wrote:
Arfa Daily wrote:
"Geoffrey S. Mendelson" wrote in message
...
Arfa Daily wrote:

Well, I saw one of these LED backlit TV sets from Sammy in a store last
night, and I have to say that I was not particularly impressed with the
picture quality. Comparing to conventionally backlit (CCFL) Sony and
Panasonic offerings in immediate proximity to the Sammy, it was my opinion
that the rendition of skin tones, which we previously agreed was a good test
of a colour display's performance, was actually nothing like as good. Both
the Pan and the Sony had a near identical 'tone' to the skin of a
newsreader's face. On the Sammy, that same face was rather pink and florid
looking. I also did not think that the black level was any better than on
the other two sets, which is a point that they are making a lot of, claiming
that it substantially increases the contrast ratio.

I don't know what 'set-ups' this TV has, in terms of brightness, contrast,
colour saturation, tint/hue, but in my experience, most LCD TVs - which is,
after all, what this is - are set correctly 'out of the box', but I accept
that this particular one that I saw might not be a good example of the
technology.

I forgot to have a look round the back of it to see if there was a rating
plate, but next time I'm in that store, I will try to remember.

In the set's favour, it is very pretty-looking. The slimness of the display
is extremely impressive, and at this point in my evaluation, far outweighs
any display-quality aspects being claimed for it ...

Arfa


Based on the assumption that it is a PAL set probably brightness,
contrast, and maybe color saturation. Digital TV sets are not PAL per
se, but they still use the same luminance, color, sync, signals that are
used by PAL (and slightly differently by NTSC).

They are also still 25 or 30 frames per second depending upon whether or
not thay are interlaced as in 1080i or not. An interlaced frame is still
2 fields, at 50 or (almost 60Hz) combined.

The main differences between a digital TV signal and an analog one are
that
since each frame is discrete, there really is no need for a syncronization
pulse to define the begining of each frame and more importantly, there is
no color subcarrier.

If you were to look at a digital TV signal decoded as if it were a
stream of pixels, you would see something that looked a lot like an
analog TV signal.

Computer displays, BTW are red-green-blue with seperate horizontal and
vertical
sync, which is very different.


Geoff.

Yes Geoff, I'm aware of all that. I work with the technology all the time.
Did you read the original thread from last week ? We were not discussing the
differences between transport and encoding systems, rather the moral - if
not technical - validity of Sammy advertising this new offering of theirs as
a "LED TV", which it isn't. It's an LCD TV with an alternate form of
backlighting (LEDs rather than CCFL).

One of the main selling points that they claim, is that because they can
control the intensity of the backlighting in individual areas, they can
deepen the blacks, effectively improving the contrast ratio. On the example
that I saw last night, I observed no such improvement that was obvious,
compared to the sets around it. The reason that I questioned what controls
for picture setup are available on this particular set, was that given that
the backlighting is formed by RGB LED arrays, not white LEDs, then the
overall colour temperature would in theory be adjustable - sort of a grey
scale adjustment for LCDs, if you like. If this was the case, it might be
accessible to the customer via the standard controls menu, as something like
"tint" or "hue", and the reason that this particular set (they only had the
one on display) did not seem to produce good flesh tones compared to the
sets around it, might be because some sales erk had been playing with the
controls to see if he could 'improve' it ...

Someone - maybe William - commented last week in the original thread, that
they had seen one in Fry's in the U.S., and that they weren't especially
impressed, either.

Arfa

surely the flesh tones are entirely down to the colour settings, ie
background, drive, or hue, colour temp etc. Any 3 channel display
except early LCDs can do a palette including all the usual skin tones.

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..


NT

You would think so really, but going back to film photography,
there are reasons why portraits were always shot on eg, Konica,
landscapes on Agfa or Fuji, and no one used Kodak at all
professionally -- except for Kodachrome.

No one? Kodak sold -- and still sells -- professional color-negative film
that's often used for wedding photography. In fact, GYF recently introduced
an ultra-fine-grain professional color-negative film. If there weren't a
market for it...

I should tell you that, when I use color-negative film, it's Fuji. Part of
the reason is price, the other is that Costco uses Fuji paper. Fuji on Fuji
produces better results than Kodak on Fuji. (The opposite is also true.)

The Natural Philosopher wrote:
wrote:
Arfa Daily wrote:
"Geoffrey S. Mendelson" wrote in message
...
Arfa Daily wrote:

Well, I saw one of these LED backlit TV sets from Sammy in a store last
night, and I have to say that I was not particularly impressed with the
picture quality. Comparing to conventionally backlit (CCFL) Sony and
Panasonic offerings in immediate proximity to the Sammy, it was my opinion
that the rendition of skin tones, which we previously agreed was a good test
of a colour display's performance, was actually nothing like as good. Both
the Pan and the Sony had a near identical 'tone' to the skin of a
newsreader's face. On the Sammy, that same face was rather pink and florid
looking. I also did not think that the black level was any better than on
the other two sets, which is a point that they are making a lot of, claiming
that it substantially increases the contrast ratio.

I don't know what 'set-ups' this TV has, in terms of brightness, contrast,
colour saturation, tint/hue, but in my experience, most LCD TVs - which is,
after all, what this is - are set correctly 'out of the box', but I accept
that this particular one that I saw might not be a good example of the
technology.

I forgot to have a look round the back of it to see if there was a rating
plate, but next time I'm in that store, I will try to remember.

In the set's favour, it is very pretty-looking. The slimness of the display
is extremely impressive, and at this point in my evaluation, far outweighs
any display-quality aspects being claimed for it ...

Arfa


Based on the assumption that it is a PAL set probably brightness,
contrast, and maybe color saturation. Digital TV sets are not PAL per
se, but they still use the same luminance, color, sync, signals that are
used by PAL (and slightly differently by NTSC).

They are also still 25 or 30 frames per second depending upon whether or
not thay are interlaced as in 1080i or not. An interlaced frame is still
2 fields, at 50 or (almost 60Hz) combined.

The main differences between a digital TV signal and an analog one are
that
since each frame is discrete, there really is no need for a syncronization
pulse to define the begining of each frame and more importantly, there is
no color subcarrier.

If you were to look at a digital TV signal decoded as if it were a
stream of pixels, you would see something that looked a lot like an
analog TV signal.

Computer displays, BTW are red-green-blue with seperate horizontal and
vertical
sync, which is very different.


Geoff.

Yes Geoff, I'm aware of all that. I work with the technology all the time.
Did you read the original thread from last week ? We were not discussing the
differences between transport and encoding systems, rather the moral - if
not technical - validity of Sammy advertising this new offering of theirs as
a "LED TV", which it isn't. It's an LCD TV with an alternate form of
backlighting (LEDs rather than CCFL).

One of the main selling points that they claim, is that because they can
control the intensity of the backlighting in individual areas, they can
deepen the blacks, effectively improving the contrast ratio. On the example
that I saw last night, I observed no such improvement that was obvious,
compared to the sets around it. The reason that I questioned what controls
for picture setup are available on this particular set, was that given that
the backlighting is formed by RGB LED arrays, not white LEDs, then the
overall colour temperature would in theory be adjustable - sort of a grey
scale adjustment for LCDs, if you like. If this was the case, it might be
accessible to the customer via the standard controls menu, as something like
"tint" or "hue", and the reason that this particular set (they only had the
one on display) did not seem to produce good flesh tones compared to the
sets around it, might be because some sales erk had been playing with the
controls to see if he could 'improve' it ...

Someone - maybe William - commented last week in the original thread, that
they had seen one in Fry's in the U.S., and that they weren't especially
impressed, either.

Arfa

surely the flesh tones are entirely down to the colour settings, ie
background, drive, or hue, colour temp etc. Any 3 channel display
except early LCDs can do a palette including all the usual skin tones.

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..


NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.


NT

wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.


NT

"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only reflect
some portion of the spectrum of light it has absorbed.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under different
lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different brands of
film is not applicable at all.

HTH

Schrodinger's cat wrote:
"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only reflect
some portion of the spectrum of light it has absorbed.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under different
lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different brands of
film is not applicable at all.

HTH

issues very different.

wrote:
Schrodinger's cat wrote:
"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:
You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT
Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only reflect
some portion of the spectrum of light it has absorbed.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under different
lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different brands of
film is not applicable at all.

HTH

issues very different.
Proof by assertion.

The Natural Philosopher wrote:
wrote:
Schrodinger's cat wrote:
"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:
You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT
Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only reflect
some portion of the spectrum of light it has absorbed.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under different
lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different brands of
film is not applicable at all.

HTH

issues very different.
Proof by assertion.

I find it hard to believe that anyone could think the same controls
were available to them with a paper/transparency process as with a
computer monitor. I cant think of any possible motivation to prove
whats quite obvious to anyone's that done photographic printing.


NT

The Natural Philosopher wrote:
wrote:
Schrodinger's cat wrote:
"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:
You would think so really, but going back to film photography,
there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally -
Except for
Kodachrome..

NT
Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only
reflect
some portion of the spectrum of light it has absorbed.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under
different
lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different
brands of
film is not applicable at all.

HTH

issues very different.
Proof by assertion.

Go read some textbooks on the subject of colour management for screen &
print. The topic is far too complex to sum up from first principles in a
newsgroup post.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Schrodinger's cat wrote:


"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there
are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except
for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only
reflect some portion of the spectrum of light it has absorbed.

Color transparencies which are used in pro film applications say your
are a liar.

A screen is is sending transmitted light to your eye, which has no
reflective element to speak of.

Put even more simply, a printed image varies dramatically under
different lighting conditions, unlike a screen.

They could hardly be less identical and the analogy with different
brands of film is not applicable at all.

HTH

In article ,
The Natural Philosopher wrote:
A printed image is sending reflected light to your eye. It can only
reflect some portion of the spectrum of light it has absorbed.

Color transparencies which are used in pro film applications say your
are a liar.

The term printing was highjacked by photography and film - doesn't mean
the same as the original use. Which was transferring dyes from an
impression to paper, etc.

--
*Most people have more than the average number of legs*

Dave Plowman London SW
To e-mail, change noise into sound.

The Natural Philosopher wrote:

Color transparencies which are used in pro film applications say your
are a liar.

Not really. Transparencies subtract some colours from the transmitted
light; prints subtract some from the reflected light. Displays make
their own...

Andy

Andy Champ wrote:
The Natural Philosopher wrote:

Color transparencies which are used in pro film applications say your
are a liar.

Not really. Transparencies subtract some colours from the transmitted
light; prints subtract some from the reflected light. Displays make
their own...


Ah, so that is why they are backlit then?

So they can 'make their own?
What a prat. An LCD display IS a color transparency.

Andy

Andy Champ wrote:
The Natural Philosopher wrote:

Color transparencies which are used in pro film applications say your
are a liar.

Not really. Transparencies subtract some colours from the transmitted
light; prints subtract some from the reflected light. Displays make
their own...

And LCDs use a matrix of RGB filters over a backlight, which makes them
behave similarly to a transparency in a projector, with the exception
that you can tweak the RGB values to change the colour balance - which
you *can't* do with film transparencies.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

The Natural Philosopher wrote:
Schrodinger's cat wrote:


"The Natural Philosopher" wrote in message
...
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography,
there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally -
Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

No, they aren't.

Very basically, you have to understand that:

A printed image is sending reflected light to your eye. It can only
reflect some portion of the spectrum of light it has absorbed.

Color transparencies which are used in pro film applications say your
are a liar.

Colour transparencies aren't printed images.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

The Natural Philosopher wrote:
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

You can't tweak the colour response of film, you can with CRTs or LCDs.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

In article ,
Bob Larter wrote:
You can't tweak the colour response of film,

You can during processing.

--
*All those who believe in psychokinesis, raise my hand *

Dave Plowman London SW
To e-mail, change noise into sound.

You can during processing.

How? The film's color response is basically set by the choice of
sensitizers.

You can adjust the balance, but that's not the same thing.

Dave Plowman (News) wrote:
In article ,
Bob Larter wrote:
You can't tweak the colour response of film,

You can during processing.

Yeah, okay, you can, but it's rarely done.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Bob Larter wrote:
You can't tweak the colour response of film, you can with CRTs or LCDs.

People have been known to do it with Ektachrome type film (Ektachrome,
Fijuchrome, AgfaChrome, Ilfochrome, etc) with varying success by tweaking
the exposure and development.

At one time you could get Kodachrome developed to spec, which was
intended to correct for mistakes in exposure, but it certainly would
change color response.

In the printing process, either to film (used in movies) or paper, you
could do all sorts of things.

Standard C-41 color film has an exposure latitude of less than one stop
underexposure, but 4-5 stops of overexposure. As the exposure increases,
color response, contrast and graniness change. If you like fine grained over
saturated colors, try shooting a roll of ISO 100 color negative film and
have it processed normally.

Technicolor which is actually a black and white negative process (producing
seperate red, green and blue negatives on black and white film) could very
easily be manipulated and often was. Look at the recent prints (or the
DVD from them) of The Wizard of Oz.

The original intention was to produce a movie that was almost cartoon
like in its color, later prints were much more subdued, almost "normal"
in color as well as the video tapes made from them.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

Geoffrey S. Mendelson wrote:
Bob Larter wrote:
You can't tweak the colour response of film, you can with CRTs or LCDs.

People have been known to do it with Ektachrome type film (Ektachrome,
Fijuchrome, AgfaChrome, Ilfochrome, etc) with varying success by tweaking
the exposure and development.

That's true, but it's a joke compared to being able to directly tune the
black level & amptitude of RGB levels on an LCD panel or CRT.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Bob Larter wrote:
The Natural Philosopher wrote:
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography, there
are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally - Except
for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

You can't tweak the colour response of film, you can with CRTs or LCDs.

You can actually.

The Natural Philosopher wrote:
Bob Larter wrote:
The Natural Philosopher wrote:
wrote:
The Natural Philosopher wrote:

You would think so really, but going back to film photography,
there are
reasons why portraits were always shot on e.g. Konica, landscapes on
Agfa or Fuji, , and no one used Kodak at all professionally -
Except for
Kodachrome..

NT

Film is a whole nother business. You've got a lot less control over
its 'colour settings' than you have with a display screen, and ditto
re optical linearity. The issues with an LCD screen are quite
different.

well in the sense that they all use combinations of RGB (or CYMK) to
produce a 'full colour spectrum'and none succeed perfectly for all
applications, they are considerably identical, actually.

You can't tweak the colour response of film, you can with CRTs or LCDs.

You can actually.

Nothing like to the degree that you can with CRTs or LCDs.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------