A photo analyst's nightmare

[spookyphoto]

Recently I've been thumbing thru a calibration manual for a Kodak 1B model IV and the MTL Star sensitometers. Both of which I have used and calibrated in my previous life. Both units were in the $ 250K range and are considered the finest on the planet. I've selected some pages to post that I think some people here might be interested in. In the table of contents you will see the steps that are taken. In looking at all the pages that I posted make sure you read the file name "scanned image last.jpg. This is the worst nightmare that a photo analyst can have. After all the calculations and calibration steps the last line reads "Conclusions: Differences between calculated and measured values cannot be accounted for. ASD/ENAML photometer may be in error." Ouch

All measuring instruments are NBS traceable. This brings up the old chicken and the egg problem.

How do you calibrate a bulb ? With a spectrophotometer and photometer.
How do you calibrate the photometer ? With a calibrated light bulb.

Special thanks to Kino for giving me the manual.