Development times with Expert Drum?

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I have always developed my 4X5 in trays with +/- results depending on the number of sheets I was processing.

I want to buy an expert drum from Jobo and an inexpensive base to turn it. With the drum turning with constant agitation won't I have to change my dilution due to increases in contrast? What kind of changes will I have to make when processing with a drum?

Thanks

-- David X. Tejada (david@tejadaphoto.com), March 11, 2001

Answers

I take off about 15% of my time for the constant agitation. Some companies will give you adjusted times for their developers. I would to test anyway. It is a pain, but well worth it. I also think you will like drum processing your 4x5 negatives.Good luck!

-- Rick Lang (rickpho@aol.com), March 25, 2001.

I recently bought a Jobo processor. A friend who has one advised me that most film developer makers give times based on a condenser (rather than diffusion) enlarger, so you need to add time to compensate for use of a diffusion enlarger and subtract roughly the same amount of time to adjust for the use of a rotary processor with constant agitation. So I started with the film developer's recommended time and it seems to work fine.

-- philip tilton (pjtilton@concentric.net), October 04, 2002.

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