[Stephen Benskin]

Funny enough, I was planning on doing something very similar, so I sincerely hope that you don't lose your interest in this project or let others discourage you!

I have some related questions, too:

- Is it really possible/feasible to 'translate' the zone system into an 11-step scale from 0 to 255, defining zone V as 128 (or 127)?
- Assuming I have the stuff printed on matte paper, and I would take not to put the test target into bright sunlight, would this mitigate the issue of reflectivity?
- What about subject and print luminance range? Is it by principle not possible to print 10+ zones, even digitally, in a way to capture them as 10+ zones on a negative?

thanks,
sewarion

edit:

- and while being at it, would it make sense to consider any 12%/18% gray issues for metering etc.?

There are a lot of issues to consider. Basically, most of the testing is to find an EI and not the film speed. As such, you really don't need to be precise, but to do any kind of proper testing, you need to understand what you are testing for and the variables and conditions involved. A beginner creating thier own testing procedures really isn't the most practical approach. You're attempting to reinvent the wheel without understanding what it is.

Ten subject Zones equals ten stops or a log luminance range of 3.0. Glossy paper has around a maximum of log 2.0 relectance range. Matte paper has less. If you want to use your own scales, have them measured and use those measurements to compare with the finished print. Personally, I would recommend testing the film using a step tablet, and don't get caught up thinking only in Zones.