Seth Baldwin Posted May 19 Share Posted May 19 I'm trying to test the spectral sensitivity of an expired Kodak motion picture stock. How would i achieve this? Would i expose the film to isolated wavelengths at a single exposure value to see how each dye in the film responds after development? Quote Link to comment Share on other sites More sharing options...
Sergey Surin Posted May 21 Share Posted May 21 We have such kind of service Here in Moscow (laboratory of Mosfilm company) , I used it two weeks ago, they took 10 meters from each roll (in completely dark conditions) i gave them and then they made full check wth all information about how it holds in terms of sensitivity/dynamic range / fog level (hope I translate it right) And it seems that it could be done in every film developing laboratory all around the world so you just need to ask about it 1 Quote Link to comment Share on other sites More sharing options...
Giray Izcan Posted May 21 Share Posted May 21 It is called snip test. Quote Link to comment Share on other sites More sharing options...
Seth Baldwin Posted May 21 Author Share Posted May 21 I've already done a clip test to establish dynamic range. But I want to find a way to test the individual sensitivity of each dye to particular wavelengths of light. Quote Link to comment Share on other sites More sharing options...
Sustaining Member David Mullen ASC Posted May 21 Sustaining Member Share Posted May 21 Wouldn’t you also need a light meter that was accurate for specific wavelengths? Quote Link to comment Share on other sites More sharing options...
Sustaining Member Phil Rhodes Posted May 21 Sustaining Member Share Posted May 21 For this you'd need a monochromator, which fires a beam of light through a diffraction grating to split it up into the spectrum, then passes the resulting light through a slot to select just one colour. The slot may be variable width. Given a sufficiently broadband light source (incandescent bulbs are widely used) light of any wavelength and bandwidth can be created. Monochromators are usually metered using a photomultiplier-based detector. Quite whether it would be reasonable to apply all of this to testing suspect film stock is another matter. 1 Quote Link to comment Share on other sites More sharing options...
Seth Baldwin Posted May 21 Author Share Posted May 21 (edited) 3 hours ago, David Mullen ASC said: Wouldn’t you also need a light meter that was accurate for specific wavelengths? Yeah, I'd likely need a spectrometer from Sekonic, can rent one thats fine. Or what phil said sounds promising. Edited May 21 by Seth Baldwin Quote Link to comment Share on other sites More sharing options...
Sergey Surin Posted May 23 Share Posted May 23 If you meant individual sensivity of each part of the spectrum (Red/green/blue) a have them too Quote Link to comment Share on other sites More sharing options...
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