William writes:
<< Gary Reese has measured film reflectance, and I have a question for him. As
film is exposed to light, the silver halide slowly breaks down into metallic
silver (or undergoes other chemical changes). (You can see the darkening this
produces by exposing the "tongue" to light for a while before loading the
film.) This change doesn't occur rapidly, but I was wondering whether Gary
measures reflectance "promptly" after pulling the film from the canister. >>
You bet I accounted for that. I measured with a Sekonic 1 degree spot meter
on freshly exposed to the light film surfaces.
Makes for a good argument to advance the film just prior to exposure. That
will result in more consistent (don't read accurate) OFT exposures.
I'll be visiting Olympus America in the next few weeks and will bounce the
question off them of what the baseline reflectance is for setting OFT exposure
calibration. I can just hear John H. telling me "they won't know" :-)
Gary Reese
Las Vegas, NV
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|