Help with expansion and contraction

jstraw · Dec 1, 2006

I'm a bit unclear on how best to go about determining N+1 and N-1 development times.

I could meter for Zone VII, increase my development time incrementally till I achieve the same density as a normally developed, Zone VIII exposure for N+1...and do likewise with a Zone IX reading, reducing development time to determine N-1.

Is there a less time-consuming way to do this?

BBarlow690 · Dec 3, 2006

Not really.

If you try increasing/decreasing development time by 15 or 20 percent you'll likely be very close, cutting down the iterations you need to do. The test takes less than an hour total, not including negative drying time. Then, you have the information you need forever!

Maybe this will help a little: I do test negs at the end of a day or session of photographing, just as I do proofing at the end of a printing session. All the necessary stuff is out, set up, and available. It requires a little, but not much brain, which is about all I have by then. The negs get developed during any subsequent developing session, and proofed to read when I next do proofing. In other words, I fit testing into life, rather than rearrange life to test. Seems less odious that way.

Why am I retesting? When anything changes - trying a new film, obviously. recently, in a foray into previously-unexplored medium format. I retest if proofs show something goofy that I can't explain any other way. A couple years ago I redid it all when the new Tri-X started coming off the lines. But I try to minimize testing's depressing effect on my gumption.

Good luck! Charge the Ambush! It really ain't that bad.

jstraw · Dec 3, 2006

Thanks Bruce...I'll bite the bullet and test.

Is the alternative to eyeballing Zone System testing to use actual sensitometry, such as 1.20 over B+F for ZVIII (and for N+1 for ZVII and N-1 for ZIX) for a diffusion source?

Or do you recommend proofing and subjective testing?

noseoil · Dec 3, 2006

The easiest way is to use a densitometer and BTZS techniques. That having been said, the easiest way (without the equipment and training) is to just take two shots of a scene, if you aren't sure about development time. The hard part is relating this development time in terms you can actually use. Here is one way to do it. I just use a Stouffer printed paper zone scale for this method, to have a constant print scale to work with. It is based on your paper of choice.

The BTZS way of dealing with contrast is the best I have found (high value ev minus low value ev plus 5 is your "sbr" or scene brightness range for any shot or 14 - 11 = 3 + 5 = 8). Develop the shot and see where your printed values fall. is zone 3 really zone 3 and zone 7 really zone 7? If so, use a sheet of graph paper. Along the left column every 1/2", sbr numbers from five up to 10 or 15 (y axis, whatever, but 5 is at the bottom and 10 at the top). Along the bottom line (x axis) is the time line in similar increments of 1/2" with low number at the left and longer times at the right.

Let's say the time was 12 minutes and zone 3 & 7 were correct (full texture at top and bottom). Plot a point across from sbr 8 and up from 12 minutes. If the print shows an under-development, then you have less contrast and your sbr wasn't 8 in the print, but perhaps 9 (1 zone short of your target). Plot a point at sbr 9 for 12 minutes. This is just guess work with a zone scale, but once you have a few scenes mapped out and the points are plotted, you can use a french curve to draw a line which is the average of these points. You will have plenty of information at your disposal for plus and minus development once this is done.

Draw this on a sheet of paper to see what it looks like and it will be easy to understand, after a while. Best, tim

jstraw · Dec 3, 2006

noseoil said:
The easiest way is to use a densitometer and BTZS techniques. That having been said, the easiest way (without the equipment and training) is to just take two shots of a scene, if you aren't sure about development time. The hard part is relating this development time in terms you can actually use. Here is one way to do it. I just use a Stouffer printed paper zone scale for this method, to have a constant print scale to work with. It is based on your paper of choice.

The BTZS way of dealing with contrast is the best I have found (high value ev minus low value ev plus 5 is your "sbr" or scene brightness range for any shot or 14 - 11 = 3 + 5 = 8). Develop the shot and see where your printed values fall. is zone 3 really zone 3 and zone 7 really zone 7? If so, use a sheet of graph paper. Along the left column every 1/2", sbr numbers from five up to 10 or 15 (y axis, whatever, but 5 is at the bottom and 10 at the top). Along the bottom line (x axis) is the time line in similar increments of 1/2" with low number at the left and longer times at the right.

Let's say the time was 12 minutes and zone 3 & 7 were correct (full texture at top and bottom). Plot a point across from sbr 8 and up from 12 minutes. If the print shows an under-development, then you have less contrast and your sbr wasn't 8 in the print, but perhaps 9 (1 zone short of your target). Plot a point at sbr 9 for 12 minutes. This is just guess work with a zone scale, but once you have a few scenes mapped out and the points are plotted, you can use a french curve to draw a line which is the average of these points. You will have plenty of information at your disposal for plus and minus development once this is done.

Draw this on a sheet of paper to see what it looks like and it will be easy to understand, after a while. Best, tim

Thanks Tim. It's all perfectly comprehensible and I really appreciate the advice.

One question, is a Stouffer printed paper zone scale just a properly proofed step wedge? Enlarged or contact printed?

mikebarger · Dec 3, 2006

You might look at Fred Pickers Zone VI workshop book on ebay, generally less than $7.00.

This is a excellent zone system primer.

Mike

jstraw · Dec 3, 2006

mikebarger said:
You might look at Fred Pickers Zone VI workshop book on ebay, generally less than $7.00.

This is a excellent zone system primer.

Mike

Thanks, Mike. I have a copy right here...bought it from Fred, back in the day. The Zone System is not an area of mystery to me but it seems that expansion and contraction testing seems to be routinely, poorly documented. The coverage of this subject in Picker's book is actually non-existant. He cover's normal development only. At least there's a lousy overview in St. Ansel's "The Negative."

Tim's advice is comprehensible, as is narrowing down guesses till I can place either a highlight readings that fall on ZVII and IX at 1.20 over B+F (if that's sound reaasoning).

noseoil · Dec 4, 2006

My "printed zone gauge" is just a paper strip which, I'm sure, doesn't relate to a proper scale like a step wedge, which is claibrated (printed zones, not "real" values). My method is crude, but the results give answers which can be related to a system which gives decent results. Strictly a trial and error approach, but it allows you to use "bad" guesses as part of the process for plotting the information to get good development. tim

jstraw · Dec 4, 2006

Thanks Tim.

Help with expansion and contraction

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