed, 27 Apr 2016 10:47:33 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 21:56:41 UTC+1, Mr Macaw wrote:

All LED car tail-lights flicker out of the corner of your eye, and half
of them when you're looking straight at them. Hard to believe in the
21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

It is, I don't get that effect at all.

Then your eyes or brain are too slow. Remember the 60Hz CRT monitors, could you see those flicker?

It could also be in your imagination., or teh flickering of yuor eyes.
Do you also see yoursefl blink.
Do you really see that your vision gets shutoff when you blink.
Is yuor brain too slow to see yuor own eyelids shut.
A blink of an eye is about 300ms 1/3 second so hwo the **** to yuo know whats going on when yuor eyes are closed for 1/3 second
Awnswer is you don;t your brain makes it up.

Of course now you'll claim your super human because you never see yuorself blink.

Go read up on it. People can detect flicker up to anywhere from 50 to 100Hz depending on their eyesight/brain speed. Pigeons are 120Hz, which is why you shouldn't use ballast fluorescents in their dovecots.

--
A great way to lose weight is to eat naked in front of a mirror. Restaurants will almost always throw you out before you can eat too much.

On Wed, 27 Apr 2016 10:55:42 +0100, whisky-dave wrote:

On Wednesday, 27 April 2016 00:35:39 UTC+1, Mr Macaw wrote:

That's another amazing thing you can do. Open a book and select a word. Now look around the room, then look back to the same word in the book, you remember precisely where it is and how much movement your head and eyes need to make to get to it. I assume it's like you were saying above, you have a mental image of the whole room, and you're just moving back to concentrate on a known part of it.

Yesp not so easy if someopne else has the book and has moved it.
This is why self testing is not valid.
Only you will know where the word is because only you looked at it with your eyes in yuor timeframe.

That does no such thing as prove all self testing is invalid.

--
Maybe . . .
Flying saucers are real and the Air Force doesn't exist.

On Wed, 27 Apr 2016 10:36:57 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 18:27:43 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 16:50:33 +0100, whisky-dave wrote:

On Tuesday, 26 April 2016 14:37:46 UTC+1, Mr Macaw wrote:
On Tue, 26 Apr 2016 12:03:27 +0100, whisky-dave wrote:

On Monday, 25 April 2016 19:57:14 UTC+1, Mr Macaw wrote:
http://www.huffingtonpost.com/2013/1...n_4097761.html

"cats have a visual field that spans a whopping 200 degrees, as compared to 180 degrees in humans"

It also depends on teh individual women tend to have a wider filed of vision than men have. I believe this helps them nags us from any direct.

Are you sure that isn't a myth like them being able to see more colours?

they can it's not a myth anymore than it's more common for men to be colour blind.
This all goes back to our early ancestors in men they had to be quick to hunt women has to recognise cours for differmnt type of fruit and veg.
WHich is also why generally omen are bettere at picking out curtains and scattter cushions while the men are hunting pints.

No it's not all women, just some.

In general women see more colours or rather have a beter perception of shades.

No, a few % do. The rest are just damn fussy. Why should a certain colour "go with" or "clash with" another colour?

And I don't see how four cones helps anyway.

What you 'see' doesn't matter.
Facts will out-weigh what you see or think.

from yuor link below.
"study suggests that as many as 50% of women and 8% of men may have four photopigments and corresponding increased chromatic discrimination"

Also "One study suggested that 2-3% of the world's women might have the type of fourth cone" - so they just don't know. You'd think they could do autopsies on their eyes.

What's the point in having one inbetween two others? You can sense any colour between those two receptors by the brain analysing the strength of the signal from each receptor. Which is why we don't see three colours, but an infinite number.

we don;t see any infinite number.

You can certainly distinguish all 16 million that a 24 bit graphics card can output. 16 million, nowhere near 3.

https://en.wikipedia.org/wiki/Tetrachromacy

"In humans, two cone cell pigment genes are present on the X chromosome: the classical type 2 opsin genes OPN1MW and OPN1MW2. It has been suggested that humans with two X chromosomes could possess multiple cone cell pigments, perhaps born as full tetrachromats who have four simultaneously functioning kinds of cone cells, each type with a specific pattern of responsiveness to different wavelengths of light in the range of the visible spectrum.[16] One study suggested that 2-3% of the world's women might have the type of fourth cone whose sensitivity peak is between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.[17] Another study suggests that as many as 50% of women and 8% of men may have four photopigments and corresponding increased chromatic discrimination compared to trichromats.[16] In 2010, after 20 years of study of women with four types of cones (non-functional tetrachromats), neuroscientist Dr. Gabriele Jordan
identified a woman (subject cDa29) who could detect a greater variety of colors than trichromats could, corresponding with a functional tetrachromat (or true tetrachromat).[18][19] Apes, Old World monkeys, and Humans normally have three types of cone cells and are therefore trichromats. However, at low light intensities, the rod cells may contribute to color vision, giving a small region of tetrachromacy in the color space;[20] human rod cells' sensitivity is greatest at a blueish-green wavelength."

So .....

It's difficult to test yourself, have you ever tried tickling yourself ?.

Those are not comparable.

But similar ideas.

What makes you think you can't test yourself? You know the way you're looking, and you know where the thing is you're trying to see.

yes that's the problem yuo are aware that something will become visible out of the corner of you eye and that is the problem.

But you don't know when. Unless you're in the habit of lying to yourself, the test is fine.

Tickling, **** knows, that doesn't make sense.

you mean it doesn't to you.

Explain to me why it works only if someone else does it then. It's not like BOO! where you know it's going to happen. Even if your friend warns you he's going to tickle you, it' still tickles.

Having said that, try to scratch the sole of your foot with your fingernails without tickling yourself.

Cats are better at seeing changes or fast movemnt rather than gradual changes which they dont normally worry about.

That cat always worries about me.

So is used to you.

And should have run away as I approached.

Why ?

Because it's scared of me. It runs away if I approach it and he's seen me.

Even if it wasn't scared of me, it should have noticed I was reaching over to stroke him, and not jump out of his skin when I touched him.

Why did he jump out of his skin. Think about this.

Because he didn't know I was there - ergo he has tunnel vision.

Now this is why you can't test yourself.
If the cat would have been testing himself he would have known when he was going to stroke himself wouldn;t he but he didn;t know when you were going to stroke him see how simple this is.

Eye tests are nothing to do with knowing a frightening thing is going to occur. Clearly most things you can test yourself, like how heavy a weight can you benchpress. I suppose you'd say "Ah but you know the weight is too heavy, so you lift it anyway".

Secondly, I always find my cats looking straight at me or whatever they want to examine,

same for most creatures, as the cnetre of the eye is usually the the best for general viewing.

Yes, but you don't stare directly at a person for more than a second or two. It doesn't take long to gather the details you need.

So cats don;t like diorect eye contact for very long as in teh animal kingdon it's a threat, but in humans it doesn;t work like that, cats reaslise this.

They must then also realise it's considered annoying.

How do you know they have that sort or perceprion and why would they get annoyed.

No, *I* get annoyed, and they should have remembered from last time. Only goldfish forget.

Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

Are you sure it's not just you.

Nope, google for it and find thousands of people complaining about it.

Link ?
They are copmplaining about brightness not flickering.

That's daytime running lights.

LED taillight flicker, loads of results:
https://www.google.co.uk/search?clie...UTF-8&oe=UTF-8

they don't seem to be able to see sideways, and the other day I walked over to one cat, I was 90 degrees from his forward direction, and he didn't see me until I touched him to stroke him, which scared the hell out of him.

Maybe he was day dreaming.

He was licking his leg.

So explains it.
How can you can an accurate ID of the angle of a cats vision while it;s washing it's leg.

Can it not observe something approaching it while it's washing? So you not notice someone walking towards you when you're washing the dishes?

I don't move my head backwards forward and sideways or up and down while doing the dishes.

You don't need to, as you can see out of the corner of your eye.

--
Her face was a perfect oval, like a circle that had its two other sides gently compressed by a Thigh Master.

"Mr Macaw" wrote in message news
Go read up on it. People can detect flicker up to anywhere from 50 to
100Hz depending on their eyesight/brain speed. Pigeons are 120Hz, which
is why you shouldn't use ballast fluorescents in their dovecots.

I could tell the difference between a 50 Hz UK TV broadcast and a 60 Hz US
one, played on the same CRT TV. Especially if I saw the TV out of the corner
of my eye - apparently peripheral vision is particularly sensitive to
flicker and movement.

Likewise for 60 Hz non-interlaced computer screen versus 70, 75, 85 or 100
Hz; the latter all looked equally steady, so evidently for me the threshold
is between 60 and 70 for non-interlaced and between 50 and 60 for
interlaced.

I think the blinking analogy might be a bit spurious. I think the brain is
*aware* of the momentary loss of picture but chooses to ignore it and to
fill in the gap.

I was always a bit sceptical of the claims of subliminal advertising
allowing unscrupulous advertisers to "plant" ideas such as "Buy XYZ brand
Cola" in unsuspecting customers' minds, because I could certainly detect a
single frame at 24/25 fps if it was different to all the others. I may not
know what was on that frame, but I'd immediately know "that was odd" and I'd
wind the tape/MPEG back for a second look or play it frame by frame if the
technology allowed, so it wouldn't exactly go unnoticed!

"Mr Macaw" wrote in message news
WHich is also why generally omen are bettere at picking out curtains
and scattter cushions while the men are hunting pints.

No it's not all women, just some.

In general women see more colours or rather have a beter perception of
shades.

No, a few % do. The rest are just damn fussy. Why should a certain
colour "go with" or "clash with" another colour?

I wonder if it's that some women have a lower tolerance to "that's close
enough" and are more exacting, whereas some men think "that'll do, now let
me concentrate on something more interesting".

Colour perception is a very strange thing. Do you remember that picture of a
dress (possibly a bride's mother's outfit for a wedding) that was in the
news last year. Some people saw it as gold and some as black. My wife and I
both swore blind that it was one colour or the other (we saw different) and
could not see the opposite colour even when we knew the alternative
perception. It turned out that the actual colour (by looking at relative
intensities of RGB) was the one that I couldn't see, and that I was one of
the people who were fooled by the blue background and mentally corrected for
what we perceived as a tungsten-versus-daylight colour cast in the whole
photo. I forget what the proportions were of people who saw the dress as one
colour or the other, but it was far more evenly balanced than the proportion
of people with normal colour vision versus those with one the the various
types of colour blindness.

On Wed, 27 Apr 2016 15:53:55 +0100, NY wrote:

"Mr Macaw" wrote in message news
Go read up on it. People can detect flicker up to anywhere from 50 to
100Hz depending on their eyesight/brain speed. Pigeons are 120Hz, which
is why you shouldn't use ballast fluorescents in their dovecots.

I could tell the difference between a 50 Hz UK TV broadcast and a 60 Hz US
one, played on the same CRT TV. Especially if I saw the TV out of the corner
of my eye - apparently peripheral vision is particularly sensitive to
flicker and movement.

Likewise for 60 Hz non-interlaced computer screen versus 70, 75, 85 or 100
Hz; the latter all looked equally steady, so evidently for me the threshold
is between 60 and 70 for non-interlaced and between 50 and 60 for
interlaced.

I used to be a computer tech in the days of 60Hz monitors, and whenever I commented on someone's monitor flickering, about 1 in 5 would agree, and the others wouldn't know what I was talking about. The ones that agreed I bought them a 90Hz Iiyama and they loved it.

I think the blinking analogy might be a bit spurious. I think the brain is
*aware* of the momentary loss of picture but chooses to ignore it and to
fill in the gap.

I was always a bit sceptical of the claims of subliminal advertising
allowing unscrupulous advertisers to "plant" ideas such as "Buy XYZ brand
Cola" in unsuspecting customers' minds, because I could certainly detect a
single frame at 24/25 fps if it was different to all the others. I may not
know what was on that frame, but I'd immediately know "that was odd" and I'd
wind the tape/MPEG back for a second look or play it frame by frame if the
technology allowed, so it wouldn't exactly go unnoticed!

Agreed, I'd spot a frame too. It's called persistence of vision or something, similar to how they make dim LEDs appear brighter by pulsing them at brighter levels than they're capable of normally, so they don't overheat. The trouble is they seem to think we can't see the flicker.

--
They say Confucius does his crosswords with a pen.

On Wed, 27 Apr 2016 16:02:33 +0100, NY wrote:

"Mr Macaw" wrote in message news
WHich is also why generally omen are bettere at picking out curtains
and scattter cushions while the men are hunting pints.

No it's not all women, just some.

In general women see more colours or rather have a beter perception of
shades.

No, a few % do. The rest are just damn fussy. Why should a certain
colour "go with" or "clash with" another colour?

I wonder if it's that some women have a lower tolerance to "that's close
enough" and are more exacting, whereas some men think "that'll do, now let
me concentrate on something more interesting".

I can tell the difference between colours very easily - if I'm trying to patch up a damaged wall and can't get the precise paint colour, it annoys me. But I just don't understand how a woman can say "you can't wear orange and blue at the same time." Why not? Why should orange and blue be wrong when both are right individually?

Colour perception is a very strange thing. Do you remember that picture of a
dress (possibly a bride's mother's outfit for a wedding) that was in the
news last year. Some people saw it as gold and some as black. My wife and I
both swore blind that it was one colour or the other (we saw different) and
could not see the opposite colour even when we knew the alternative
perception. It turned out that the actual colour (by looking at relative
intensities of RGB) was the one that I couldn't see, and that I was one of
the people who were fooled by the blue background and mentally corrected for
what we perceived as a tungsten-versus-daylight colour cast in the whole
photo. I forget what the proportions were of people who saw the dress as one
colour or the other, but it was far more evenly balanced than the proportion
of people with normal colour vision versus those with one the the various
types of colour blindness.

I saw it as light blue and gold. Which is what the photo was. You can see it in the link below, and if you put it into a photo editor you'll see the lighter areas have more B than R and G. And the darker areas have way too much intensity for black. It's the camera that got it wrong, nothing to do with colour perception. If you're seeing anything other than light blue and gold, either your eyes are ****ed up, or your monitor is very dark.

https://en.wikipedia.org/wiki/The_dr...ral_phenomenon)

--
Why is it that when you transport something by car, it's called a shipment, but when you transport something by ship, it's called cargo?

"Mr Macaw" wrote in message news
I saw it as light blue and gold. Which is what the photo was. You can
see it in the link below, and if you put it into a photo editor you'll see
the lighter areas have more B than R and G. And the darker areas have way
too much intensity for black. It's the camera that got it wrong, nothing
to do with colour perception. If you're seeing anything other than light
blue and gold, either your eyes are ****ed up, or your monitor is very
dark.

https://en.wikipedia.org/wiki/The_dr...ral_phenomenon)

Yes that's what I saw it as: white and gold. Or at least I saw it as very
pale blue and gold which I interpreted as white-and-gold with the camera set
for tungsten light and looking at daylight illumination - such a common
error (like the converse one) that the brain corrects for it.

How badly exposed and lit must it have been for black to reproduce as gold?

It's interesting that the majority of people saw it as it was supposed to be
rather than as it was actually portrayed in the photo. Of a very limited
sample (my wife, my sister, my brother in law and my parents) it was the
women who saw it as blue and black and the men who saw it as white (or pale
blue) and gold, despite the Wikipedia article saying that it was women who
disproportionately saw it as white/gold.

I wonder whether my wife/sister/mum might have been influenced by knowing
from the style/pattern of the dress what colours it was likely to be ("this
pattern is only made in these colours") whereas men may have had no prior
knowledge and saw so saw what was depicted.

On Wed, 27 Apr 2016 17:16:05 +0100, NY wrote:

"Mr Macaw" wrote in message news
I saw it as light blue and gold. Which is what the photo was. You can
see it in the link below, and if you put it into a photo editor you'll see
the lighter areas have more B than R and G. And the darker areas have way
too much intensity for black. It's the camera that got it wrong, nothing
to do with colour perception. If you're seeing anything other than light
blue and gold, either your eyes are ****ed up, or your monitor is very
dark.

https://en.wikipedia.org/wiki/The_dr...ral_phenomenon)

Yes that's what I saw it as: white and gold. Or at least I saw it as very
pale blue and gold which I interpreted as white-and-gold with the camera set
for tungsten light and looking at daylight illumination - such a common
error (like the converse one) that the brain corrects for it.

How badly exposed and lit must it have been for black to reproduce as gold?

Probably taken on an Iphone, which some people seem to think passes for a camera.

It's interesting that the majority of people saw it as it was supposed to be
rather than as it was actually portrayed in the photo. Of a very limited
sample (my wife, my sister, my brother in law and my parents) it was the
women who saw it as blue and black and the men who saw it as white (or pale
blue) and gold, despite the Wikipedia article saying that it was women who
disproportionately saw it as white/gold.

I wonder whether my wife/sister/mum might have been influenced by knowing
from the style/pattern of the dress what colours it was likely to be ("this
pattern is only made in these colours") whereas men may have had no prior
knowledge and saw so saw what was depicted.

I don't see how anyone who isn't clinically insane could have seen black. Even if you knew the dress should be black, you'd say "Who bleached the dress?"

--
Why do blondes have more fun?
They are easier to keep amused.

"Mr Macaw" wrote in message news
I don't see how anyone who isn't clinically insane could have seen black.
Even if you knew the dress should be black, you'd say "Who bleached the
dress?"

Nor me. With a lot of these optical illusions or things that can be seen two
ways, I can say "well I see it this way but I suppose I can understand how
you might see it that way". But not with The Dress. I too find it impossible
to imagine how that vivid old-gold shade could be perceived as really being
black. And how many stops overexposure do you need to convert royal blue
into a very pale white-seen-under-daylight-by-camera-set-for-tungsten
colour?

I wonder if the background (daylight outside) is making a difference - if
the dress was "cut" out of the photo and placed against a neutral black,
white or grey background it would make it look any different.

I was *very* surprised to learn that the dress was actually blue and black
and that the majority of those in the test sample saw it that way, because
it's definitely not what the photo shows. Unless you have prior knowledge of
what colours it should be.

On Tuesday, 26 April 2016 18:27:43 UTC+1, Mr Macaw wrote:

No it's not all women, just some. And I don't see how four cones helps anyway. What's the point in having one inbetween two others? You can sense any colour between those two receptors by the brain analysing the strength of the signal from each receptor.

One can also see violet which is outside of the blue receptor peak. Blue light activates the blue receptor and to some extent the green one, violet only activates the blue one and the brain interprets it as violet.


Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

it makes them more noticable.


NT

On Wed, 27 Apr 2016 19:32:21 +0100, wrote:

On Tuesday, 26 April 2016 18:27:43 UTC+1, Mr Macaw wrote:

No it's not all women, just some. And I don't see how four cones helps anyway. What's the point in having one inbetween two others? You can sense any colour between those two receptors by the brain analysing the strength of the signal from each receptor.

One can also see violet which is outside of the blue receptor peak. Blue light activates the blue receptor and to some extent the green one, violet only activates the blue one and the brain interprets it as violet.

It's quite difficult to see violet.

Have you ever noticed that some bulbs flicker out of the corner of your eye but not when you look directly at them.

All LED car tail-lights flicker out of the corner of your eye, and half of them when you're looking straight at them. Hard to believe in the 21st century we get such ****ty lights (and on decent cars).

it makes them more noticable.

That's the problem. It's a distraction. What's the point in your attention being drawn to every single car?

--
"Quantititty" - noun. A measurement of the diameter of a woman's breast.

On Wed, 27 Apr 2016 18:10:57 +0100, NY wrote:

"Mr Macaw" wrote in message news
I don't see how anyone who isn't clinically insane could have seen black.
Even if you knew the dress should be black, you'd say "Who bleached the
dress?"

Nor me. With a lot of these optical illusions or things that can be seen two
ways, I can say "well I see it this way but I suppose I can understand how
you might see it that way". But not with The Dress. I too find it impossible
to imagine how that vivid old-gold shade could be perceived as really being
black. And how many stops overexposure do you need to convert royal blue
into a very pale white-seen-under-daylight-by-camera-set-for-tungsten
colour?

I wonder if the background (daylight outside) is making a difference - if
the dress was "cut" out of the photo and placed against a neutral black,
white or grey background it would make it look any different.

I was *very* surprised to learn that the dress was actually blue and black
and that the majority of those in the test sample saw it that way, because
it's definitely not what the photo shows. Unless you have prior knowledge of
what colours it should be.

Being a photographer myself (I used to take photos at motorbike races etc with a £3K digital SLR), it doesn't make any sense at all. If there's too much light in the background, a ****ty camera using average instead of point exposure would have made the dress too dark. I see no reason any camera would overexpose because of more light elsewhere. More light makes the camera expose less.

--
My wife and I were happy for twenty years. Then we met.

"Mr Macaw" wrote in message news
On Wed, 27 Apr 2016 16:02:33 +0100, NY wrote:

"Mr Macaw" wrote in message
news
WHich is also why generally omen are bettere at picking out curtains
and scattter cushions while the men are hunting pints.

No it's not all women, just some.

In general women see more colours or rather have a beter perception of
shades.

No, a few % do. The rest are just damn fussy. Why should a certain
colour "go with" or "clash with" another colour?

I wonder if it's that some women have a lower tolerance to "that's close
enough" and are more exacting, whereas some men think "that'll do, now
let
me concentrate on something more interesting".

I can tell the difference between colours very easily - if I'm trying to
patch up a damaged wall and can't get the precise paint colour, it annoys
me. But I just don't understand how a woman can say "you can't wear
orange and blue at the same time." Why not? Why should orange and blue
be wrong when both are right individually?

I don't know why not, but it is a real effect.

If you don't mind a melt down between the ears, try this
https://en.wikipedia.org/wiki/Impossible_color

Colour perception is a very strange thing. Do you remember that picture
of a
dress (possibly a bride's mother's outfit for a wedding) that was in the
news last year. Some people saw it as gold and some as black. My wife and
I
both swore blind that it was one colour or the other (we saw different)
and
could not see the opposite colour even when we knew the alternative
perception. It turned out that the actual colour (by looking at relative
intensities of RGB) was the one that I couldn't see, and that I was one
of
the people who were fooled by the blue background and mentally corrected
for
what we perceived as a tungsten-versus-daylight colour cast in the whole
photo. I forget what the proportions were of people who saw the dress as
one
colour or the other, but it was far more evenly balanced than the
proportion
of people with normal colour vision versus those with one the the various
types of colour blindness.

I saw it as light blue and gold. Which is what the photo was. You can
see it in the link below, and if you put it into a photo editor you'll see
the lighter areas have more B than R and G. And the darker areas have way
too much intensity for black. It's the camera that got it wrong, nothing
to do with colour perception.

Your cite below says the exact opposite.

If you're seeing anything other than light blue and gold, either your eyes
are ****ed up, or your monitor is very dark.

https://en.wikipedia.org/wiki/The_dr...ral_phenomenon)

"Mr Macaw" wrote in message news
On Wed, 27 Apr 2016 17:16:05 +0100, NY wrote:

"Mr Macaw" wrote in message
news
I saw it as light blue and gold. Which is what the photo was. You can
see it in the link below, and if you put it into a photo editor you'll
see
the lighter areas have more B than R and G. And the darker areas have
way
too much intensity for black. It's the camera that got it wrong,
nothing
to do with colour perception. If you're seeing anything other than
light
blue and gold, either your eyes are ****ed up, or your monitor is very
dark.

https://en.wikipedia.org/wiki/The_dr...ral_phenomenon)

Yes that's what I saw it as: white and gold. Or at least I saw it as very
pale blue and gold which I interpreted as white-and-gold with the camera
set
for tungsten light and looking at daylight illumination - such a common
error (like the converse one) that the brain corrects for it.

How badly exposed and lit must it have been for black to reproduce as
gold?

Probably taken on an Iphone, which some people seem to think passes for a
camera.

It's interesting that the majority of people saw it as it was supposed to
be
rather than as it was actually portrayed in the photo. Of a very limited
sample (my wife, my sister, my brother in law and my parents) it was the
women who saw it as blue and black and the men who saw it as white (or
pale
blue) and gold, despite the Wikipedia article saying that it was women
who
disproportionately saw it as white/gold.

I wonder whether my wife/sister/mum might have been influenced by knowing
from the style/pattern of the dress what colours it was likely to be
("this
pattern is only made in these colours") whereas men may have had no prior
knowledge and saw so saw what was depicted.

I don't see how anyone who isn't clinically insane could have seen black.

They did anyway, and if you can understand why,
you will understand color perception much better.

Even if you knew the dress should be black, you'd say "Who bleached the
dress?"

Not if you see the gold bands as black you wouldn't.