There have been a few threads here in the past asking how to use a scanner as a densitometer. Someone suggested me a source of an inexpensive set of films of known densities. I have lost that information and can't resume the project.(posted 8068 days ago)My scanner can scan transparent material of fairly large sizes so I can use Kodak density tablet, but if I try to exchange data with those who use 35mm scanners I need to find a micro tablet that fits in their scanner... (Besides locking exposure and getting the raw data from the scanner saved in a TIFF file, which my system can easily do.)
The idea is to fit a smooth function (perhaps polynomials or continued fractions) into response pattern from scanner using step tablet to do interpolated modeling, and then invert that model to estimate density from other materials. I prefer to have multiple sets of tablets of known densities so that I can verify the model accuracy without reusing the data that created the model.
For those who use 35mm scanners might prefer to include many steps in one frame so that they don't have to feed many frames to get one curve. This is only an experimental thought. How do people here do densitometry? One graycard and modifying exposure in each frame using shutter/aperture/ND filter/etc? I think contact printing step tablet is a good way but again I don't know a step tablet in 35mm size... maybe photographing reflective density tablet?
I am looking for product information (including information for free samples for research purposes :-) that can potentially be useful for these purposes.