OPTI 200 Lecture Notes - Lecture 5: Bromine, Color Temperature, Tungsten
30 Aug 2018
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Tungsten -halogen lightbulbs tungsten filament, trace amount of halogen vapor, iodine or bromine, bulb made out of fused quartz, tungsten deposited back into filament (halogen cycle), longer lifetime of the filament. Tungsten lightbulbs are about 10% efficient of optical power other 90% goes to heat. Newer incandescent lightbulbs get more lumens (light) out for the same electrical power. Double coil helps maintain a higher temperature inside of the lightbulb. 1 watt= 1 joule / 1 sec. 100 w incandescent bulb emits 1700 lumens. Low temperature to the left will look warm/yellowish, the light looks more cool the more blue it has in it (color temperature) We should make all of our lights green because our eyes are the most sensitive and it would look brightest if everything was green; it"d be very efficient. Things would look very different under green light. If something is luminous it gives off a lot of visual light we can see.
