[argyllcms] Re: DIY reflective spectro
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sat, 11 Mar 2006 22:05:52 +1100
Rene Bartsch wrote:
1.) Light sources:
LEDs are quite stable on their wavelength/intensity
I'm not so sure about that. "white" LED's may have a fairly strong
deep blue content, that could potentially cause Fluorescent Whiteners
to react a little differently to more normal viewing light sources.
Hints from some of the LED backlit LCD screen manufacturers point
towards LEDs needing temperature compensation to ensure consistent
light output (or some sort of feedback element.)
2.) Calibration:
How about a set of laser diodes with several wavelengths as reference?
It depends on how consistent laser diode wavelengths are. Some information
I came across indicated that ordinary LEDs have manufacturing variation
in the dominant wavelength, so laser diodes may have similar variability.
Are there similar sensors for color and brightness (or are there sensors
providing
a freqency dependent on the value which can be interpreted as bitstream)?
Most instruments depend on the assembly of the raw components (such as
sensors & filters), and then need some sort of calibration to take out
the manufacturing variability of the components. I'm not sure
you'll find many integrated color sensors that come with any sort
of "calibration" information.
4.) Laser interference:
Is it possible to interpret the interferences of a laser as colour or brightness
(like a laser metre does with distance)?
I'm not sure exactly what your idea is here.
Graeme Gill.
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