I created this card to help with film processing. I practice Steve Sherman’s minimal agitation technique with diluted Pyrocat HD and usually Ilford FP4+ film. The times and periods reflected on the card are designed to help me create negatives that print well on Ilfords MGFB Warmtone papers with a #2 filter. The chart is not meant for scientific accuracy but rather a guide for development adjustments based on SBR and my personal desires for the film/developer/papers I use.
The colored time periods are agitation points and the underlined bold values are normal removal/dump times. Since most scenes do not have a perfect 5 stop SBR, I can adjust one way or the other in total time processed. My initial agitation is always 2 minutes, then I divide the total remaining time by 3 to get my inversion points (20 seconds each). So if my actual SBR is 5.2 stops (high EV – low EV) I would use 8 minute agitation intervals after my initial 2 minutes for a total time of 26 minutes. If the scene had a couple of outlier bright areas I might pull back to 7:30 minute intervals or take a minute off the end. Field notes will help with that determination. Beyond 6.5 stops or less than 4 stops I need to adjust dilution and agitation. For Delta 100 I reduce time by 1:00 to 1:30.
If I shoot two shots of the same scene I may pick a development point and then make adjustments on the second sheet. The guide shows me that I need more time for expansion than I do for contraction. If I processed a 4 stop SBR scene at 32 minutes, I may need to go as long as 3 minutes longer to further expand contrast. Similarly a 6 stop scene will contract in less than 2 minutes adjusted.
Your feedback and questions are welcome.