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Nick Stanislo
17-Aug-2004, 12:34
Can anyone recommend the proper compensation in times for 100 Tmax 4x5 developed in Tmax RS 1:9? Thanks in advance.

Michael Jones
17-Aug-2004, 12:59
Nick:

Try Great Yellow Father:

http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.jhtml?id=0.1.18.14.21.18.16&lc=en#adjustments%20for%20long%20and%20short%20exposures

Good luck.

Mike

Brian Ellis
17-Aug-2004, 16:00
The kind of developer you use doesn't matter since reciprocity is just an exposure adjustment to the metered time. T Max films, especially T Max 100, are better from a reciprocity standpoint than other films. The adjustments I use for T Max 100 are as follows: 4 secs metered = 5 secs actual; 8 secs = 14 secs; 15 secs = 27 secs; 30 secs = 1 min.; 60 secs = 2 1/2 min.; 2 min. = 6 min.; 4 min. = 15 min.; 8 min. = 35 min.; 15 min. = 1 1/4 hours.

The longer reciprocity adjustments increase contrast so when you get to the 15 sec. metered = 27 sec. actual adjustment you should reduce development times accordingly (unless of course you want the increased contrast). I use the following for contrast adjustment: 15/27 = N+1/2 (i.e. the increase from a metered time of 15 seconds to an actual time of 27 seconds will give the equivalent of N + 1/2 development if you develop normally so you have to reduce your development time to whatever your N minus 1/2 time is (unless you don't mind the increased contrast); 30/1 min. and 60/2 1/2 min = N +1; 2 min./6 min. = N+1.5; 4 min/15 min. = N+2; 8 min./35 min. = N+3. 15 min./1 1/4 hours = N+3.

I've seen other reciprocity and contrast increase numbers from other people. I use these because the workshop instructor did the testing himself and I have a lot of respect for him but if these don't work for you try someone else's.

Randy Bracey
21-Aug-2004, 19:13
Try these:

Metered/Adjusted (seconds)

1/1 (Kodak +1/3 stop), 2/2 (Kodak +1/3 stop), 4/5, 5/7, 6/8, 8/11, 10/15 (Kodak), 12/18, 15/23, 20/33, 25/42, 30/52, 40/73, 50/95, 60/117, 80/163 100/212 (Kodak 200), 120/262, 160/365, 180/419 (Sexton 420), 200/473, 240/585, 300/757 (Sexton 840), 320/816, 400/1057, 420/1119 (Sexton 1260), 480/1307, 640/1824, 800/2363, 960/2919

Some of these values are from Kodak and John Sexton. Others result from my own testing, regression analyses, and wild a** guesses.

Other published sources exist. Howard Bond in Photo Techniques?

Use them as starting points.

Naturally, they can be rounded to suit your own needs.