[argyllcms] Re: Absolute light meter calibration?

  • From: Ben Goren <ben@xxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 10 Aug 2015 14:55:54 -0700

On Aug 10, 2015, at 2:39 PM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:

So I have my doubts that a do-it-yourself approach is worth more than relying
on
how an instrument was factory calibrated, because what is the worth of such a
calibration if you have no way of verifying the reference ?

I've been drifting towards that conclusion. I had thought there might be
something from first principles (or a reasonable facsimile thereof) that could
be adapted, such as a bulb that measures so many watts consumption will produce
so much light -- similar to how easy it is to do a spectral calibration with a
cheap compact fluorescent bulb and knowledge of the mercury emissions spectrum.

Over the weekend I found a US Geological Survey researcher who supplies
reflectivity spectra of the Moon to satellite operators who can likely get to
me date-and-location-specific data that'll let me use the entire Moon as a
calibrated color target, which is exactly what I need for the project that
sparked the exercise.

I still might play around with Richard's suggestion of a bolometer, but likely
not for calibrating light meters.

b&

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