Quote Originally Posted by Bill Burk View Post
Yup. That's the best densitometer: a print.

Densitometers just try to estimate the printing effect, and you hope there is some correlation between the estimate and the result.
Yes, if you just want to use the densitometer for process control, you probably don't need any exact filter. Just read the negative the same every time. Say, for example, you have a Pyro negative of your typical subject that was processed with a development time determined by trial and error, such that it prints well around grade 1.5 to 3. Then process a control strip with those same conditions and see what the gamma is. You can check it with all 3 colors and document this as your baseline.

In the future if you prints are not coming out right, you can re-check a control strip and see if the color (stain) or gamma has changed from your original control.