I was finally able to get out and do some observing. It's a pain that it gets dark so late, and in my area, it quite often clouds over just as it's getting dark this time of year. Anyway, I was able to use my leveling base and setting circle for the first time.
For my first object, I didn't need to use the setting circle. I pointed my scope at the constellation Lyra, centering it right between the stars Sheliak and Sulafat in my finder. I popped my 30mm eyepiece in and there was M57, the Ring Nebula. It was quite small, so I switched to my 30mm with the 2x Barlow and got a better view. Finally, I switched to my 8-24 zoom eyepiece. After a bit of experimentation, I found my best view at around 12mm. 8mm gave a larger view, but it got a bit too dim.
After enjoying that view for a bit, it was time to try out the setting circles to find my first globular cluster, M3. I went back to the 30mm and centered my scope on Arcturus. Checking SkEye on my phone, I found the altitude and azimuth, set the azimuth pointer on my base, and noted the altitude on my Alti-Gauge (which was off a little over a degree). I then found the coordinates of M3 and swung the scope to that locate. I didn't see M3 in my field, so I started panning around a bit. There it was, just outside my view, very easy to spot in the 30mm. Again I went to my 8-24 zoom and found 12mm was the best view. At that setting, M3 was still bright enough to see clearly and I was able to resolve many stars.
I tried for M92 and M13, but they were very close to the zenith and I didn't have any luck. I also tried for M51, but also no luck. I probably looked at it but couldn't see it due to the light pollution.
Speaking of light pollution, I tried a couple of different things to help out. First, I made a light shield for my
Apertura AD10 dobsonian telescope. I've read that this has made a difference for some people, but I didn't find any benefit from it myself. Here's how I did it if you want to try anyway.
The best paper I could find was black poster board from Wal-Mart. Other stores carried stuff they called poster board, but it was more like construction paper and was pretty floppy. The Wal-Mart stuff is quite thick and stiff. First, I laid out two sheets overlapping a couple of inches and aligned as straight as possible. Lay them out the long direction. I used packing tape on one side only to attach them together. As you can see in the picture, the paper is more dark grey than black and is kind of shiny. To cut this down a bit, I sprayed what would be the inside with flat black paint. I didn't put tape on the inside because it's shiny and painting over it would cause the paint to flake off into the scope, not a good idea.
Next, I measured around the circumference of the end ring of the scope, which came out to 38.5". I measured and marked the paper and that position, then cut off the extra a couple of inches past my mark. I put tape along the edge that will be the bottom of the tube to reinforce it. I then rolled the paper, lined up with the mark, and used more tape to complete the tube.
This light shield slips over the end of the scope and stretches very slightly to slip over the four mounting screws for the spider, giving a very secure fit. Look through the focuser without an eyepiece and you can see whether it's obstructing the view at all.
I tried the light shield, and to test whether it made a difference, while observing M3 I pulled off the light shield. I couldn't discern any difference in the view, contrast, or background with the shield on or off. I also tried looking at some objects when I was facing my neighbors yard, where they have a very bright patio light. Still no difference. It may work better if I actually flocked the light shield instead of just painting it, but I don't know if I'll bother with that. I would like to flock my scope tube at some point, hopefully that will help.
Notice that when the light shield is on, the end of the scope is covered so you can't grab it to point the scope. To deal with that, I installed a nice "comfort grip" knob.
I used part
60975K75 from McMaster-Carr. This is a 1.5" diameter round knob with a 1/4-20 insert. The knob is positioned below the spider mounts so the light shield fit properly. To drill the hole, I laid the scope tube flat, masked off the area to catch all of the scraps, and carefully drilled a 1/4" hole. I vacuumed the scrap out after drilling. Make sure none of scrap falls down to the mirror. I used a 1/4-20 stainless bolt, two washers, and a nylon locknut for mounting. I painted the head of the bolt and one of the washers flat black before installing.
Although the light shield didn't help as I had hoped, I did find another suggestion online that is a bit benefit. Some people throw a towel over their head to block out stray light (insert Hitchhiker's Guide To The Galaxy joke here). This works ok, but is a bit awkward. The suggestion I found was to use a dark T-shirt, slip it over just your head, then pull it up over they eyepiece to observe. This worked very well, especially when I held it closed under the eyepiece as well, to block out reflection from the ground. I had to be sure to leave some opening though, otherwise my breath would start to fog the eyepiece. I am thinking of a design to deal with this. I'll post it if it works out.
