Not until I just spent the last 30 minutes digesting it ! You are more geeky than me Bill , and I have 2 t-shirts and a cap with the word GΣΣK written on them (given to me by my lovely wife).
Originally Posted by Bill Burk
The only eBay search I've had running for about the last year is one for a sensitometer, and after reading that thread I have even less of an idea which brand/model to look out for. I hope your EG&G sensitometer is proving useful, you certainly spent some time getting to work it out. Surely there have been ones made since, that are at least as accurate (and feature-full) but not so old fashioned.
I'd prefer not to use my enlarger to expose a step tablet into my film because I'd then want to test my enlarger lamp response/warm up time at different filament temperatures and then try to control for that which doesn't sound too appealing. I have already tested my camera's shutter speeds (and had the CLA guy do it too) so I'm more comfortable with those being repeatable and accurate to within 5-10% (my intended accuracy of this Process test).
Perhaps if I get a sensitometer my quick Process Test will change to using that, but for now I will use my camera, and either a Tx step tablet in the manner I describe above or a reflection test target illuminated with either the sun at a similar time of the day (or an artificial light source) and vary the amount of light by adjusting the aperture over its entire range (the original idea I posed with this thread and the 'easiest' to do if one doesn't have access to a step tablet or sensitometer.)