Pyrocat/APX 100 dev times needed....
I have spent an hour trying to find times for the above combo and very little has come up. The Massive Dev Chart has nothing. I love the stuff in 120, so bought my first box in 5x4 ages ago, which turned out to be my last as it was discontinued. It sat there for a year as I could see no point in using it as it is no more.
However, I have now used some and just cannot find times for enlargement. The best I could find was 13 mins at 21 degrees C for a condensder or 9 minutes at 27 degree (no further detail).
I intend to diffusion (very soft colour head) enlarge. and dev in a combitank.
I only have 4 frames, 3 having very brutal highlights (sun on water), one being Normal. I plan to do them all together based on the bright scenes, print those on VC and the (presumably flat N neg if deve'd for the bright scenes) on graded for more oomph.
Any starting points....I only went to play and possibly got some nice frames....hows about 11 mins 20 degs C? I played safe and metered at ISO 64.
I've posted before on APUG about this combination, and I just wanted to add that 120 format APX100 at ISO 64, with Pyrocat-HD at 1:1:100 with minimal agitation (1min initial and 5 gentle inversions every 2min) at 68deg F for 11 minutes gives good results for a condensor enlarger. So I think your 11m at 20C is a good starting point for your subject matter and enlarger setup.
First I tried 120 rollfilm, exposed at IS0 50 in strong direct sun (spain). I used Low ISO as I was to reduce development with a std dev. I then decided to develop in pyrocat.
I gave 2 min presoak, 13 mins in 1:1:100 @20 degs C, constant agitation for 1st minute, then 10s every 2 mins.
Results: Printed nicely on VC paper at G3 1/2. In retrospect I would rate at slightly faster and develop for about 15 mins to print better at about G3 I would hope.
Second I tried 4 sheets of 5x4 in combitak for same time at same temp, same agitation. 3 frames had been exposed to scene with over 10 stops and another to normal scene. I was amazed to find that the contrasty scenes printed nicely on G2 1/2 VC and the normal scene was struggling at G4. This just show how incredibly good the dev is at holding exceptionally bright highlights (in this case, sun on water and blasting thru cloud.
I think for next time, rating at close to box speed will be fine along with another 25% dev time or so.
I then ried tha flat neg on graded paper, finding that it printed nicely on Grade 4 Zone VI FB. Still had all the halmarks of an underdeveloped (I had evidently also have been mean on exposure) neg. This is roughly in line with Barry Thornton finding about 1 grade difference (as I did) betywen VC and graded with these devs (Exactol/Dixactol from him). I have certainly not come close to the two or more grade difference that others have reported. However, this could be that I am not trying to maximise stain. I get a good rich brown image, but use acid stop and fix, with no afterbath. I am assuming that those who use alkali stop/fix may get a little extra stain, not that visible to the eye, but very dense to graded paper.
Overall grain is fine, far, far finer than Dixactol, but not quite as fine as Exactol Lux, but not far off at all. Acutance is great. Just dev'd a 10x8 section of a 24" to see how the edges looked and it was very good indeed.
At this early stage, I can say again that even if Dixactol and Exactol Lux were available again (as presyscol is), I could see no point in me using them again - pyrocat seems the ideal compromise of grain and sharpness for LF. Cannot wait to try on 10x8.