Does anyone know a source of blue lightbulbs in *low* wattage? I don't want powerful "photoflood" bulbs with a blue coating, just regular low residential wattage (60 watts or so) bulbs with higher than normal tungsten color temperature. This is for 4x5 chrome work where light will be mainly windows and pack&head strobes but numerous regular lamps form part of the decor and I want the lamps to be illuminated without going deep amber. I guess the other alternate is to make sleeves of Roscoe acetate filters and slip them over existing bulbs.
GE makes medium base light bulbs under the brand "Reveal" with higher than normal color temperature. I could not find the Kelvin rating on the bulb, but they are much cooler than a standard light bulb.
If you can find a rental house with some old stuff, you might be able to rent a Colortran unit.
They were very popular thirty or forty years ago. We had several in the studio for years. Basically a transformer about the size of a car battery, having a rotating switch for various levels of output voltage.
The idea was that regular household bulbs could be used instead of expensive photofloods. As you know, photo bulbs are manufactured to run on 60 or 80 volts. When you plug them into normal 110 volts they burn brighter and bluer.
The same effect was achieved with the Colortran unit. Normal bulbs were burned at 110 volts as modelling lamps. When the final exposure was made, the Colortran unit was cranked up to 120, 130 or perhaps 140 volts to get the proper Kelvin temperature for Type B color film. As soon as the exposure was made the unit was turned back down to extend the life of the bulbs.
I suppose if you can’t find an old unit, something like this could be made up fairy cheaply.
Just another historical tale from the Old Duffer...
As another old duffr responding ..... Colortran units (and othr similar) are actually still manufactured. Meanwhile, you can find them very reasonably on eBay all the time.
Another answer iw to make 'shades' out of #10 cans and gel the end of the can with the right rosco gel.
Dave, thanks for the "Reveal" brand lead. I'll look for it and get color temperature readings.
The Colortran is interesting but sounds like it would increase light intensity, which I don't want, and might not work for trying to change the color of four or five different fancy little lamps scattered around a fancy country Inn suite of rooms.
Maybe "wraps" of 1/2 CT Rosco filter material will be the answer, but relamping seems simpler if I can find the bulbs.
Try artists suppliers. They usually keep 60 and 100 watt versions. They are usually refered to as "daylight" bulbs and are used by painters to reproduce natural daylight for painting in the darker months. Unlike blue coloured bulbs these are colour matched to about 6000 degrees K.
These are also the best way to view colour prints if a good northlight is not available i.e. in the darkroom or at night.
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