----- Original Message ----- From: "DarkroomMagic" <info@xxxxxxxxxxxxxxxx> To: "PureSilverNew" <pure-silver@xxxxxxxxxxxxx> Sent: Monday, October 18, 2004 10:36 AM Subject: [pure-silver] Re: Polycontrast Paper Performance / Cold lite > My one-time experience with Selectol Soft brought paper > contrast down by > less than 1/2 grade. Since I get similar or better results > with changing the > factor of factorial development (FB papers only, of > course), I gave up on > soft developers and the increased darkroom complexity they > bring. > > > > > > Regards > > > > Ralph W. Lambrecht > > I am puzzled by how the developer can affect paper contrast at all. Prints are developed to "completion", that is to the highest contrast the material is capable of. Negative film is not developed to completion but rather to some desired contrast. Paper contrast would also vary somewhat if developed less but the main difference would be a loss of density in the shadows. What experimental data shows is that once exposure and development are sufficient to obtain full black from the paper that variation in development time simply moves the characteristic curve horizontally along the graph but does not change its slope significantly. Of course, this varies with the paper. A "low contrast" developer like Selectol-Soft or Agfa 120 develops more slowly than a more active developer like Dektol, but, unless there is some selection of grains by the developer, the contrast should be the same provided the same shadow density is reached. Perhaps there is something here I don't understand, if so I would certainly like to. My understanding is that the contrast of paper is determined mainly by the distribution of sensitivity of the silver halide particles in the emulsion. I will define contrast as I understand it as being the range of difference of exposure that results in a given range of density in the image. In a print that density range is from paper white to the maximum black the material is capable of. --- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx ============================================================================================================= 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.