Eddie, its 52 years since I held my first camera and in all that time I too have never heard of "SBR" or "EFS" so have to make a guess and hope I understand them.
But I reckon SBR is subject brightness range in f stops, and EFS is Effective Film Speed,
I recently tested the film in 4x5" size and found it defective. I reported it to the manufacturar. Wait for the response.
Originally Posted by SteveH
Originally Posted by eddie gunks
I have never tested the Foma film in Pyrocat-HD so can not offer much advice. However, unless it is very different from other ASA 100 films I would suggest a time of about 12 minutes at 70F using tank development and the 1:1:100 dilution of Pyrocat-HD. That should certainly get you in the ball park for silver printing, though you may have to make some adjustments with VC filters.
Subject Brightness Range is a BTZS (Beyond the Zone System) term that calculates the subject luminance range of the subject in stops when using Davis' incident metering system. SBR of 7 is considered normal. When you do BTZS testing the SBR of the subject determines how much develoment is needed.
EFS means effective film speed. Generally the speed of a film in a given developer is not constant, but increases with time of development.
Understanding and using a system of sensitometry may help one make better negatives, though some don't consider it necessary.
One major problem of the BTZS is you really need a densitometer, but in reality its only taking the Zone System and expanding on it, which seems to make a lot of sense if your producing prints by alternative processes.
Pyrocat-HD is a superb developer and once you've settled on your dev times and effective EI it's usually very easy to use a different film and as Sandy King says be in the ball park, then tweak it to suit yourself.
My own tests with Pyrocat-HD were made with Tmax100, but Tmax400, Fortepan 400 and EFKE PL25 are just as easy to use, however the Fomapan 100 & 200 films are quite different. They really do need testing afresh, the ball-park times etc don't quite seem to work, the results are extremely contrasty. I have 30+ rolls of 120 and a few boxes of 5x4 and 9x12 so I jhave to get it right. When I had to use FP4 & HP5 recently, two films I've not used for 20 years (the only 120 B&W films available in Chile), it was quite the opposite my ballpark dev time 15mins 1+1+100 @ 20°C worked perfectly.
I'm adding that numerous posters on APUG state that their EI's for Foma films are 2 stops below the box speed, my guess is my own test will indicate something similar.
My notes show that I got good results by rating 35mm Foma 100 at an effective film speed of 50 and semi-stand developing for 14 minutes with Pyrocat-HD 1+1+100 @ 20°C.
Originally Posted by Ian Grant
great! thanks all. i will try 12-14 min. tonight or tomorrow. i shot 2 negs for each subject today and i will try 13 min....what the heck ( i can adjust the 2nd neg accordingly). i also shot 2 sheets of the same scene at twice the exposure. what would you all suggest for a decrease in development % for a one stop increase of exposure? ball parks are fine. i play well in ballparks. :)
i have very good results with foma 100 in hc110 so i anticipate the same using pyrocat hd. i ma trying to set myself up for some van dyke and kallitype printing. thanks again. i will report back.
The blue base is not leftover anti-halation dye. This film, in medium format, has a blue tinted base. I've seen it myself and it is so described in the manufacturer's documentation.
Originally Posted by sanking
i developed 3 sheets tonight. i rated the foma 100 at 50. i souped em at 70 F for 12 minutes. they look great! i will try and print them in a few days. i will try them with regular B&W and with my "new to me" van dyke printing. stay tuned.
i shot 3 sets of negs. 2 metered "normal" and one with a bit extra. (the normal was 8 sec. the next one was 20 sec.) the 8 sec neg looks good. the 20 sec neg is much denser. i will try and print both using van dyke and regular B&W and see how i do. should i decrease development for the next over exposed negs? i have another neg for every exposure i made. if so, by how much?