No Subject

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

Mike Canter wrote in reply to Mark Dottles question

>Photographic quality halogen lamps will produce 3200K .  Lamps can (and do)
>vary somwhat, however, and the "work lamps" you indicate may not be exactly
>3200K.

They certainly do seem to vary quite a lot the 12 volt halogen bulb for our
photoplan photographic microscope at work is  3,300K at 12 volts but can be
over-run to about 14 volts to give 3,600K. While our Gilert and Sibert
microscope suggests 3,325K for the same voltage halogen bulb.
 My old photography notes say that a difference of 150K to 200K is enough
to a show a cast in the final result so 3,300K should be OK with 3,400K
photoflood film and 3,200K with photopearl.         P.J.Homer



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