Digital BW, The Print

I am fooling around with a used X-Rite 811 transmission/refection densitometry I picked up on eBay and I have a couple of questions for any experts on sensitometry lurking out there.

 

In reading reflective density of inkjet prints there is the issue that the paper is not completely opaque. You can see light though even the heaviest papers we are using. So when measuring image density the print being measured needs to be backed up with an opaque material. My question is should this be white, as in stacking up several pieces of paper under the print or should it be black? My inclination is to use black so that no light that passes through the paper gets bounced back, since this would logically seem to falsely increase the reflectance and lower the density reading. The calibration plaques are enameled metal so I assume the instrument expects to see a 100% opaque reflective target.

 

Dumb question: How do you convert RGB densities to CMY densities or do they simply equal their color opposites?

 

The 811 has two transmission modes, one for E-6 and one for C-41. Which would be the best for standard developed B&W film? Which mode would be best for yellow/green stained pyro developed B&W film?


Martin Wesley

http://www.borderless-photos.de/guests.html




[Non-text portions of this message have been removed]