I must ask for help. I am drawing a complete blank on a famous book on photography that talks about just such things. I can't remember either title or author although the partial name is Henry but I think that's a first name. In any case the author researched the idea that silver halide content of the emulsion had any effect on tone rendition. He did a formal analysis of the emulsions and determined the maximum density possible from the emulsion. He found that there was NO relation between the two. The paper with the deepest blacks had a medium amount of silver, the paper with the least silver had a medium Dmax and the paper with the maximum amount of silver halide also had a medium Dmax. The tone rendition of the paper has more to do with the covering power of the metallic silver grains developed from the emulsion and can also be strongly affected by the surface of the paper. This is a case where only glossy papers are of interest because any texture will diffuse some of the light and reduce the contrast range. In fact, Kodak used to make a note of this for some papers which were available in several surfaces and texturs and several contrast ranges. The author also experimented with different developers and found that they had very little effect on Dmax as long as the developer was not diluted too much. In fact, he found that by accident he had standardized on using Dektol at 1:1 rather than the 1:2 Kodak recommends for most paper. This actually had little effect on the reflection density but extended the capacity somewhat. I never actually forget anything but it may take a while for this to pop back in. I am sure someone else can supply details in the meantime. I hate this; I expect all information that has entered my brain to be avaiable on demand instantly! Here, you, front and center NOW! Doesn't work. In any case, the tonal range of paper is not too difficult to measure. Its helpful to have a reflection densitometer but the densities can be approximately measured visually (even a Kodak Precision Print Scale will give you some hint). The _shape_ of the curve is important because it affects the visual impression even though a particular shadow and highlight density is the same. Developers for paper have some effect on curve shape just as they do for film, but the overall shape is more due to the distribution of halide crystals than on the developer, for either negative or print emulsions.
-- Richard Knoppow Los Angeles WB6KBL dickburk@xxxxxxxxxxxxx----- Original Message ----- From: "Janet Gable Cull" <janetgcull@xxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx> Sent: Saturday, November 29, 2014 3:19 PM Subject: [pure-silver] old papers and new papersI'm reading an article Les Myers sent me (from Online Photographer) about Voja Mitrovic. Here is an interesting statement by Peter Turnley: " It was also a time when the highest quantity of silver was in printing papers. Voja has indicated that there are certain qualities of richness in gray tonal values that he could never achieve with today’s papers, that he was
able to obtain in the late 'seventies and early 'eighties.Do any of you know which of today's papers are higher in silver content? or most like the older papers he may have been referring to? He didn't say specifically which papers he liked using, but did refer to the change
(down) at the introduction of multi-grade papers.Here is a link to the article, if you're interested. I found it most interesting to find that many of the "greats" didn't do their own printing. That's not what I'd have imagined. Anyway, I have enjoyed it,
and hope you do, too. http://theonlinephotographer.typepad.com/the_online_photographer/2014/11/top-classic-yoja-mitrovic-printer-to-the-greats.html Janet ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.
