Quote:
Originally Posted by AlexN
I'm looking at upgrading to the TS OAG9 from Teton Telescopes in America. It only takes up 9mm of backfocus, so I could easily fit it between my CFW and my flattener. This would provide me with a full field of sharp round guide stars....
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Alex I have one of these units and am not overly impressed. Sure they are very thin but have no provision for rotation if placed directly after the FW (yours would be worse then mine). Once you fit them they are stuck and you have to turn the whole focuser to find anything worth using. The light path is also severly restricted with the aperture from the prism to the camera (hole through the stalk to mount guide camera) being about half the size of the QHY5 chip. The focus mechanism is fairly rudimentry to say the least and unless you really really really tighten it will allow the guide camera to flop about. As with all things both good and bad are present.
Mark