Talk:Photographic paper

message: Hey guys, I just changed the page to use the spelling of color with a "u" (colour). I did this as it was overall more common in the article (18 appearences vs 10), and have added the appropriate tag on the talk page. Feel free the change it to american if you feel that would be more appropriate, but either way the standerdisation was required.Xevus11 (talk) 05:58, 29 December 2016 (UTC)
thread_title: Spelling of Colo(u)r

message: An anonymous user added a comment claiming that this paragraph was not true (I reverted it):
:Photographic emulsions are also produced in a variable contrast type which permits the selection of any grade between 00 and 5. Variable contrast photographic paper is actually coated with a mixture of two types of emulsion, one of which is very low in contrast (0 or 00) and one of which is very high in contrast (5). The low contrast layer is activated by green light, the high contrast layer by blue light. The use of filters activates each layer in different proportions, thereby creating all contrast grades from 0 (or 00) to 5.
My understanding of using coloured filters with B&W film or paper was that the emulsion reacts differently to the different wavelengths of light. So red reacts fastest, producing a higher-contrast image than orange, yellow, green, or blue. Can someone provide a correct (or at least better) description? --Imroy 08:00, 4 January 2007 (UTC)
replies: text: The description doesn't seem so far off. Silver bromide is naturally blue sensitive, with others added by sensitizing dyes. I am pretty sure, then, that the low contrast layer is also activated by blue light. But no, there is no part that relates to reaction time. A grain either is or isn't exposed and developed. It has no memory of the color of light that exposed it. There is some delay effect that leads to reciprocity failure, where exposure over too long or short a period gives different results, but not contrast related. Gah4 (talk) 21:51, 4 July 2013 (UTC)
thread_title:  Variable contrast papers 

message: What are the traditional photo sizes? Does it vary by country?  —Preceding unsigned comment added by 202.160.118.227 (talk) 10:14, 19 January 2008 (UTC)
thread_title:  Sizes 

message: The link to Baryta = barium hydroxide is incorrect.  Baryta, as used in photographic paper, is barium sulphate - a VERY different compound...77.101.234.177 (talk) 14:51, 24 March 2008 (UTC)
thread_title:  Baryta Link 

message: IMo, there's so much wrong with this article. Although the info is correct, it's badly organised and catergorised. I'm beginning a clean-up, starting with the sections and sub-sections. I'll try and find some decent refs too. Comments? Baffle gab1978 (talk) 02:20, 28 September 2008 (UTC)
replies: text: Go for it.  I might try to help a bit when I can see how to. Dicklyon (talk) 03:20, 28 September 2008 (UTC)
replies: text:  That would be most appreciated, thanks. I think the first thing is to tease out the good content and throw out the rubbish or repeated info and section it properly. Then, some further information and refs to support it. Sadly, most of the photography pages are in a similar unreferenced mess. It seems folk have dropped in and thoughtlessly added text. Just proof-reading the page (or others) would be helpful. Baffle gab1978 (talk) 21:45, 28 September 2008 (UTC)
replies: text: Actually, I think the photography pages have made a lot of progress in the last couple of years, and are not as bad as the average wikipedia page.  But still there's a long way to go to make them up to standards like WP:good article. Dicklyon (talk) 23:21, 28 September 2008 (UTC)
thread_title:  Clean-up 

message: It's not clear if any of the section on emulsion characteristics apply to colour printing.
Maybe it would be easier to have a separate article on colour photographic paper ? Rod57 (talk) 13:05, 4 October 2008 (UTC)
replies: text: I can't see how a separate article could be helpful. Dicklyon (talk) 23:57, 4 October 2008 (UTC)
thread_title:  Emulsion characteristics and colour 

message: The section on chlorobromide paper indicates that it "Containing a blend of silver chloride and silver bromide salts".  Depending on the definition of "blend", I don't believe that is right. It is, instead, silver (chloride bromide), that is, a latice containing either a chlorine atom or bromine atom in the place where bromine atoms go in silver bromide. The result has properties somewhere between those of silver chloride and silver bromide. This is distinct from an emulsion made from grains of silver chloride and grains of silver bromide. Gah4 (talk) 21:07, 16 April 2015 (UTC)
thread_title:  Chlorobromide