Max said:
But since I'm here, does anyone use sodium metaborate with pyrocat? I'm used to working with rollo pyro, and I always did a presoak with sodium metaborate, and another post-fix, pre-wash sodium metaborate soak.
The rollo pyro instructions say this post-fix soak is when most of the stain forms (I know nothing of the chemistry involved here).
I didn't get much stain with pyrocat. Is it the lack of sodium metaborate, or just a symptom of the really thin negs?
A few comments, all relevant to the thread but not necessarily to this message.
First, don't use a sodium metaborate pre-soak with Pyrocat-HD. The pH of a metaborte solution is not compatible ( lower in this case) with the working Pyrocat-HD solution. If you want to use an alkaline pre-soak try instead a weak carbonate solution.
Second, although there may be some exceptions by batch, the true film speed of BPF 200 is about EI 100, the same as that of Ilford FP4+, or perhaps even slower, and this is with all developers. This fact has been amply documented in the literature and I have confirmed it in my own comparison testing. So rate BPF at an EI of 100 or even less if you want good shadow detail.
Third, thin negatives are almost always a result of under-exposure in the camera, either caused by rating the film at too high an EI or by improper metering techniques. Properly exposed negatives may look a bit flat if underdeveloped but they don't usually look thin.
BPF negatives that have received the same exposure look almost almost identical in density (but not in the color of the stain) when developed in Pyrocat-HD 2:2:100 as when developed in a standard 2:4:100 dilution of Rollo Pyro. .
As for developing times, here is what I recommend for BPF with the 1:1:100 dilution. This is based on rotary development in tubes at 72 degrees F with gentle but constant agitation. If you develop in tray or tank increase time by about 15-20%.
Graded silver papers -- About 6:30 for scenes of normal contrast.
Variable contrast papers -- About 9:30 for scenes of normal contrast.
AZO -- About 12-14 minutes for scenes of normal contrast, or about 7:30 with the 2:2:100 dilution. If you develop for AZO you should also be able to print on a VC papers of Grade #1 with the same negative.
Sandy