Last night, first light in the SW180 was hindered by thin high clouds gradually moving in from the NW about a 1/2 hour after I started. The OTA was set out at 41ºF 2-1/2 hours in advance to acclimate. It was 34º when I started. With that amount of "cooling" time, tube thermals were pretty well behaved but a star test showed the optics were severely over- or under-corrected (I forgot to ascertain which it was). So views were not very impressive. Since temps were still falling, I could only hope that the figure would improve later. In the meantime, I concentrated on getting to know the ergonomics, etc.
My fantasy of using an office chair for observing held good, except for objects within say 20º of zenith, which will require something lower. The ergonomics are much improved over the 6" F/8 frac it replaced.
The straight-through finder is good but I may replace it with a RACI/RDF combo next time out. Or maybe not - this will pretty much live on the goto mount, making the finder less relevant. Maybe an RDF only would do? What are other owners of this scope using?
Speaking of mount, the ASGT proved to be a very good match for the SW180.
This was my first time using a Mak, and hence first experience of "image shift" while focusing. It was quite pronounced. How much is considered normal for one of these?
My longest FL 1.25" eyepiece is a 35mm Orion Ultrascopic, which worked well with the scope and resulted in 77X magnification. I will probably be using that eyepiece a lot with this scope. The FOV is surprisingly small with it, and probably won't improve much if at all with my 2" 40mm Sterling plossl.
A little before 9pm the haloed moon was peeking up above the mountains to the east, revealing just how bad the transparency had become. I decided to call it a night, but first did a star test using Aldebaran, and took a quick look at nearby Uranus. The star test was much improved over the earlier one, patterns appearing essentially the same on both sides of focus. Phew. That was good to see. Collimation may be just a tad off, I'll check that out in more accommodating conditions. Set the goto for Uranus, put a 12.5mm in the focuser, and was greeted with a clearly-defined light blue orb at 216X. Stars in the fov were pinpoint.
All in: a) It's an enjoyable, easy-to-use scope, a high magnification specialist. b) I'm pretty sure I didn't get a lemon, and c) The image shift thing is really annoying and needs to be addressed.
Edited by precaud, 26 November 2018 - 09:26 AM.