[argyllcms] Re: Absolute light meter calibration?

  • From: Marwan Daar <marwan.daar@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 12 Aug 2015 16:32:28 -0400

Do you accurately know the surface area of the filament? The emissivity is
only useful if you know the watts per square meter leaving the surface from
the temperature and the emitting area. In the bulb we have a certain amount
of emission which is caused by the input electrical power; but we would get
just the same from another bulb with half the emissivity and double the
surface area.

I think...

Either way, it seems that you can't assume that all the input electrical
power is converted into radiant flux. And if this is the case, doesn't this
defeat the whole purpose of using a filament + mathematics to calculate
radiant flux, let alone irradiance (the latter requiring knowledge of
surface area)?


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