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Old 10-12-2009, 08:16 AM
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toryglen-boy (Duncan)
Scotland to Australia

toryglen-boy is offline
 
Join Date: Jan 2009
Location: Canberra
Posts: 1,645
QHY8, Coma, Reflections, and the MPCC

So, i get bad coma on the F5 scope when taking pictures, and i use an MPCC, although i found it tricky to get the spacing right, so i ordered the QHY8 MPCC back focus matched adaptor from Peter Tan, and although its machined very nicely and fits, but i still get coma, even though i am using the right spacing (55mm)

Also, i get really bad reflections of the colimation marker in the primary when i use the MPCC, and i mean REALLY bad, any brightish stars in the image, produce a red doughnut, right next to it.

Have any of our QHY8 and MPCC users managed to do anything about getting the right spacing, and getting rid of reflections?

thanks
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