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Old 16-09-2017, 03:07 PM
DJT (David)
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DJT is offline
 
Join Date: Nov 2011
Location: Sydney
Posts: 1,452
Hi Jeremy

I agree with Greg. I have a "budget el cheapo" RC8, no flattener and guide with an OAG. You won't get pinpoint guide stars as you are picking off from the edge of the field where curvature is more noticeable. The curvature is a feature. The flattener is just extra glass that gets in the way.

Still I have no issues guiding long exposures for NB on dodgy looking guide stars but I do pick them from the lower edge of the auto guiding sub where the shape is less Leary when I can. Suggest you give it a go.

Note you are not seeing Coma.

The scope does need to be well collimated though, like any RC.

Enjoy

Last edited by DJT; 16-09-2017 at 03:19 PM.
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