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Old 05-03-2012, 01:18 AM
Poita (Peter)
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Join Date: Jun 2011
Location: NSW Country
Posts: 3,586
Quote:
Originally Posted by DaveM View Post
The similarity in price between the dedicated scopes and front mounted filters is due to the fact that the dedicated scopes use a smaller (and therefore cheaper) internal etalon. The trade off with the internal etalon setup is that you may have a 'sweet spot' that is on-band while the outer margin of the view may not be, and thus not showing the same detail in this area. The degree to which a sweet spot affects the view varies between scopes and owners of the Lunt80 suggest that this is not much of an issue with that particular scope.

I own a large aperture h-a scope, but the 60-80mm aperture range seems to be a good spot to be in terms of resolution, price and portability.
Its a shame the 60mm external etalon couldn't be used as an internal one and then fitted to a 130mm acro or similar

I'm leaning strongly towards the Lunt now I must say.
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