Quote:
Originally Posted by saysme
Hi guys this is a stack of 4 images taken last night to test my 10" GSO I have added felt to the tube from Prostar and collmination springs from Bobs nobs. I have a GSO Coma corrector insitu and the scope was collminated with the Coma corrector in. The image was taken prime focus with a 600D focused on the moon. Could someone tell me the sequence of hardware they are using and if this amount of coma is typical for my setup, and how to correct it please.
My hardware setup is, Focuser, 35mm extension (required for focusing), coma corrector, Coma corrector to eos adapter, eos adapter, Camera. Thedistance from the coma corrector to the camera chip is 60mm +/-.
Also there is what I think is reflection at 2 oclock from Altair, which featured in all photos from this run which did not appear in my other photos, would appreciate any thoughts on this to.
Thanks heaps
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I assume your scope is a newtonian, not a RC or something else.
Two things:
1. not all coma correctors are created equal. Is the GSO one you're using suitable for your scope? Can you borrow a Baader MPCC from someone to try it out?
2. Do you have the backfocus for your coma corrector set correctly - i.e. distance to the image sensor. This varies from one coma corrector to another. Since you're using an EOS camera with a T-Ring, yours will be working at about 55mm (i.e. 45mm in the camera and 10mm in the T-Ring adapter). This is right for an MPCC but may not be right for a GSO, for example. Can you check this?
And yes, there is uneven distortion in that image so you may have more than one factor working there. If your scope is a newtonian, is it properly collimated?
Peter