Quote Originally Posted by noacronym View Post
Since none of us here knows one another, there is not much basis for definitive laboratory testing. Now if the original poster had also posted the technical receipt from the company where he sent his densitometer to be calibrated then I'd take notice. Calibration of instruments is a daily routine for companies that use these kinds of devices. If a record studio using tape recorders is in the business of quality records and tapes, it would be the engineers job to check tape head alignment, azimuth, and do tests on frequency response, probably before each studio session. A densitometer needs the same attention. When you send your oscilloscope off to Tektronics to be calibrated, you undoubtedly receive a printed report back with your scope. Densitometers can go out of calibration in one day, if you don't keep on top of them every minute. Anything less is just sloppy procedure, and the results are worse than worthless.
I wouldn't go so far as that. I called up a radio station a while back because my oscilloscope was showing a 45-degree line where the stereo scatter fuzzy oval should be. They thought I was a lunatic until I double checked by listening in my car. No it wasn't my equipment. And my scope is nowhere near calibrated. All their lab equipment was switched on the digital signal so they didn't notice the board on the analog side was switched to mono.

Meanwhile to add a possibly useful question to the thread. Is this the kind of step wedge layout used for testing?


If so, can you test with an offset, or 90-degree angles to your usual. Maybe you are seeing an effect where the outside edge of the film receives greater development than the center.

p.s. I work for Kodak, but not in film - here I am a hobbyist. The opinions and positions I take are my own and not necessarily those of EKC.