The blue colored lamps (and flashbulbs) were designed for color film. They put out less light, and lasted shorter times (lightbulbs, not flash!) The clear ones were fine for black and white film.
Tungsten filaments break down at a lower Kelvin temperature than daylight (about 5600 degrees) Usually the best achieved was about 3400 degrees K.
Color film, usually balanced for the daylight spectrum would be very yellow with the clear bulbs. So either a special film made for tungsten lamps was used (as in Hollywood films) or a blue filter was placed on the camera lens. Although again it lost light throughput.
The blue colored lamps (and flashbulbs) were designed for color film. They put out less light, and lasted shorter times (lightbulbs, not flash!) The clear ones were fine for black and white film.
ReplyDeleteTungsten filaments break down at a lower Kelvin temperature than daylight (about 5600 degrees) Usually the best achieved was about 3400 degrees K.
Color film, usually balanced for the daylight spectrum would be very yellow with the clear bulbs. So either a special film made for tungsten lamps was used (as in Hollywood films) or a blue filter was placed on the camera lens. Although again it lost light throughput.