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Mike,
Good luck with your film investigation. I can
answer a couple of your questions, but not all of them.
You can compare films by scanning and reading the
intensity with a computer. I use this technique using the Info tool in
Photoshop. The scanned readings don't relate exactly to calibrated
densities, but will give you a relative comparison of films and exposures.
You have to be careful when scanning, to use the exact same settings on the
scanner. Many programs, such as Vuescan automatically make exposure
corrections to give you the "best" picture, which is what you don't want.
If you are taking the film somewhere else to scan, you may run into
this.
I'm not sure how well your testing the hypering
effect will work with a gray card exposure. Testing reciprocity with light
that is a different wavelength from the sky objects may give you mixed
results. Most nebula are H=alpha, with reflection nebula in the blue-green
range. Stars, Clusters, and galaxies have a wide spectrum. I have
found with color films (and my own Tech Pan tests) that the reciprocity
varies for the various light wavelengths. You can see my test
data and my test procedures at http://home.nethere.net/mpd/FilmTestData/FilmTestData.htm
Contact me direct if you have specific
questions.
Clear Skies,
Don |
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