Quote Originally Posted by FotoRR View Post
Wish to use Ilford Perceptol developer for ORWO UN54 exposed at 100. Need Time, Dilution and Temp.

fotorr
I have never used this film, but I have used Perceptol, which is a developer that is speed decreasing.

May I recommend a film speed test? Expose one roll in what is normal lighting for you. Bracket your exposures, say EI 25, 50, and 100 - three shots per 'scene'.
Now develop for a standard like time. I see Perceptol is used at around 10 minutes and mostly at half the emulsion speed, so try 10 minutes.

Now you need to use a second test roll where you shoot a roll based on an evaluation of the shadow detail and the shadow detail only. You need to expose the film in similar lighting conditions as your first roll. Highlights and midtones do not matter at this point.

Say that you like the results at EI 50. Cut your exposed roll into thirds. If your first test roll where you liked the shadow detail had highlights that were too dense, you cut developing time. Try 9 minutes, or 8 minutes. If the highlights were too weak, increase dev time. Try 11 or 12 minutes.
Repeat as many times as are necessary.

The benefit of doing this is that you will know exactly what to expect from the film when you underexpose, when you overexpose, when you underdevelop or overdevelop. That is very valuable knowledge to have.

Even if somebody here was able to give you a recommendation, it probably wouldn't work very well for you because the shutter of your lens is a little different, your metering technique is not exactly the same, your lens contrast varies, your lighting conditions are not the same, your water quality is different.... etc etc etc. If you print in the darkroom you likely have different paper developer and paper than somebody else, which require different negative contrast than other people's materials. Just do a little bit of work, and then reap the benefits.