development testing times : LUSENET : Black_and_White_Photography : One Thread

I was hoping for some help in establishing N- and N+ times. I'm using the paper density range - ZI = ZVIII as my basic equation. I was about to expose for ZIX and develop for ZVIII for N-1 etc. Is this a good method? My concern is that the definition for N-1 development is ZVI moving to ZV. Will the ZIX to ZVIII be too much?

Thanks for your help. This is a great forum by the way.

-- Anonymous, February 22, 1997


It has been a few years since I did my test exposure and development to establish my film speed. But I believe if you expose for zone 9 and develop to bring it to zone 8 then zone 6 will not move to zone 5. It will not move a full zone infact I think it will only move about one fourth of a zone. The movement becomes progresively less the further down the scale you go. To be completely accurate all exposure and development tests must be read with a transmission densitometer. Also all exposures must be made on a gray card on consistent light. Development of each sheet of film must be kept as consistent as absolutely possible. Once this is established for that particular film and developer you are home free. I hope I have remembered correctly. Dell

-- Anonymous, February 22, 1997

Dell, thanks for your response. I just realized I typed in the wrong calculation for ZVIII. It should be Paper Density Range + ZI = ZVIII. I apologize for the error. - Doug

-- Anonymous, February 22, 1997

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