I measured the emission spectrum of a tungsten lamp in the laboratory a few years ago. I don’t remember all the details, but in the visible spectrum the tungsten the amount or radiation that the tungsten lamp emits is roughly 0.3-0.4 times the radiation that a black body would emit.
* In page 151 it has a graph of the emissivity of tungsten for different colors and temperatures. More emissivity for blue (A) than for red (C).
* In page 156 it has a greph of the difference between the color temperature and the true temperature. For 3000K, the difference is only ~100K. I think that it’s changes the color only slightly.
* More friendly version, with an experiments with actual lamps.
* In page 525 it explains that the emissivity if tungsten at that temperature in ~0.42 but you must introduce a correction because the glass of the lamp absorbs a 8% of the light.
I googled a little and found these two articles:
1) http://articles.adsabs.harvard.edu/full/seri/ApJ../0061//000... :
* In page 151 it has a graph of the emissivity of tungsten for different colors and temperatures. More emissivity for blue (A) than for red (C).
* In page 156 it has a greph of the difference between the color temperature and the true temperature. For 3000K, the difference is only ~100K. I think that it’s changes the color only slightly.
2) http://physicsed.buffalostate.edu/pubs/TPT/TPTDec99Filament....
* More friendly version, with an experiments with actual lamps.
* In page 525 it explains that the emissivity if tungsten at that temperature in ~0.42 but you must introduce a correction because the glass of the lamp absorbs a 8% of the light.