I just purchased a near new CPA-2 processor and have a few questions regarding drum speed for film processing. I mainly will be using it with the expert 4x5/5x7 and 5x7/8x10 drums. I previously have used them on a uniroller and had very good results but have cut my processing time dramatically to keep contrast down. I didn't receive any information with the Jobo but understand the F setting is for film. Last evening I did a run of 4x5 as a test and found contrast to be quite high using the times from the uniroller days. Now I need to reduce time from the 6 minutes I generally find good for normal processing and am concerned it will run less than 5 minutes. For consistency I do not want to get below 5 minutes. Now the question, I can adjust the speed of the rotation to a slower speed than the F setting but want to know if this will put an excessive load on the motor. I believe that going to the lowest speed will reduce the need to cut process times below 5 minutes. I will also say that I'm running most of my film with 1:47 Ilford HC and don't think I should dilute any more due to sq in area vs chemical volume vs oxidation of the developer. Any experience with this?