Archived posting to the Leica Users Group, 2005/11/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On 11/29/05 6:28 AM, "Martin Jangowski" <martin@jangowski.de> typed: > On Tue, 29 Nov 2005, Mark Rabiner wrote: > >> NO PHENIDONE either. >> It's DIMEZONE instead. >> Dimezone is a Kodak trade mark version for a Phenidone derivative which is >> more stable they say than Phenidone. I think it may be as different from >> Phenidone as sugar is to NutraSweet. > > > Phenidone, Dimezone and Dimezone-S are chemically close related. The main > difference for the user is that Phenidone is less stable and not as easily > going into solution in water. OTOH, it is a little more active, as a rule > of thumb you can replace Phenidone with about 20% more Dimezone-S. > > Xtol contains Dimezone-S, the typical copper colored solution after giving > Part I to the water comes from Dimezone-S. It will get colorless after > adding ascorbic acid and sodium sulfite. I routinely use DS-10 from > R.Suzuki (http://silvergrain.org/Photo-Tech/film-dev-recommend.html) as my > main developer for films like the Deltas, Acros and 400TX. Extremely fine > grain and good sharpness. > > Gr??e aus Hohenlohe, > > Martin Jangowski > >From his remarkable site of Suzuki's I found this truth to be more on the self evident side: "2. Image qualities of Ascorbate developers Does ascorbic acid developer have anything to improve the image quality? This is partly answered in US Patent 5756271, and in an Eastman Kodak product called XTOL. 2 Ascorbic acid, its isomers, derivatives and salts are in some aspects similar to hydroquinone in developing power and pH region where reaction is activated, among others. However, this similarity is very superficial. The oxidation products of hydroquinone (ones that are exhausted after developing reaction) is alkaline. This may accelerate development in the area surrounding areas of intense development reaction. On the other hand, the oxidation products of ascorbates are acids, potentially inhibiting development in areas nearby the site of intense reaction. This means that ascorbates are more desirable when adjacency effect and compensation effect are sought.3 " http://silvergrain.org/Photo-Tech/ascorbate-dev.html And a great new reference source for such stuff for me although I'm seeing sometimes stuff I don't go along with neck in neck with with the stuff which I'm all excited about. But it's good one don't believe everything one reads. Means one is not necessarily a Lemming. Mark Rabiner Photography Portland Oregon http://rabinergroup.com/