I am looking for a transparent calibration grey scale to calibrate a densitometer
Alternatively, a dark piece of film about zone IX with an accurate density reading so I can set up my Eselite densitometer to check on zone VIII to aid keeping my deep tank of D76d in good working order
Since 1985 I have done this by guestimation, but now I have a densitometer I want to do it properly
I've used cutup pieces of gelatin neutral density filters for calibration. Probably some film base vs. filter reason this may not be 100% accurate. But my spot metering isn't either.
Make sure you get a calibrated step wedge. They will mark the actual values for each of the steps, and then you can check your densitometer at more than one value.
If you really don't want to spend the money, shoot a test frame and mail it to me and I'll read it for you. Send it with a self addressed stamped envelope and I can get then get it back to you. Or just cut it in half and mail me one half. The other should be very close. PM me for my address if you want to go this route.
I use the Stouffer gear with good results. They're very helpful if you phone them and might help you avoid something that isn't ideal. My old Macbeth TD902 calibrated with the calibrated Stouffer agrees right on with a Wallner unit (amazingly consistent) that I also have.