Quote:
Originally Posted by Matthieu
Thanks Morton,
That opens another can of worms 😅 as the sv503 is available at 102mm and ES has the AR 102 that also looks enticing.
If I understand correctly, provided I have the right eyepieces, the 90mm sv48p should outperform the sv503 80mm.
What would I need to look for in widefield eyepieces for faster refractors? I assume it’s not so much about coma so is it about field curvature so ultra flat field eyepieces would help?
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Field curvature is actually dependent on focal length, not ratio. The Svbony 90mm and the Star Travel 102mm both have focal length of 500mm so FC will be the same. Where focal ratio comes in is the faster the scope the steeper the light cone arriving at the eyepiece. Complex designs like Naglers and the ES82's generally handle this better.
I've read that the ultra flat field eyepieces actually work best in flat field scopes so not sure how they'd fare in a short refractor. You might need to Google that.