Efke PL100 - high fb+f?

[Claude Sapp]

Thought I would try some PL100 instead of the FP4+ I have been using. I developed 4 sheets to test film speed in WD2D+ using BTZS tubes. Went for 10 mins @ 20C, seemed a good base development time until I could really test for development time.

The development looked fine, smooth stain and uniform on all four sheets, and the film speed test was successful. But, the fb+f looks really high. I mean, I can barely see through the fb+f half of the negative. My FP4+ in WD2D+ fb+f is almost clear, much clearer than the PL100.

I am going to try some different developer this weekend, probably D76, but has anyone else used the PL100/pyro combination and experienced high fog? FP4+/ pyro has never been an issue for me.

[Allen Rumme]

A couple of years ago I tested PL100 in both Pyrocat HD and D-76. In both developers, it had a fb+f that is 2-3 times what I routinely see with TM100 & TM400. In D-76 PL100 had a fb+f of 0.18 -0.20 while TM100/TM400 has a fb+f of 0.06 - 0.08. I don't have the Pyrocat numbers handy, but as I recall they were equally elevated. I don't use FP4, so I don't know what its fb+f numbers look like.

Anyway, that is my experience with PL100.

[Eric Rose]

Yes I think .18 was what I got using PL100 and PyroCat-HD. Still my main combo. Prints wonderfully.

[sanking]

With any specific film the b+f value should be close whether developed in a traditional developer like D76 or in a staining developer like PMK or Pyrocat-HD/MC. Stain is proportional to silver density, hence greatest in the highlights, least in the shadows.

If a film has developed fog, either from age or heat, the b+f values after development will be greater with a pyro staining developer than with a traditional developer. For this reason I do not recommend the use of pyro staining developers with very outdated film as the b+f values may be very high. This may not be of any consequence in silver printing, where exposure times are very fast, but for alternative processes any increase in exposure time is like the plague.

EFKE PL100, when fresh, has a very low b+f value. However, the b+f increases rapidly with age, much more so than with Kodak and Ilford films of equivalent speed. Ilford Delta and FP4+, and Kodak Tmax-100, with normal storage, will have a very low b+f after 3-5 years from date of manufacture. EKFE PL100 b+f levels will be very high after two years from date of manufacture.

Sandy King

[Claude Sapp]

I will have to check the date on the box of film, but I bought it late last year from Freestyle, and just recently am I running low on FP4+ so I opened the box of PL100 to test and use.

So, question, I usually test film with the BTZS method, but my densitometer is acting up so with this PL100 I was just doing the tests for film speed and then another round of tests for std dev time, similar to the Barlow/ Picker methods. My question is, if this fog I am seeing comes with age, and the fog is uniform, my film tests will still be meaningful whether I use fresh or dated film, right? I would think so, I would think the film speed test and standard dev time tests would be the same for fresh and dated film, but since the film becomes a bit fogged with age, printing times would just become longer with the dated and therefor a bit more fogged film, right? Or has anyone experienced or would one expect a change in film speed with age as well?

[sanking]

My question is, if this fog I am seeing comes with age, and the fog is uniform, my film tests will still be meaningful whether I use fresh or dated film, right? I would think so, I would think the film speed test and standard dev time tests would be the same for fresh and dated film, but since the film becomes a bit fogged with age, printing times would just become longer with the dated and therefor a bit more fogged film, right? Or has anyone experienced or would one expect a change in film speed with age as well?

It is hard to say what goes on with aged film. There may be some loss of film speed, but then again maybe not. If the b+f is not too high, say over about log .30, I would think it safe to expose based on your existing tests. If over log .45 I would test the film again.

I have a few boxes of Efke PL100 in 7X17 size and the b+f is about log .35. I am using it based on tests of fresh film with low b+f and results are fine.

Sandy King