How To Use Stouffer Step Tablet?

[tomwilliams]

My mistake on that Photographer's Formulary price - the $20 was for a 35mm sized tablet.

[Kiwi7475]

If you can, get the 31-step which gives you 1/3 stops. May be overkill now but you may find it useful.
In fact if you overexpose it (so that there’s more than one max black step on your print), you can get the precise time just by counting how many are indistinguishable, so in one step you can get both max black and the min exposure time for it (the 1/3 step helps nailing it with more precision). Basically decrease the time that you used to expose it by the number of stops before the last max black (e.g. if there’s 4 indistinguishable blacks and the strip is in steps of 1/3 of stop, then basically reducing it by 3 x 1/3 = 1 stop or half the time will move the max black to the top and it would be the only max black in the next test with a strip). That’s accurate to +/-1/2 the step size in the strip. Obviously you need to get at least 2 max blacks for it to work. But you can start really long in time since you have 10 stops to play with in the strip.

[tomwilliams]

Thanks Kiwi. I popped for the 21-step tablet a bit before reading your post.

[brittonie]

Brings back a memory when I was a student at RIT in the mid 1970s. Went something like this: I was taking a Materials and Process course under Hollis Todd. About midway through the semester, Hollis Todd said in class that the contrast of a paper did not change with the developing times, only the reflection densities got higher. I stopped by his office and told him that I begged to differ with this teaching (published in his book Photographic Sensitometry). He looked at me and told me to prove it. Spent the next week or two conducting test. Using one enlarging paper (most probably Varigam or Varilour), with a step wedge to calculate the paper's contrasts for different developing times. My readings indicated that the contrast did change with increased development times. Wrote it all up and quite nervously presented my findings to him. He sat back in his office chair and read my findings. Then said something like "you know what this means.... you just earned an A for the course." He told me that when he and written his book (probably 6+ years earlier) his teaching was correct for graded papers, but it was not correct for the VC paper that I was using. From then on I would stop by his office every week to engage in a great academic discussion. Still have one of the test strips that I made back then (attached).

Reading this story just made me so warm and fuzzy 💜

[Serge S]

Great story, goes to prove, it's good to check for yourself

Brings back a memory when I was a student at RIT in the mid 1970s. Went something like this: I was taking a Materials and Process course under Hollis Todd. About midway through the semester, Hollis Todd said in class that the contrast of a paper did not change with the developing times, only the reflection densities got higher. I stopped by his office and told him that I begged to differ with this teaching (published in his book Photographic Sensitometry). He looked at me and told me to prove it. Spent the next week or two conducting test. Using one enlarging paper (most probably Varigam or Varilour), with a step wedge to calculate the paper's contrasts for different developing times. My readings indicated that the contrast did change with increased development times. Wrote it all up and quite nervously presented my findings to him. He sat back in his office chair and read my findings. Then said something like "you know what this means.... you just earned an A for the course." He told me that when he and written his book (probably 6+ years earlier) his teaching was correct for graded papers, but it was not correct for the VC paper that I was using. From then on I would stop by his office every week to engage in a great academic discussion. Still have one of the test strips that I made back then (attached).

[Drew Wiley]

First of all, are you using the step wedge via contact or via projection in an enlarger carrier. You need to match it to your technique, whether contact printing or enlarging. If the latter, your results will be erroneous unless your light is totally even when it reaches the step tablet. I prefer the kind of Stouffer tablet on a piece of 4X5 with the strip cut in half, side by side, rather than having all 21 steps in linear configuration. It's also important that the color of the fbf on the step tablet approximate that or your own negatives. Some of the old used tablets are terribly yellowed. The new ones are quite neutral, but that might work against you if you are trying to calibrate pyro stained negatives.