In article
,
DerbyDad03 wrote:

I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

On Jul 16, 12:57*pm, Smitty Two wrote:
In article
,

*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

On Jul 16, 9:19*am, DerbyDad03 wrote:
On Jul 16, 12:22*am, harry k wrote:





On Jul 15, 11:05*am, DerbyDad03 wrote:

On Jul 14, 11:20*pm, harry k wrote:

On Jul 14, 3:41*pm, Smitty Two wrote:

In article
,
*harry k wrote:

On Jul 13, 10:22*pm, Smitty Two wrote:
In article
,
*harry k wrote:

Nope. *It is strobing. *In some of the old films you can see a wheel
go backwards, slow, forwards. *That is caused by the wheel speed
changing.

Harry K

Have you actually seen the commercials, Harry? I'd be surprised if you
saw them and stuck by your wagon wheel effect hypothesis. In the
screwdriver commercial, it doesn't matter whether you look at the chuck,
the driver bit, or the screw, it's rotating the wrong way, quite clearly
and a very stable rate.

Of course it is an so is every part of it, they are all fixed and
therefore rotate together. *Vary the speed of the drill and you would
see the rotation slow, speed up or even reverse direction.

You must have missed that demonstration in the HS physics course.

Harry K

No, I didn't miss it. HAVE YOU SEEN THE COMMERCIAL? IF SO, do you STILL
think it is the wagon wheel effect ???????- Hide quoted text -

- Show quoted text -

One more time and I am done. *I DO NOT HAVE TO SEE THE COMMERCIAL..
You have described an everyday, common effect of strobing. *I don't
need to see the sun come up to know that is what happened when some
kook tries to explain daylight by some other method.

Try doing a google on 'stroboscopic effect' - I would be surprised if
you don't find a lot of sources explaining it and even some clips
showing it.

You have been told by several people what it is, that you don't want
to accept it...

Harry K- Hide quoted text -

- Show quoted text -

"I don't need to see the sun come up to know that is what happened
when some kook tries to explain daylight by some other method."

That's because there is no other explanation for daylight.

However, regardless of the existance of the "common effect of
strobing" there also exists a number of other reasons for the bit to
appear to be rotating backwards, the obvious one being that it
actually is rotating backwards.

There's also the possibility of the film being a "mirror image" of the
actual event.

I'm not claiming that the cause *isn't* the "common effect of
strobing" - although I seriously doubt that in this case it is - I'm
simply pointing out that your argument for not needing to see the
commercial based on the fact that the sun causes daylight is flawed.- Hide quoted text -

- Show quoted text -

True it is "possible" but Occam's razor comes into effect. *So fare
Smitty hasn't produced anything that would obviate the simple
solution.

Harry K- Hide quoted text -

- Show quoted text -

"Occam's razor comes into effect."

If you're going to play the Occam's Razor card, then the strobing
explanation should be the one that is thrown out.

"When you have two competing theories that make exactly the same
predictions, the simpler one is the better."

What's simpler: That the drill is actually running in reverse or that
the strobing effect is the cause?

I submit that the drill actually running in reverse is the simpler
explanation - IFF we are ranking the possible reasons for what we see
in terms of their complexity.

What's simpler: "Press this button and the drill spins one way or the
other." or "The *'stroboscopic effect' *is explained as follows..."

BTW: Smitty Two is not talking about the same commercial - or at least
not the same segment - as I am. The clip I saw was a wood boring bit,
not a drywall screw. I have not been able to find an on-line copy of
the commercial.

BTW-2: I'm not sure if one of my earlier questions has been answered,
so I'll ask it in a slightly different manner.

First, I know that the stroboscopic effect exists; I've seen wheels
"turning backwards", so I'm not questioning the existance of the
"wagon wheel" effect.

That said, let's assume that the perception of the drill turning
backwards *is* caused by the stroboscopic effect. Is the effect
actually captured on film/digital storage or is it just preceived by
the viewer when watching the clip? The reason I ask is that, as I have
mentioned before, when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse. If the effect
is captured on film, then obviously we would see it while watching the
commercial. However, if the effect is really just a "perception",
whether in real life or while viewing a commercial, then wouldn't one
have to assume that the fact that it is seen even when viewed frame by
frame means that there is some other explanation?- Hide quoted text -

- Show quoted text -

Good point on Occam's razor.

Good questions. Answer is Yes it is captured on _film_. I have been
wondering all day about digital recording though.

Frame by frame, assuming it is captured that way, would of course show
the strobe effect. It is a capture of one instant in a sequence and
thus does not have to played at any given speed to shwo the effect.

Harry K

On Jul 16, 11:26*am, DerbyDad03 wrote:
On Jul 16, 12:57*pm, Smitty Two wrote:

In article
,

*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

Now I wonder too. It used to be common, especially in westerns. I
can't recall seeing an example from other than old films.

Harry K

On Jul 16, 9:34*am, Smitty Two wrote:
In article
,
*harry k wrote:





On Jul 15, 9:42*pm, Smitty Two wrote:
In article
,
*harry k wrote:

Think about it for a minute: *All the parts are rotating together..
Right?
All the parts of a wheel rotate together. *Right? *So just what is
prepsterous about it?

Let's say there's 4 repeating features on the screwdriver bit (the
square sides), 3 chuck fingers, and 10 grooves around the outer diameter
of the chuck. The strobe couldn't make them all appear to turn backwards
at the same RPM. Oh, yeah, there's also the threads on the drywall type
screw that are turning backwards.

Well of course they all rotate at the same speed, they are fixed to
one another. In real life they are also rotating *at the same speed so
why wouldn't they in strobe effect? *The fact that some of them are
farther out from the axis does not effect their position when the
strobe hits. Somehow you seem to think that everything is rotating at
different rates

You could build a wheel 6' in diameter and tie rags aroudn the spokes
at diffent distances from the axle and they would all show the same
effect.
.
Harry K

It's an RPM (revolutions per minute) vs. RPM (repetitions per minute)
thing.

Yes all the parts rotate at the same actual RPM. But it is the
repetition of a regular feature (spokes) that causes the wagon wheel
illusion. If the drill is really turning at 100 RPM, then in my example
above, the frequency of the features going by your eye will be 400, 300,
and 1000 repetitions per minute. So as far as the wagon wheel effect is
concerned, the various parts of the drill are turning at different RPMs,
i.e. they couldn't all exhibit the effect at the same actual RPM.- Hide quoted text -

- Show quoted text -

The number of each feature doesn't matter. Look at a bicycle wheel
again. Many spokes (one would do) but only 1 valve stem. The drill
and all parts are all turning the same _rpm_. The features all appear
at the same time because they all come around together. The ones
being illuminated repeat all at the same repetition rate, I have been
puzzling all day how to explain that better but can't come up with a
way.


Okay. Now I see what you are doing. 4 sides to bit, 3 chuck fingers,
etc. It doesn't matter how many of anything shows up as the strobe
will light them all 'features' at the same time and they will all be
in the same physical relationship. It will, My example of rags tied
to spokes shows that. It doesn't matter how many spokes you tie them
to, the effect still operates.

I wonder if there is a cheap strobe light out there. They were fun to
play with back in HS physics.

Still wondering about digital recording.

Harry K

On Jul 16, 8:55*pm, harry k wrote:
On Jul 16, 9:34*am, Smitty Two wrote:





In article
,
*harry k wrote:

On Jul 15, 9:42*pm, Smitty Two wrote:
In article
,
*harry k wrote:

Think about it for a minute: *All the parts are rotating together.
Right?
All the parts of a wheel rotate together. *Right? *So just what is
prepsterous about it?

Let's say there's 4 repeating features on the screwdriver bit (the
square sides), 3 chuck fingers, and 10 grooves around the outer diameter
of the chuck. The strobe couldn't make them all appear to turn backwards
at the same RPM. Oh, yeah, there's also the threads on the drywall type
screw that are turning backwards.

Well of course they all rotate at the same speed, they are fixed to
one another. In real life they are also rotating *at the same speed so
why wouldn't they in strobe effect? *The fact that some of them are
farther out from the axis does not effect their position when the
strobe hits. Somehow you seem to think that everything is rotating at
different rates

You could build a wheel 6' in diameter and tie rags aroudn the spokes
at diffent distances from the axle and they would all show the same
effect.
.
Harry K

It's an RPM (revolutions per minute) vs. RPM (repetitions per minute)
thing.

Yes all the parts rotate at the same actual RPM. But it is the
repetition of a regular feature (spokes) that causes the wagon wheel
illusion. If the drill is really turning at 100 RPM, then in my example
above, the frequency of the features going by your eye will be 400, 300,
and 1000 repetitions per minute. So as far as the wagon wheel effect is
concerned, the various parts of the drill are turning at different RPMs,
i.e. they couldn't all exhibit the effect at the same actual RPM.- Hide quoted text -

- Show quoted text -

The number of each feature doesn't matter. *Look at a bicycle wheel
again. *Many spokes (one would do) but only 1 valve stem. * The drill
and all parts are all turning the same _rpm_. *The features all appear
at the same time because they all come around together. * The ones
being illuminated *repeat all at the same repetition rate, I have been
puzzling all day how to explain that better but can't come up with a
way.

Okay. *Now I see what you are doing. *4 sides to bit, 3 chuck fingers,
etc. *It doesn't matter how many of anything shows up as the strobe
will light them all 'features' at the same time and they will all be
in the same physical relationship. It will, * My example of rags tied
to spokes shows that. *It doesn't matter how many spokes you tie them
to, the effect still operates.

I wonder if there is a cheap strobe light out there. *They were fun to
play with back in HS physics.

Still wondering about digital recording.

Harry K- Hide quoted text -

- Show quoted text -

Another add on. Looking at it another way. The 'strobe' is in effect
a flashbulb. It shows what is there at the given instant, thus you
are looking at 1/2 (approximately) of the features (the ones facing
the strobe) all at the same time, not individually.

Harry K

On Thu, 16 Jul 2009 20:27:23 -0700 (PDT), harry k
wrote:

On Jul 16, 11:26*am, DerbyDad03 wrote:
On Jul 16, 12:57*pm, Smitty Two wrote:

In article
,

*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

Now I wonder too. It used to be common, especially in westerns. I
can't recall seeing an example from other than old films.

Harry K

Once again... The film frame rate was different than the 60 cycle
timing used as the basis for television video. If something is
recorded originally on video rather than film, it won't exhibit the
effect, because the original recording will have used the same 60
cycle standard as the TV used to reproduce it.

The reason it used to be more common is that today, less TV production
work is done using photographic film as the media.

In article
,
harry k wrote:

The number of each feature doesn't matter. Look at a bicycle wheel
again. Many spokes (one would do) but only 1 valve stem. The drill
and all parts are all turning the same rpm . The features all appear
at the same time because they all come around together. The ones
being illuminated repeat all at the same repetition rate, I have been
puzzling all day how to explain that better but can't come up with a
way.

Of course the number of features matter. This is the way the illusion
works:

In your mind, superimpose a four-spoke wheel on a clock face, with
spokes pointing to 12,3,6, and 9. Label the spokes A,B,C, and D,
respectively.

Now, turn the wheel clockwise. Let's say you turn it 1/6 revolution,
a.k.a. 60 degrees, a.k.a. "two hours" of rotation. So A is pointing to
2, B to 5, C to 8, and D to 11.

But during the rotation, turn off the light, close your eyes, whatever.
Now what happens in the mind is that it misinterprets what the eye sees.
It makes more sense to the mind that the spokes have each moved
backwards one hour, rather than forwards two hours.

So you think that A moved from 12 to 11, rather than from 12 to 2. Of
course, it isn't A that you're seeing at 11, it's D. But A and D look
the same, because they're identical spokes.

The mind wants to believe that while the lights were out, things moved
as little as possible. So it sees the rotation slowly in reverse, rather
than more quickly in forwards.

Now superimpose another set of different features, but say there's six
of them instead of four. Call them A2, B2, C2, D2, E2, F2. Now with each
60 degree rotational increment, each of those features also moves "two
hours." But they were already at 2 hour increments from one another (as
opposed to 3 hour increments for the 4-feature set.) So now, A2 takes
the exact place of B2, B2 takes the place of C2, etc. Result is that
this feature set will appear to stand still.

Finally let's look at a ten feature set, A3 through J3. Now they don't
all start out lined up with clockface numerals. A3 is lined up with 12
o'clock, and F3 is lined up with 6 o'clock, but the rest of them are
some fractional hours. So it will be easier to consider degrees of
rotation instead of clock readings.

360 degrees / 10 = 36 degrees. The last "spoke" (J3) in this feature set
is located at 360 - 36 = 324 degrees. After one 60 degree incremental
movement, A3 will be at 60 degrees, and J3 will be at 24 degrees. The
mind wants to see minimal change of position, so it now sees J3 as A3,
and believes that the wheel is rotating slowly clockwise (24 degrees per
increment instead of 60)

So, if you've followed this along, I hope you can see that the number of
features is critical to whether the mind sees forward motion, backward
motion, or a standstill, and that the apparent motion, either forwards
of backwards, is also slower than what's actually happening.

In the commercial, the different parts of the drill have different
numbers of features, so can't exhibit the same illusion at the same RPM.

In article
,
DerbyDad03 wrote:

On Jul 16, 12:57*pm, Smitty Two wrote:
In article
,

*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

Ah, sorry, I'm DVR impaired.


That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... seems we're down to you, me, and harry on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.

"Smitty Two" wrote in message
news
In article
,
DerbyDad03 wrote:

On Jul 16, 12:57 pm, Smitty Two wrote:
In article
,

DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

Ah, sorry, I'm DVR impaired.


That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... seems we're down to you, me, and harry on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.

if you look at video camera specs, they all have a "shutter speed" even
though there is no real shutter. that's the rate the computer can poll the
video chip, as it has to poll almost every location at very close to the
same time or you'd get smearing of the video picture.

thus, a video or film camera would still show the same phenomon of strobing
on rotating parts.

regards,
charlie
cave creek, az

wrote:
On Thu, 16 Jul 2009 20:27:23 -0700 (PDT), harry k
wrote:

On Jul 16, 11:26 am, DerbyDad03 wrote:
On Jul 16, 12:57 pm, Smitty Two wrote:

In article
,
DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.
snip
when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.
Step up to the plate in the name of science, and be the first to post
your clip online.
I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

If it is "wagon wheel" effect it would be on your DVR. If it were mirror
image it would be on your DVR and you would have to have a reference,
like text, to tell the difference. If it were video played in reverse
direction it would be on your DVR and you would have to have a
reference, like unreasonable sequence, to tell the difference. TV and
film motion is "perception" from still pictures.

Now I wonder too. It used to be common, especially in westerns. I
can't recall seeing an example from other than old films.

Wagon wheels are large with a very visible pattern. Car hub caps are
small and don't have near as much pattern, if any. And anyone who shoots
now should be aware of the effect so they can avoid it. I have seen
modern car commercials with the wheels going backwards, or forwards at
the wrong speed. And I suspect we are aware of the effect and ignore it.


Once again... The film frame rate was different than the 60 cycle
timing used as the basis for television video. If something is
recorded originally on video rather than film, it won't exhibit the
effect, because the original recording will have used the same 60
cycle standard as the TV used to reproduce it.

The reason it used to be more common is that today, less TV production
work is done using photographic film as the media.

It can certainly be picked up in video recording. If a wagon wheel is
rotating clockwise and the 1st frame/field has a spoke at 12:00, the
next frame has a spoke at 11:30, the next frame has a spoke at 11:00...
the wheel will appear to go backwards. You are not viewing a rotating
wagon wheel. You are viewing a series of still pictures that are
perceived as rotation. It is a strobe effect.

--
bud--

wrote in message
...
On Fri, 17 Jul 2009 08:14:20 -0700, "charlie"
wrote:


"Smitty Two" wrote in message
news
In article
,
DerbyDad03 wrote:

On Jul 16, 12:57 pm, Smitty Two wrote:
In article
,

DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

Ah, sorry, I'm DVR impaired.


That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... seems we're down to you, me, and harry on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.

if you look at video camera specs, they all have a "shutter speed" even
though there is no real shutter. that's the rate the computer can poll the
video chip, as it has to poll almost every location at very close to the
same time or you'd get smearing of the video picture.

thus, a video or film camera would still show the same phenomon of
strobing
on rotating parts.

regards,
charlie
cave creek, az


Incorrect.

The strobing on rotating parts is visible due to the difference in
frame rate (shutter speed) and the timing standard frequency of the
video equipment. IOW film played back on a TV set.

please reread for comprehension. you basically restated what i said. the
question was whether a video camera rather than a film camera would cause
the problem, and the answer is yes, as they both have "shutters"

wrote in message
...
On Fri, 17 Jul 2009 08:41:04 -0700, "charlie"
wrote:


wrote in message
. ..
On Fri, 17 Jul 2009 08:14:20 -0700, "charlie"
wrote:


"Smitty Two" wrote in message
news In article
,
DerbyDad03 wrote:

On Jul 16, 12:57 pm, Smitty Two wrote:
In article
,

DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to
post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not
record
the show.

Ah, sorry, I'm DVR impaired.


That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in
all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... seems we're down to you, me, and harry
on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.

if you look at video camera specs, they all have a "shutter speed" even
though there is no real shutter. that's the rate the computer can poll
the
video chip, as it has to poll almost every location at very close to the
same time or you'd get smearing of the video picture.

thus, a video or film camera would still show the same phenomon of
strobing
on rotating parts.

regards,
charlie
cave creek, az


Incorrect.

The strobing on rotating parts is visible due to the difference in
frame rate (shutter speed) and the timing standard frequency of the
video equipment. IOW film played back on a TV set.

please reread for comprehension. you basically restated what i said. the
question was whether a video camera rather than a film camera would cause
the problem, and the answer is yes, as they both have "shutters"


No, you are missing a vital piece of the puzzle. All faux shutter
speeds in a video camera are based on the 60 cycle standard. Film
cameras do not use that standard for shutter speeds.

If you use a film camera to film the screen of a TV, the screen on the
TV will appear to roll for this reason.

why would a digital video camera, running on dc internally, have a standard
based on 60 cycles?

http://www.mediacollege.com/video/camera/shutter/
http://www.videomaker.com/article/10418/

in reality, it doesn't. typical video shutter speeds are between 1/1000 to
1/2000 second.

the display on a tv is based upon 1/2 of the ac line current. that has
nothing to do with the shutter speed of the camera.

On Jul 17, 11:00*am, Smitty Two wrote:
In article
,





*DerbyDad03 wrote:
On Jul 16, 12:57*pm, Smitty Two wrote:
In article
,

*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

Ah, sorry, I'm DVR impaired.



That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... *seems we're down to you, me, and harry on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.- Hide quoted text -

- Show quoted text -

seems we're down to you, me, and harry on this one

Except that Charlie has now joined the discussion! g

In any case, I'm gonna step out 'cuz I'm going on vacation next week
and won't have too much access to a computer.

It was fun getting this thread started and I'll catch up when I get
back.

On Jul 17, 8:24*am, bud-- wrote:
wrote:
On Thu, 16 Jul 2009 20:27:23 -0700 (PDT), harry k
wrote:

On Jul 16, 11:26 am, DerbyDad03 wrote:
On Jul 16, 12:57 pm, Smitty Two wrote:

In article
,
*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.
snip
when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.
Step up to the plate in the name of science, and be the first to post
your clip online.
I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

If it is "wagon wheel" effect it would be on your DVR. If it were mirror
image it would be on your DVR and you would have to have a reference,
like text, to tell the difference. If it were video played in reverse
direction it would be on your DVR and you would have to have a
reference, like unreasonable sequence, to tell the difference. TV and
film motion is "perception" from still pictures.

Now I wonder too. *It used to be common, especially in westerns. *I
can't recall seeing an example from other than old films.

Wagon wheels are large with a very visible pattern. Car hub caps are
small and don't have near as much pattern, if any. And anyone who shoots
now should be aware of the effect so they can avoid it. I have seen
modern car commercials with the wheels going backwards, or forwards at
the wrong speed. And I suspect we are aware of the effect and ignore it.

Once again... The film frame rate was different than the 60 cycle
timing used as the basis for television video. If something is
recorded originally on video rather than film, it won't exhibit the
effect, because the original recording will have used the same 60
cycle standard as the TV used to reproduce it.

The reason it used to be more common is that today, less TV production
work is done using photographic film as the media.

It can certainly be picked up in video recording. If a wagon wheel is
rotating clockwise and the 1st frame/field has a spoke at 12:00, the
next frame has a spoke at 11:30, the next frame has a spoke at 11:00...
the wheel will appear to go backwards. You are not viewing a rotating
wagon wheel. You are viewing a series of still pictures that are
perceived as rotation. It is a strobe effect.

--
bud--- Hide quoted text -

- Show quoted text -

Exactly! Some of thed posters seem to think they are view 'moving
pictures' rather than a series of still shots.

Harry K

On Jul 17, 8:14*am, "charlie" wrote:
"Smitty Two" wrote in message

news




In article
,
DerbyDad03 wrote:

On Jul 16, 12:57 pm, Smitty Two wrote:
In article
,

DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.

snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.

Step up to the plate in the name of science, and be the first to post
your clip online.

I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

Ah, sorry, I'm DVR impaired.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... *seems we're down to you, me, and harry on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.

if you look at video camera specs, they all have a "shutter speed" even
though there is no real shutter. that's the rate the computer can poll the
video chip, as it has to poll almost every location at very close to the
same time or you'd get smearing of the video picture.

thus, a video or film camera would still show the same phenomon of strobing
on rotating parts.

regards,
charlie
cave creek, az- Hide quoted text -

- Show quoted text -

Thanks, I was wonderig about the video "shutter".

Harry K

On Jul 17, 7:53*am, Smitty Two wrote:
In article
,
*harry k wrote:

The number of each feature doesn't matter. *Look at a bicycle wheel
again. *Many spokes (one would do) but only 1 valve stem. * The drill
and all parts are all turning the same *rpm . *The features all appear
at the same time because they all come around together. * The ones
being illuminated *repeat all at the same repetition rate, I have been
puzzling all day how to explain that better but can't come up with a
way.

Of course the number of features matter. This is the way the illusion
works:

In your mind, superimpose a four-spoke wheel on a clock face, with
spokes pointing to 12,3,6, and 9. Label the spokes A,B,C, and D,
respectively.

Now, turn the wheel clockwise. Let's say you turn it 1/6 revolution,
a.k.a. 60 degrees, a.k.a. "two hours" of rotation. So A is pointing to
2, B to 5, C to 8, and D to 11.

But during the rotation, turn off the light, close your eyes, whatever.
Now what happens in the mind is that it misinterprets what the eye sees.
It makes more sense to the mind that the spokes have each moved
backwards one hour, rather than forwards two hours.

So you think that A moved from 12 to 11, rather than from 12 to 2. Of
course, it isn't A that you're seeing at 11, it's D. But A and D look
the same, because they're identical spokes.

The mind wants to believe that while the lights were out, things moved
as little as possible. So it sees the rotation slowly in reverse, rather
than more quickly in forwards.

Now superimpose another set of different features, but say there's six
of them instead of four. Call them A2, B2, C2, D2, E2, F2. Now with each *
60 degree rotational increment, each of those features also moves "two
hours." But they were already at 2 hour increments from one another (as
opposed to 3 hour increments for the 4-feature set.) So now, A2 takes
the exact place of B2, B2 takes the place of C2, etc. Result is that
this feature set will appear to stand still.

Finally let's look at a ten feature set, A3 through J3. Now they don't
all start out lined up with clockface numerals. A3 is lined up with 12
o'clock, and F3 is lined up with 6 o'clock, but the rest of them are
some fractional hours. So it will be easier to consider degrees of
rotation instead of clock readings.

360 degrees / 10 = 36 degrees. The last "spoke" (J3) in this feature set
is located at 360 - 36 = 324 degrees. After one 60 degree incremental
movement, A3 will be at 60 degrees, and J3 will be at 24 degrees. The
mind wants to see minimal change of position, so it now sees J3 as A3,
and believes that the wheel is rotating slowly clockwise (24 degrees per
increment instead of 60)

So, if you've followed this along, I hope you can see that the number of
features is critical to whether the mind sees forward motion, backward
motion, or a standstill, and that the apparent motion, either forwards
of backwards, is also slower than what's actually happening.

In the commercial, the different parts of the drill have different
numbers of features, so can't exhibit the same illusion at the same RPM.

I repeat. Teh strobe takes a "still picture" not a moving picture.
If it is timed to show reverse rotation then the same features _all_
of them visible will be in the right location each time the strobe
fires.

You can keep fighting it but you are wrong. Visit your local HS and
talke to the physics teacher, I have resorted to that in the past and
found out I was wrong on a point once.

Harry K

In article
,
harry k wrote:


I repeat. Teh strobe takes a "still picture" not a moving picture.

Exactly.


You can keep fighting it but you are wrong.

Sorry, but I'm sure you either didn't read my post, or didn't comprehend
it. I admit it's lengthy and a bit tedious to think through, but it
accurately explains the phenomenon, and details why the number of
features does matter.

But I really am done with this one now. Let us know if you ever actually
see the commercial.

charlie wrote:
wrote in message
...
On Fri, 17 Jul 2009 08:41:04 -0700, "charlie"
wrote:

wrote in message
...
On Fri, 17 Jul 2009 08:14:20 -0700, "charlie"
wrote:

"Smitty Two" wrote in message
news In article
,
DerbyDad03 wrote:

On Jul 16, 12:57 pm, Smitty Two wrote:
In article
,

DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.
snip

when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.
Step up to the plate in the name of science, and be the first to
post
your clip online.
I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not
record
the show.
Ah, sorry, I'm DVR impaired.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in
all
cases?
I'm not sure that I understand your question, and I'm not sure that I
could answer it if I did ... seems we're down to you, me, and harry
on
this one so we'll see whether we all have enough interest in the topic
to keep ferreting things out.
if you look at video camera specs, they all have a "shutter speed" even
though there is no real shutter. that's the rate the computer can poll
the
video chip, as it has to poll almost every location at very close to the
same time or you'd get smearing of the video picture.

thus, a video or film camera would still show the same phenomon of
strobing
on rotating parts.

regards,
charlie
cave creek, az

Incorrect.

The strobing on rotating parts is visible due to the difference in
frame rate (shutter speed) and the timing standard frequency of the
video equipment. IOW film played back on a TV set.
please reread for comprehension. you basically restated what i said. the
question was whether a video camera rather than a film camera would cause
the problem, and the answer is yes, as they both have "shutters"

No, you are missing a vital piece of the puzzle. All faux shutter
speeds in a video camera are based on the 60 cycle standard. Film
cameras do not use that standard for shutter speeds.

If you use a film camera to film the screen of a TV, the screen on the
TV will appear to roll for this reason.

why would a digital video camera, running on dc internally, have a standard
based on 60 cycles?

http://www.mediacollege.com/video/camera/shutter/
http://www.videomaker.com/article/10418/

in reality, it doesn't. typical video shutter speeds are between 1/1000 to
1/2000 second.

the display on a tv is based upon 1/2 of the ac line current. that has
nothing to do with the shutter speed of the camera.

salty is talking about frame rate. It is a few posts above - "frame rate
(shutter speed)". The frame rate is standardized at 60Hz.

(Actually I am not sure for digital TV. Analog TV had a frame rate of 30
per sec - near the film frame rate of 24 per sec - and a 1/2 frame
interlaced line field rate of 60 per sec.)

--
bud--


--
bud--

On Jul 17, 10:36*pm, Smitty Two wrote:
In article
,
*harry k wrote:



I repeat. *Teh strobe takes a "still picture" not a moving picture.

Exactly.



You can keep fighting it but you are wrong. *

Sorry, but I'm sure you either didn't read my post, or didn't comprehend
it. I admit it's lengthy and a bit tedious to think through, but it
accurately explains the phenomenon, and details why the number of
features does matter.

But I really am done with this one now. Let us know if you ever actually
see the commercial.

Okay, one last (I hope) try.

Mentally draw a line through the screw, the flat of the bit, the chuck
'finger'. Snap - one frame. Advance to the next frame and you will
see the same line through the same flat and the same 'finger' just
advanced a bit. Next frame and you get the same thing. You are seeing
the _same_ features just advanced a bit each frame.

Using your logic, the 'wheel effect' is impossible as there are always
more than one feature.

Harry K

harry k wrote:

-snip-
I went googling for the commercial. I'm not very good at specifying
search words. Found lots of hits, but no videos.


I'm pretty good at finding stuff. No luck. I even recorded 3
hours of Ice Road Truckers yesterday so I could scan through and find
the commercial. Not a single Craftsman commercial in the bunch. [I
was weird fast forwarding through the show to see the commercials.
Thought it was superbowl sunday all over again]

If anyone knows where the video of that commercial might be-- or
another Craftsman supported show- please post.

Jim

Download yahoo video,download google video,download dailymotion
video,download google video easy with this tool named Wondershare
Streaming Video Recorder.

More Info:
http://www.download-streaming-video....video.html#137
http://www.download-streaming-video....ideos.html#137
http://www.download-streaming-video....video.html#137
http://www.download-streaming-video....video.html#137
http://www.download-streaming-video....video.html#137

In article ,
stan wrote:
On Jul 13, 11:22*am, DerbyDad03 wrote:
On Jul 13, 8:16*am, "Colbyt" wrote:





"DerbyDad03" wrote in message

...

I was watching Ice Road Truckers last night, which is sponsored by
Craftsman, so they kept running this commercial for one of their
cordless tool lines.

They show one clip where the guy is drilling into a piece of wood
attached to a tree - steps to a tree house maybe - with a wood boring
bit. Maybe it was an optical illusion, but I'd swear the drill is
running backwards - *counter clockwise. I rewound my DVR a bunch of
times, and ran it it slow motion. It sure looked to me like the bottom
of the bit was coming up and the 3/8" marking was going away from, not
coming towards the viewer.

Has anybody else seen this?

If you watch TV films closely you can see the same thing with cars wheels in
close-ups.
I recall seeing this a lot on the old Bonanza TV series with the wagon
wheels.

It is a function of the filming process.The *film image is a mirror image of
the actual event.

--
Colbyt
Please come visit *www.househomerepair.com

The *film image is a mirror image of the actual event.

Then why isn't *everything*, including any text, backwards?- Hide quoted text -

- Show quoted text -

That's a digression.
.
What we have been discussing is 'timing'; as each part of something
rotating (in the case of wheels it could be identical-looking spokes
for example) comes into each frame of a film or TV picture. It may
then appear to be ahead of or behind the one seen in the preceding
frame. So the item my 'appear' to rotate either forwards or backwards.

Mirror or not; viewing film is a matter of the optics used and how the
film is then projected onto either a screen or into a TV transmitter.

It was possible in some film installations, for example, to adjust the
focal length etc. of the projector so that the picture could be seen
reversed and/or perhaps upside down!

WHAT IN THE WORLD ARE YOU TALKING ABOUT!?

(Hmmm. The date -- nope, not 1apr09.)

Either one early suggestion is what's happening, he's coming OUT of
the hole (or maybe he's just TESTING the gears in the drill?, or
even knowing it'll be on a tv series, watched by people from HERE,
sabototaging us by planting a flame-war seed?), or it's that
old cowboy-movie-effect of wagon-wheels APPEARING to be turning
BACKWARDS (while in full flight from the indians).

Easy demonstration. Look at the TV.

Now, either spread out your fingers and WITH ALL POSSIBLE SPEED
wave your hand back and forth between your eyes and the tv.

Better, put a FAN between you and the tv, and look THROUGH
the fan at the tv.

Better yet, no tv, put TWO fans together, and through both
look out the window or somewhere bright enough -- unless the
fans are going at the EXACT same speed (in which case you're
looking at ONE fan with WIDER blades), you'll see a slow
movement of an "artifact" (someone please say it with a bit more
care and accuracy) invented (as is everything visual, I guess)
by your brain.

Or, get two not-so-well-tuned pianos and simultaneously hit the same key
on each. Here that warbling sound? Similar effect. Maybe. Maybe
I've gone way too far off on a tanget from wagon-wheels.

Someone can surely improve on what I'm saying.

David

In article ,
Jim Elbrecht wrote:

because the screw kept going in.

AH HA!


David

In article ,
stan wrote:
On Jul 13, 10:49*am, The Daring Dufas
wrote:
DerbyDad03 wrote:
I was watching Ice Road Truckers last night, which is sponsored by
Craftsman, so they kept running this commercial for one of their
cordless tool lines.

They show one clip where the guy is drilling into a piece of wood
attached to a tree - steps to a tree house maybe - with a wood boring
bit. Maybe it was an optical illusion, but I'd swear the drill is
running backwards - *counter clockwise. I rewound my DVR a bunch of
times, and ran it it slow motion. It sure looked to me like the bottom
of the bit was coming up and the 3/8" marking was going away from, not
coming towards the viewer.

Has anybody else seen this?

Did you consider the fact that the guy is an actor.
The drill may actually be turning backwards because
the actors and directors don't have a clue. I know,
I'm being fecesious (sic).

TDD

Yup facetious. Happens often with films and TV because the picture we
see is actually some 25 to 30 snapshots (or frames) per second.
For example, with TV, older TV anyway not necessarily digital and HD,
it it is presented to us so that alternate lines are scanned and
viewed first each frame and then during the same frame it goes back
and does the intervening lines.
In fact any thing rotating may appear to be either going forwards or
backwards. Doesn't mean a thing.
But maybe the hole had been drilled by the fifth take and they are now
on their 15th and the actor is basically instructed to "Here; hold
this and pretend you are drilling. And oh, by the way look happy about
it ......"! :-)

NOW we're talkin!

David

In article ,
Larry The Snake Guy wrote:
On Jul 13, 11:35*am, Smitty Two wrote:
In article
I've read the respondents thus far who attribute it to the wagon wheel
effect, and I don't think that's what's going on at all. The wagon wheel
effect happens in real life, not just TV, so it isn't a "frames per
second" issue.

Well, ,it's a frames-per-second issue SOMEWHERE.

Hmmm. Agent Orange, maybe? Nerve-gas in Iraq? Some delayed
effect from DU dust?

Very, very sorry, friend (PRIOR poster to snake guy), but your
nervous system may be crapping-out -- and THAT's where the
intermittent (sp?) visual transmission is coming from. :-(

(All in jest, I hope I'm being taken.)

BUT -- sure as hell, if you'd gone to the VA to have it checked,
Bush & Co. would have closed that hospital as soon as you
arrived -- and the next one too, and also the one after that.

But that's a whole other EXTREMELY depressing subject. Aboout
the "patriots" we elect to rule us.

David

In article ,
Smitty Two wrote:
In article
,
DerbyDad03 wrote:

What possible advantage would it be for the editor or layout person to
"flip" the drill direction around?

The reversal of the drill direction would be an *unintended* consequence
of reversing the picture so that, for example, the person is on the left
and the drill is on the right.

I've got the answer!


It was done in the U.K.!


g

David

In article ,
harry k wrote:
On Jul 16, 9:34*am, Smitty Two wrote:
In article
,
*harry k wrote:





On Jul 15, 9:42*pm, Smitty Two wrote:
In article
,
*harry k wrote:

....

I wonder if there is a cheap strobe light out there. They were fun to
play with back in HS physics.

Shine a bright light-BEAM, in a DARK ROOM, through a fan, and have someone
swing a yo-yo or something in a circle -- and vary the yoyo-speed,
and the fan-speed.

MAYBE the effect will show up.


AH! Or have the through-the-fan light-beam shine on ANOTHER fan!

Try them BOTH.


(Dog chasing tail?)


David

In article ,
bud-- wrote:
....
....

salty is talking about frame rate. It is a few posts above - "frame rate
(shutter speed)". ...

I know you don't mean that, just mis-written.

The SHUTTER-SPEED is how LONG the shutter STAYS OPEN for a SINGLE picture.

If you take only one picture a year, your FRAME-RATE -- well, photo-taking
rate, maybe -- is ONE per YEAR, the "dimensional units" of that being
"photos / amount-of-time-taken-by-your-photo-taking", something like that.

A movie or video photographed or "taken" as above would be in VERY "SLOW-MOTION".

(That is, if you VIEWED it at eg 50 or 60 or whatever frames (pictures) per
second.)

Shutter-speed describes a SINGLE picture or frame -- if there's 5000
pictures or frames to be shown rapidly, one after the other, that
shutter-speed describes EACH SINGLE ONE (presumably).

Frame-rate is "independent" of (some say "orthogonal to") that --
hey, I'm out of words, what else can I say, huh?

David

David Combs wrote:
In article ,
bud-- wrote:
...
...
salty is talking about frame rate. It is a few posts above - "frame rate
(shutter speed)". ...

I know you don't mean that, just mis-written.

Of course I mean it.

salty said "All faux shutter speeds in a video camera are based on the
60 cycle standard." charlie said *shutter speeds* are not based on 60
cycles, which is correct. But salty is clearly referring to a *frame
rate*, which is based on "the 60 cycle standard".

The SHUTTER-SPEED is how LONG the shutter STAYS OPEN for a SINGLE picture.

If you take only one picture a year, your FRAME-RATE -- well, photo-taking
rate, maybe -- is ONE per YEAR, the "dimensional units" of that being
"photos / amount-of-time-taken-by-your-photo-taking", something like that.

A movie or video photographed or "taken" as above would be in VERY "SLOW-MOTION".

(That is, if you VIEWED it at eg 50 or 60 or whatever frames (pictures) per
second.)

Shutter-speed describes a SINGLE picture or frame -- if there's 5000
pictures or frames to be shown rapidly, one after the other, that
shutter-speed describes EACH SINGLE ONE (presumably).

Frame-rate is "independent" of (some say "orthogonal to") that --
hey, I'm out of words, what else can I say, huh?

Most of us know all that.

--
bud--