Friend of mine just bought the Meade 5" refractor on LXD75 mount. Mount stopped working quickly..."motor error" message...but scope is also soft on planets and he was disappointed with image.
Used 9mm Nagler to star test out of focus. With filters (green, red, yellow) result is all the same: inside focus rings are crisp but diffraction image is out of round, flat spot on one side and overall oval. Out of focus rings are very indistinct, no contrast, barely visible, but diffraction image more round. I've star tested a handful of scopes (reflectors) and the difference in image in and out of focus seems enormous compared to those.
Without filter, violet is outside rings when inside focus, with rings uniformly yellow. Outside focus, a violet core is present with the outside rings yellow.
Does it make sense to mask it down to a 4"...big turned down edge possible?
Seeing was not great. Could not see in-focus rings.
He bought it from OPT but they apparently just ship it directly from Meade factory...?margins not high enough for this scope.
With this info, any idea what problem is....should he send scope back too? Can a pinched lens do this much? I know the achromat won't handle violet well, but the loss of contrast out of focus seems excessive, ?chromatic aberration also?
Used 9mm Nagler to star test out of focus. With filters (green, red, yellow) result is all the same: inside focus rings are crisp but diffraction image is out of round, flat spot on one side and overall oval. Out of focus rings are very indistinct, no contrast, barely visible, but diffraction image more round. I've star tested a handful of scopes (reflectors) and the difference in image in and out of focus seems enormous compared to those.
Without filter, violet is outside rings when inside focus, with rings uniformly yellow. Outside focus, a violet core is present with the outside rings yellow.
Does it make sense to mask it down to a 4"...big turned down edge possible?
Seeing was not great. Could not see in-focus rings.
He bought it from OPT but they apparently just ship it directly from Meade factory...?margins not high enough for this scope.
With this info, any idea what problem is....should he send scope back too? Can a pinched lens do this much? I know the achromat won't handle violet well, but the loss of contrast out of focus seems excessive, ?chromatic aberration also?
