Imaging Uranus and Neptune
I am in a suburban location so light pollution is an issue. As a result, I'm looking at shifting my imaging focus away from DSOs to planetary and lunar. I'm using a combination of scopes and cameras and looking for the best combination I can achieve with what I have.
I have a 10-inch astrograph (with a Suchting conical f3.8 mirror) and a North Group ED127 refractor. Both have roughly similar native focal lengths although the refractor is a f7.5 scope and the oother f3.8.
I don't see much future in using conventional CCDs (such as SBIG and StarlighXpress) but plan using ASI290MC as a dedicated planetary cam using either SharpCap of FireCapture. Whichever scope I use, I'll have to include my x2 Barlow. Although I do have a GSO x5 Barlow as well but I think that will be difficult to use in practice. But boith scopes have their down side: the f3.8 will have a fair bit of coma and it isn't practical to use a barlow with an MPCC; and the refractor is going to have some CA despite being flogged as a triplet.
My question therefore is what others are using to image these two planets.
With Uranus at only 3.3 arc-seconds and neptune a bit less, I'm going to struggle to get any decent image scale with just a x2 Barlow - the ASI290 has an image scale of 0.31 arc-secs/pixel and the refractor something similar.
Any suggestions to improve on these numbvers?
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