Talk:Colour reproduction

Although demonstrated by every printed or projected colour reproduction, it remains a theory that cannot be proven.

What kind of proof is lacking? This is a provocative statement, whose meaning is not explained. What is the source of this assertion? Surely the spectral response of the cone cells is known. And the practical application of that knowledge is the basis of numerous technologies outside photography (fluorescent lighting, LCD displays). ( --Vox 06:40, 13 February 2012 (PST)

Isn't the Young-Helmholtz stuff from the 1800s? A quick google suggests it was replaced after the late 1950s with work done by Hurvich and Jameson that showed trichromatic theories had essentially been describing how human retinal processing works (as opposed to a phenomenon in the outside world).Steevithak 09:20, 13 February 2012 (PST)

Lots of scientists wrote about colors. A look into Wikipedia makes us knowing than J.C. Maxwell's writings of 1860 might be the right to mention in this topic, but you can't be sure: Helmholtz, Graßmann, Maxwell, Goethe (?). U. Kulick 07:21, 14 February 2012 (PST)

What's up the color-related glossary entries? Looks like several have been deleted and moved to this shared page. I thought the idea with the glossary was to have concise definitions of words rather than elaborate articles. I wasn't around back when the glossary idea was added, so I could be wrong here. It seems like this is more of an attempt to duplicate Wikipedia's more in-depth articles on Color and color space (in which case is should probably be named "color space" or "color theory" rather than "three color theory". Also some references would be good. In general we're trying to move toward more reliable articles and proper citations are an important part of that. Anyway, not objecting; just asking for some illumination on the plan. Steevithak 09:20, 13 February 2012 (PST)

Also watch the localized spelling. In general we favor "color" vs "colour" by about a 3 to 1 ratio in articles. But as long as which ever variant you use is internally consistent within the article that's okay. So no worries if you really want to use "colour" in a new article you're writing but we don't want to start changing existing articles from one to other. Steevithak 09:20, 13 February 2012 (PST)

Yes In general it is a good idea to be aware of what already exists in the wiki, before attempting to make additions. There is already a bit of discussion in the article Film about its layers with different color sensitivity. When you do make additions, appropriate cross-links between wiki articles should be included. Except in trivial cases, wiki articles should not be deleted until you've put some explanation on the article talk pages describing what you think the problem is, and how you propose to solve it. --Vox 10:14, 13 February 2012 (PST)

Hello and thank you for the discussion, always welcome! Yes, the Young-Helmholtz theory dates from the 1800s: the 19th century. Stating the public fact that it remains theory shouldn't be provocative, relativity remains a theory even though it has more supporting evidence than any theory in history apart from quantum physics, which is also theory that happens to be supported by every electronic device. Evidence alone proves nothing.

OK, I take the blame for moving several glossary entries here and true it has become an article so maybe it should be spun off. I have not deleted any material, merely merged some rather short and (to me) incomplete entries.

Some suggestions, please. Maybe RGB and CMY should be restored to the glossary and this article moved to the general arena DesmondW 13:24, 13 February 2012 (PST)

PS - if this article is to be moved then I suggest "Colour reproduction" as the title DesmondW 13:27, 13 February 2012 (PST)

Generally the purpose of glossary entries is to define terms which are used frequently in our other articles, but which may be unfamiliar to someone new to photography. Thus when selenium meter or reflex finder appear in other pages, the words link to explanations of those terms. Also, glossary items are indexed alphabetically including a one-sentence summary—which in some cases gives all the information necessary (e.g. spelling out acronyms). This was a reason for RGB and CYMK to have brief entries, although I doubt many articles linked to them.

The likelihood seems low of any camera description linking to "Three color theory," or of a reader stumbling across this term and seeking its definition. It may be possible that as a basic science topic we might discuss it; but I agree with Steevithak there is little purpose in trying to outdo the existing, extensive, well-sourced articles already found in Wikipedia. The only justification would be if the topic could be made much more directly relevant to photography (e.g. discussing Bayer filters). --Vox 15:21, 13 February 2012 (PST)

On the topic of what counts as a provable theory, we are not "epistemology-wiki.org." Most readers would take your statement as one that casts doubt on the validity of the theory. On what basis?--Vox 15:27, 13 February 2012 (PST)

On the basis that it cannot be proven mathematically or by other techniques, it can only be demonstrated empirically. This is open knowledge, not opinion, but I have removed the remark DesmondW 08:50, 14 February 2012 (PST)

Clarity? Sources? Purpose?

At the moment this article is veering off course rather worryingly. Before adding anything more to it, please consider the following:

• What aspects of color theory are actually relevant to photographers or camera collectors? (Our wiki does not exist to be tutorial in basic science—especially if the material is better-explained elsewhere)

• Can you cite sources for your statements?

• Is the article understandable?

--Vox 12:43, 14 February 2012 (PST)

Seconded. More material is busily being added, for no obvious reason, and with no authoritative source provided. -- Hoarier 17:26, 14 February 2012 (PST)

To me his article fulfils a very useful middle ground explaining color (sic) reproduction as it applies to photography (the human eye section is perhaps redundant). If you don't like it then remove it, most of the material is general knowledge and doesn't necessarily need explicit sources DesmondW 08:44, 18 February 2012 (PST)

Every article is improved and made more authoritative if its sources are explicit. This is simply a matter of preserving accountability, and avoiding disputes over questionable assertions. For example the article now states "most amateur enlargers are marked RGB" which is puzzling and demonstrably wrong. Or, "James Clerk Maxwell demonstrated in 1855 that all colours can be reproduced by mixtures of three primary colours." This is not a fact photographers walk around carrying in their heads—I feel quite certain someone needed to look this up. Fine, but where? If it comes from Wikipedia, please remember WP is also compiled by a bunch of well-meaning, but amateur volunteers. Likewise if it comes from some enthusiast website. Without citing some source (a period scientific journal, or a respected biography of Maxwell) how will anyone know if it is trustworthy? --Vox 13:04, 20 February 2012 (PST)

I am getting thoroughly fed up of the "thought police" who seem to patrol this site, making unwelcome alterations to articles, adding unnecessary tags, and complaining about content. The simple fact that others have contributed and the page is receiving visitors is demonstration of interest in the topic.

I stated "most amateur colour enlargers are marked RGB" which is from decades of experience working in the industry; you cite one example and contentiously state "demonstrably wrong". Nonsense; make proper references.

References for the very well known three colour theory abound, you can find many yourself. DesmondW 08:40, 21 February 2012 (PST)

When I said that the reference to RGB enlarger markings was "puzzling," let me expand on that. If a color enlarger is designed to make a single exposure with white light passing through color-correcting filters, these must be the subtractive primaries, CMY. I have a color-printing filter pack in my basement; I can assure you this is a graduated set of CMY filters. Thus, one would expect to see enlarger dials with calibrated CMY values. Besides the Beseler enlarger I cited, we see this in models from Omega, Vivitar (PDF page 16), and Minolta (5th paragraph of 1981 review, reproduced at bottom). I see in this Philips enlarger manual dated 1981, that its controls indicate CMY and RGB complementaries on its dials; but it also makes the comment "at this time most books and literature are geared towards the subtractive print" (page 4) while noting that earlier practice was to make separate R, G, and B filtered exposures. Perhaps this is the source of our confusion.

On the wider topic of "thought police": As I mentioned to you very early on, a wiki is by its nature a collaborative project. This may not be to everyone's tastes. We at camera-wiki.org are too small to have any formal ranks, titles, or "reputation" system. But it is advisable to be aware of which contributors have voluntarily donated the greatest amount of their time and energy to our project. Naturally these people expect their advice and criticisms to be heard, and responded to in a cooperative spirit. We are all striving to make the wiki better—in some cases by tightening up content standards, which in the past were more lax. I am sorry if you find us excessively meddlesome, however I am afraid this will continue.--Vox 10:22, 21 February 2012 (PST)

Purely on references for Maxwell, and exactly what he said, I found a compilation of his papers at Internet Archive a while ago; I have bookmarked it, and mean (sometime...) to read the relevant ones; seem to be three or four of them, some concentrating on colour perception and colour-blindness, and others specifically about compound colours. The basic idea of colours being represented as combinations of three primary components he seems to attribute to Newton. I did note that in at least one of the papers he talks about red, green and violet, not blue (it's interesting (it is to me) that Autochrome used orange-red, green and violet-blue, not the primaries we are familiar with). The compilation isn't the most respectable reference; that would be the original papers, in the Transactions of the Royal Society of London (or Edinburgh, for at least one of them); but this compilation being accessible to anyone with internet trumps that, I think. I'll come back and add the refs when I've understood exactly what they do and don't say.

On getting fed up, I must second Vox: you can't afford to be offended if another wiki editor disputes the accuracy or the usefulness of what you've written, or criticises how it's written. It's ok to defend your work, but not to object to the discussion itself. I have learned quite a bit here when other writers corrected what I thought I knew to be true. The criticism is not meant to be an attack (even if some of us skipped the Internet Charm School - I know I did). --Dustin McAmera 14:01, 21 February 2012 (PST)

On one more minor point: The template "work in progress" {{WIP}} is one that editors often add to their own work, to indicate when additions and revisions are still ongoing. This alerts other editors that it may be wise to wait before diving in to make corrections. An example here from another editor illustrates.--Vox 18:38, 21 February 2012 (PST)