Talk:Gamut

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Template:WikiProject Color

Digital cameras

Gutza, your contribution about digital cameras and dynamic range looks like a valuable information for people interested in photography, but I'm not convinced that it actually belongs in a page about "gamut".

I'm not that much of an expert in photography terminology (I do know a bit about how cameras and CCDs work, though), but I think your discussion about "dynamic range" is about the range between the black point and the white point. Gamut refers to the shape of the area perpendendicular to that line. I agree with you that megapixel counts on digicams are misleading since typically 1/2 of the pixels represents green, and 1/4 red and blue, but that has absolutely nothing to do with the color reproduction. You mention uniformity in recording all colors in the spectrum at a given brightness.. Don't know what you mean, but gamut refers to how colors are reproduced, not whether they are recorded. If you photograph violet light (400 nm) with a film, the print will not look violet. Also, different brands/types of film have different behaviour in color reproduction, some being better for human skin colors, others better for use under fluorescent lighting. That implies that different films have different gamuts.

Your text is also a bit non-NPOV, with words such as "honest", "cheat", and "satisfy sale characteristics".

Han-Kwang (talk) 12:45, 20 May 2004 (UTC)

Hi Hankwang,

Sorry for the way-late reply, see my user page for details. For an explanation of my apparent POV, please see this page (http://nfg.2y.net/games/ntsc/visual.shtm). Both streaming video encoding systems and digital camera manufacturers "cheat" with their products by encoding as little red and blue information in their resulting output as necessary to be unnoticeable. Film doesn't do this. Check it out with your own digital camera, take a random photo, zoom in to 200% and look at each discrete channel if your software supports this -- you'll see what I mean. This is not meant to be POV, it's the only wording I could find -- and they are cheating, because no camera manual will tell you this, yet they all do it and everybody in the business knows they're doing it. What would you call that? Anyway, if you find a milder wording which does convey the meaning of what I'm babbling in this paragraph, by all means, be bold! :) --Gutza 12:04, 30 Aug 2004 (UTC)

P.S. You might be right about the dynamic range issue, I'll try to look into that if I have the time. Please do fix it if you know for a fact that only brightness is what is meant by dynamic tange in film. --Gutza 12:10, 30 Aug 2004 (UTC)

Relative Sizes of Gamuts

I'ld like to see some references for the claims made in the article about which types of display systems have the largest gamuts. I not convinced that the gamut for a laser based system would be larger than that of a CRT. It may be, but it seems to me that unless a number of lasers of different colors are used, the problem with a tringular shaped gamut would still remain.

I wasn't too happy with the comparisons either, but I will observe that the area which can be covered by a triangular gamut varies depending on two factors: The saturation of the three primaries chosen (so, distance from the central white on the chromaticity chart) and the particular wavelength of the three primaries (so, positions along the edge of the chromaticity chart). In theory, a laser-based three-primary system should be able to achieve the largest gamut because, unlike chemical phosphors on a CRT screen, the lasers are always fully-saturated (because they can be truly monochromatic) and the wavelengths can be chosen pretty-much arbitrarily. As far as I know, you can't choose phosphor wavelengths arbitrarily while maintaining full saturation. I don't know how well this theory plays out in practice.

(And, of course, systems with more than three primaries can cover much larger gamuts, but I don't think there's any disagreement over that! :-) )

Atlant 14:19, 10 Mar 2005 (UTC)

Gamut and syntheticable colors

I don't understand all that discussion about gamuts: my eyes have three different sensors for red, green and blue. Therefore, the only thing my TV/LCD screen/etc needs are subpixels with the colors red, green and blue to make me happy (= give me all colors I am able to see).

As i'm limited to these three sensors, it should be of no importance what spectrum my LCD backlight emits, as long as I get red, green and blue colored light beams to my eyes. Also, my CRT/LCD screen should be able to represent all the colors you (=human person) can see in real nature, as (you already suspect it) you can see only a mixture of the colors red, green and blue.

who cares about the adding of an additional cyan subpixel in a TV, as I don't have a sensor in my eyes to exclusively see this color. I have green- and blue-sensors in my eyes to do this job. And therefore cyan should be obsolete, as the green and blue subpixel in the TV can already fake this color.

in a nutshell: please explain, why gamuts and/or gamut enhancements are important - i won't see the additional colors anyways, or will I? A bigger gamut will not give me more colors than a smaller gamut that already covers RGB.

thank you so much! --Abdull 18:49, 19 Mar 2005 (UTC)