Quote:
Originally Posted by tonybarry
I recall asking the question here - how does one do a "colour balance"? when it's not possible to see the object one is imaging (or see it only very faintly?)
The best answer I got was to do a colour balance on a star which has a known spectral hue (e.g. Betelgeuse for reds, Rigel for blue) ... which does offer some kind of a reference white (or colour).
It is partially for this reason that I think the OSC (one-shot-colour) cameras for astro work may be more reasonable items to use, even though the Bayer Mask does cut down the light intensity considerably.
I hope you can continue your thinking on the subject, and look forward to your thoughts.
Regards,
Tony Barry
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Tony,
it's best to try and calibrate your OSC and/ or mono cameras+RGB filters
on G2V stars. This is the only way you can get the RGB mix even
close. Meade filters will give different G2V calibration settings to
Astronomiks etc. Because CCDS are much more linear than emulsion
film, once this calibration factor is known and set, then your colour
balance should be a reasonably close approximation to true colours.
Another annoying thing is atmospheric extinction. If you take your
RGB set low in the sky, the blues will be affected most by this. FWIW.
Steve