Questions concerning stoeckler divided developer

Hi all I plan to give the stoeckler divided developer a try. I'll be using it with fp4. Has anybody tried mixing a more concentrated stock solution and diluting it lat er? I'm also wondering what the shelf life is. It seems to me that one should be able to use a faster EI since showdow development is independant of highlight I currently use 80. Any thoughts? Also, any suggestions for a starting point for dev time testing would be appreciated.

I also wanted to say that the thoughtful comments regarding the recent disaster in New York and Washington show a high level of sensitivity amoungst the contrib utors of this forum. Good show.

Thanks Rob

Try looking at www.unblinkingeye.com, and the section on divided D-23 developer for more info on the subject. In my version of the divided developer, I keep a concentrated version of the second part of the developer, but mix the first part fresh every time. I have been using TMax 400, and rating it at 400. I have no experience with Ilford films and this developer.

The 100 grams of sulfite in solution A should give it very good keeping qualities. D-23 was designed to be reused and replenished. It is probably feasible to make a concentrated solution by dissolving in 250ml of water instead of a liter--then you could dilute 1+3 with water for use. In the article by Jim Veenstra on Divided D-23 (published in View Camera), the author gives developing times for T- Max 100 and 400 at the manufacturer's rated speed, but he rates Tri-X at 200.

Rob. You seem to have slightly the wrong idea of how divided development works. The shadow develoment isn't independent of the highlights at all.What actually happens is that shadow development proceeds normally, but areas of heavier density, the highlights, are starved of developer. This tends to give an early shoulder to the density curve of the film, and prevents highlights reaching an unprintable density, even with heavy exposure. Shadow and low-midtones are hardly affected at all.In short, no, a two bath developer won't give an increase in film speed.