Aging tungsten light characteristics?greenspun.com : LUSENET : Large format photography : One Thread
I'm noticing a dramatic increase in contrast put out by my tungsten bulb, combined with a decrease in intensity. Given the age of the bulb (2+ years), its a matter of time before it blows. Does anyone know if tungsten sources begin to shift toward "magenta", or know what exactly is occuring in the aging process? Just curious. Thanks,
-- Chris Jordan (Boston) (firstname.lastname@example.org), June 06, 2002
When it is time to change the bulb in your enlarger, it does have a tendency to shift to the red/magenta side. At work we have a system for all enlargers to talk with each other called the R System. We monitor everyday due to the differences everyday.... Chris, we change bulbs sometimes every 4 months due to the R values drastically getting different. As the bulb burns out it will get warmer (going to the red spectrum). When this happens, you will be fighting a loosing battle with no consistency later when reprinting if you keep track of your color numbers. Get a number of bulbs and have them on hand.
-- Scott Walton (email@example.com), June 06, 2002.
That makes sense. Thanks!
-- Chris Jordan (Boston) (firstname.lastname@example.org), June 06, 2002.