If this won't cure my SAD, what will?

[fivemack]

This is the 85W-from-socket 425W-incandescent-equivalent-power lightbulb that I bought to see whether it would make me happy.

For size comparisons, that is an Apple smallish keyboard, a real apple and a real kiwifruit. The fruit are normal-sized examples of their ilk, and the bayonet on the lamp is of the standard size.

Comments

[fivemack.livejournal.com]

My suspicion is that the colour temperature is written on the pots that the phosphor comes in, and carefully transcribed by someone at the bulb factory. Using an improvised spectroscope made out of a David Attenborough DVD and the corner of an envelope, it's clear that this particular bulb is emitting in about five fairly sharp lines: bright green and red, a fainter yellow, somewhere cyan-ish a bit fainter than the yellow, and faintly somewhere in the deep blue.

Traditional incandescent light bulbs are somewhere between 2000 and 3300K, halogen ones are a bit higher brightness. Peak lambda is inversely proportional to temperature and something like 2.9mm / (temperature in kelvin) so is somewhere in the IR for all incandescents.

If the filament is behind coloured glass, its spectrum will be very non-black-body and I'm not sure how the colour temperature is then defined - for instance, at no temperature will an incandescent object look apple-green, the spectrum's just too broad.