For the story i had a VMC 200L.It give me very good planetary views just a little behind my C8 XLT.
It have some good advantage : no shifting. the focuser is well made. No dew on the Schmidt corrector
but sometime need a dew shield too when humidity is heavy, like a newton.
Its a field-maksutov-cassegrain, so i find the coma and field curvature the same as a classic SCT.
It have some primary barrel problem. difficult to collimate because when you tighten the push-pull screws you can get strong astigmatism. But you can collimate the primary when dew. A SCT cannot be collimated in dew weather because you need to remove the dew-shield and then...
The collimation don't move like a SCT.
Now i sell it because i got a good price on the second hand market for a VC 200L.
Same primary barrel problem but once collimated i have now very good airy pattern. It was undercorrected but i take off a 3mm washer behind the secondary older and spider vanes and the view is now improved. Only minor undercorrection.
The big advantage with the VC 200L over the VMC 200L is the very wide flat field. No as vigneted as the edge. The drawback is a loss of contrast because of the 42% obstruction plus spider vanes.
The C8XLT is slightly better for planetary views. You can't have your cake and eat too !
Edited by jjack's, 13 September 2017 - 04:52 AM.