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Old 25-04-2010, 11:23 AM
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JohnH
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Join Date: Feb 2005
Location: NSW
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Quote:
Originally Posted by Hagar View Post
...Sensitivity may be a little less with the OSC using NB filters but this can be reduced using longer subs.
I have not used a osc with nb but I would be surprised if it is only a little less sensitive. For a given pixel size a osc is going to need ~4 times the exposure length for the same result is it not?

Most bayer masks are GRGB thus, with Ha in line, the GGB sub elements will all get zero photons (ok 1-2%) and you get 1/4 of the signal per pixel and I do not think the debayer routines will help compensate for this.

And while you can compensate with longer subs the exposure lenghts required in NB are already long, typically an hour or more per filter for me so taking that out to 4 hrs would be unrealisitc. My scope is small though so if you are 200mm or more it might be useable.
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