Quote:
Originally Posted by SkyWatch
While on-axis performance is critical for any eyepiece, for a non-motorised dob it is good to have a relatively wide sharp field, even for planetary viewing, because it gives you more time looking and less pushing and waiting for the vibrations to settle again. It is really annoying if the image worsens significantly when the planet moves off centre, and this is often the case for budget eyepieces.
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Only if your telescope is capable of delivering sharp images over that wide field, which Newtonian cannot, due to coma.
A 10" f/5 Newt will deliver "planetary" quality wavefront (~1/10 wave, ~1/30 wRMS or ~0.95 Strehl) over a field that is only a tiny bit larger than 1mm.
The only way around that is if you add Paracorr. Or, better, an EQ platform.