Here's a good one for all you students of sensitometry. I am trying to jury-rig a sensitometer, as I don't have access to a real one. In my last job, my employer had an EG&G flash sensitometer; alas, we have parted company.(posted 8299 days ago)As a light source I am planning to use my trusty Metz 45CT-1 flash in manual mode. This will give me an exposure time of about 1/300 sec, which is within the range where no reciprocity correction will be required for the two films I am planning to evaluate. Unfortunately, it will also provide way more illumination than I need to expose my film, through a Kodak 10-inch step tablet.
Okay, here is my dilemma: I require about 0.008 MCS of light in the toe region of the film to expose it properly. If I measure the light outpit of the flash with a Minolta flash meter, is there a formula by which I can express 0.008 MCS as an f-stop/shutter speed combination? If I can do the calculation, I can make the required neutral density filters so that the film won't be grossly overexposed.
I should add that I know full well that this will not give me anything in the way of true film speeds. However, I can compare two films, one of which I have exposure/development combinations which work for me.