Quote:
Originally Posted by DaX
So am I right in assuming an ideal color temperature is between about 4700K and 7200K? Is there a downside to using a more "white" and less "yellow" bulb? More energy consumption?
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"Ideal" is a matter of preference.... If you're used to incandescents, you want a cooler (more red) light -- a 100W incan. puts our a temperature of 2870K, but when it blows out - that flash is hotter (more blue in color because the filament is a lot hotter while it breaks apart):P So somewhere around there for a CF bulb. Fluorescent light temperature is different than that of a incandescent bulb - that wiki you linked to mentioned black bodies (perfect emitters) of which a fluorescent light is not (and doesn't follow the color temperature scale exactly).
If you want to mimic sunlight (which is different than daylight mind you) -- that greatly depends on what time of day and your latitude and the season you want to mimic. But that range is around 2000(sun rise/set)-5400K (summer - noon). Daylight - which takes into consideration the sun+sky ranges from 2000 (sky doesn't add much at rise/set)-6500K. And finally, color temperatures rise in the shade - that is, no direct sunlight.
Now this probably is really confusing.... but here's the last bit... CRI - Color Rating Index. CF bulbs are not black bodies -- that is, they do not emit all the time. In fact, they are operating at twice your mains power frequency cycle and are off two times per cycle! During that cycle, power is not constant - so the color temperature emitted changes with time - at twice your mains power frequency. So for those of us operating @ 60Hz (most of us) - our lights cycle at 120Hz.
Now, back to CRI. The CRI equates a non black body light source to a black body light source. The scale is from 0-100 - 100 being the black body - perfect color temperature representation. But, this comparison only works to compare two sources of the same representation. So if your bulb selection includes a CRI index, pick the color you want and then pick the highest CRI
Mind you, 6000K with a 70CRI may not be better than a 5000K with 60CRI - temperature is key.
So my final point is - the best bulb temperature is a personal thing. For a reference, commercial/professional daylight photo flood lights are 4800-5000K - which is where I'd like my lights to be
6500K is another common temperature and a lot of home-use (that is, not professional) electronics are calibrated to this color temperature. It's likely your P&S camera is default at 6500K
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Hopefully I didn't scare anyone
You can learn all this by reading photography books and such :P But picking the "right" color isn't too hard. And if it's really bad, you can always return your bulb and you'll know - yes, I need more blue (hotter light) or more red (cooler)