Zone System & Reciprocity Failure

[james mickelson]

Andrew, remember that the better the neg the easier to print. Dom what ever is neccasary to get a good neg because it easier than trying to salvage a bad neg. You end up wasting paper and chemistry and you never are able to calibrate your entire system properly. So when you come across an great scene or come up with a great idea, you struggle to bring forth all that it could be. James

[John H. Henderson]

Get Phil Davis' Beyond the Zone System. There is a chapter near the end on miscellaneous topics such as reciprocity failure. If I recall correctly, he says that sometimes, with some film and developer combinations, contrast can actually reduce.

Like for your non-reciprocity-failure exposures, you ultimately want to characterize your exposure and developing process through testing.

Of course, if you don't mind resorting to using variable contrast printing, and a little lack of predictibility, you can use the guidelines for developing reduction for your film and developer combination and get into the ball park.

[Andrew Pell]

Thanks to everybody for the all the replies, suggetions, hints and tips. It looks like I've got a fair amount of reading and testing to do and hopefully I'll be able to sort out some of my "difficulties."

Andrew

[bob moulton]

The previous answers indicate the connection between reciprocity and development. What I use is the following: If the indicated meter reading is 1-4 s, and I then figure out the time I should use, I regard that as N-1/2 If the indicated meter reading is 8-60s, and tthen I figure out the time, the development is N-1; indicated meter reading=1-4 minutes, Dev. is n-1 1/2; Indicated meter reading is 8m-60m, development time is N-2. Neat thing is that if the dynamic range of the scene is low--ie you would need a + dev. time to start with, you can use the excessive contrast reciprocity causes to your favor and adjust the dev. times appropriatey. Hope this helps. Bob

[Brian Ellis]

Hi Andrew - In response to the question you asked me, yes, if the extended exposure necessary to take reciprocity failure into account will produce the equivalent of N + 1 contrast in the negative with normal development, you would develop for N - 1 to end up with a normal negative. I'm not sure of the answer to your question about variable contrast paper. Brian