Usenet Newsgroups Re: Pyro Developers Question. From: dickburk@ix.netcom.com (Richard Knoppow) "Lew" <lew1716@gmail.com> wrote in message news:db44e57c-6a79-42e1-9f85-f4f839786793@c10g2000yqi.googlegroups.com... Isn't there also the claim that, as development & tanning progress in highlight areas, the emulsion physically compresses (as a result of the tanning) thereby holding less developer? ie there is even more moderation of highlight densities than there is via the mechanism of developer exhaustion alone. I haven't tested this extensively, but my limited experience leads me to believe that, on a very sunny day, with the sun overhead, plus areas of deep shadow, using iso 200 - 400 films, I did obtain easy to print negatives with plenty of highlight detail.     I have never seen this suggested and doubt very much if it happens. Developer penetrates by diffusion from the surface. The "hardness" of the gelatin has little to do with it. AFAIK, there is no such action due to differential hardening.     There is a differential imagewise shrinkage of the emulsion but it probably happens as the emulsion dries. One result of this is an acutance effect due to a difference of index of refraction along the demarcation of high and low density areas. It also produces a distortion of the image on a very small scale but enough so that tanning developers are undesirable for photo metrology purposes. -- -- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com Subject  Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Jobo atl3  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Pyro Developers Question.  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Jobo atl3  Re: Pyro Developers Question.  Re: Pyro Developers Question.