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Old 29-04-2009, 03:38 PM
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gregbradley
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Quote:
Originally Posted by dugnsuz View Post
Thanks for the comments and info greg.

Using 10minutes as a rough starting point for my proposed Ha exposures and using Eta as an example, would I be likely to record enough detail with the 6nm and 13nm filters in this time?

Doug

Hi Doug,

The usual advice on narrowband is to do longer than normal exposures so the signal gets well above the noise.

I have done 10 minute subs and they worked fine. 15-30 minutes may be better from a signal to noise ratio viewpoint.

It becomes more critical with O111 and especially S11 which si very dim.

Ha isn't so bad.

Greg.
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