I have just done a quick sheet of film Arista/Foma 100 in the Foma's Excel developer. I got the very useful 1 litre pack.
I had a previous BTZS file for the Arista 200 iso film in Xtol so I made some educated guesses based on past experience using Pyro with both films. From my own tests with Pyro the actual film curves [100/200] are characteristically identical with the 200 exactly double the speed.
I created an ExpoDev palm pilot file based on the Foma 200/Xtol curves, adjusted the iso for each curve and took a very demanding shot in full sun with mid depth shadows. EV 14.2 [Highlight] EV 10.6 [Shadow] -- with an incident meter. This represents about 8 stops. BTZS on the palm calculates both the exposure for that sheet and an individual development time for the sheet relative to the tested curves.
Remembering that this is not a correct set of test sheets purpose produced for the developer. My observations are as follows.
The Excel developer is giving excellent shadow detail and contrast. The grain is tight and sharp with very good highlight control.
If the Arista sheet film is Foma, which I'm lead to believe it is then this is a very nice combination.
Based on what I have printed today from a single negative I'm prepared to do a full set of tests [about 6 sheets] to really assess the potential of the developer.
Actual tonality was very pleasing.
If you wish to try a shot yourself these are the initial times etc. I presume the following information could be used also for the 120 roll film if it is the same emulsion. The developer times provided suggest it may well be.
Developer mixed in RO water.
Developer diluted with RO water 1:3 [ 1 part Excel + 3 parts water]
Constant agitation -- BTZS tubes or Jobo [Shake vigorously initially 10 seconds to thoroughly wet the film and NO water pre-wash ]
Estimate --- add 15% - 20% for intermittent agitation [First 30 seconds constant then 4 inversions on each minute.]
These times are based on a diffusion enlarger, mine is a DeVere 504.
My test neg was definitely not thin but printed very easily.
Approximately a grade 1 - 2 filter on a multigrade paper.
ISO -- 50 -- This would equate to a zone system shooters N or normal value Try 80 ISO if the negs are too Bullet Proof for you.
Approximate development time -- 6:00 minutes [constant agitation.]
I really like the results so I intend to do a full set of BTZS files for the Foma 100 with the Excel developer which I'm happy to pass on to any other BTZS users.
Thanks to Chris in Sydney at Blanco Negro for stocking the developer.
02 - 96984552
I also have some dev to try. I have a couple of 120 rolls to dev. I also have some 4 x 5. I will also stick to stouffer shots through as well. I will have a look on the densitometer and see how they come up. FP4 and Acros. Thanks for the info. And thanks to Chris.
I checked the denso readings on the highlights and they are thick but I had absolutely no problem printing them. As a rough guess on my figures probably about half a stop over. I am very impressed with the smooth creamy tonality the Excel/Foma 100 has given. Rather rich.
It is very different to my normal PMK so I see it having a very real subject specific role. Mind you it appears to offer wonderful control for any subject.