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Old 29-10-2011, 09:32 PM
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Peter Ward
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Join Date: Dec 2007
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Quote:
Originally Posted by philiphart View Post
I did this test awhile ago:

http://philhart.com/content/qhy9-vs-astro40d

Phil
Sorry Phil but I suspect you analysis is flawed. You are comparing 23 units of flux vs 15 (and even that isn't correct...but I'm lazy and couldn't be bothered with the math )

In terms of time to get data, then certainly things get a little muddy.

But in terms of spectral flux hitting the sensor its pretty straight forward.

The performance of CCD's, particularly with low flux, is significantly superior....as is their read noise.

An easy acid test is narrow band.

Expose, say 5 minutes, with an SII filter with a DSLR, then do the same with a mono CCD.

London to a brick you'll have usable signal with the CCD, but the DSLR will be mainly noise.
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