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Andre27
15-06-2015, 07:44 AM
Hi All
I fitted a new low profile focuser to my SW200p and added a GSO field flattener + 0.8 reducer, I used a Cheshire eyepiece & laser collimator to line up the optics.

There is now more coma than before,can anyone pickup from the attached image what else may be causing the comet like stars.

Thanks Andre

glend
15-06-2015, 09:13 AM
I would be curious about why you think you need a field flattener/reducer on a relatively fast f reflector?

All that is normally required for astrophotography (assuming DSLR) is a coma corrector (the Baader MPCC Mrk III would be my choice).

The scope will have coma without a coma corrector.