Hi §AB,
§AB wrote:
"I think the flocking and dewshield played a major part in making these objects, which are at the absolute limit of a 10", visible from my suburban backyard."
It undoubtedly played a role, but much more importantly you are also using what I think is a "just right" exit pupil for maximum contrast on low-contrast, small deep-sky objects -- about 1.5 to 2mm. At x146 the ep is 1.71mm and at x192 1.3mm.
My old 10" was "flocked" too. I read about the idea in the US magazine "Amateur Astronomy". Black flocking paper wasn't so easily obtained then so following the article I went to a haberdashery and bought 1.2m of German black cotton velvet.
Ordinary acrylic velvet is real shiny compared to this stuff which was about $100 per metre last time I looked and hard to find too. But it is _amazing_. Spread it out on the loungeroom floor and it just looks like a big black hole -- a void. It seems to swallow light. After taking some advice at the hardware, I used an epoxy glue to stick it on the inside of the tube. I rolled the velvet up on a long broom handle, painted a section of the inside of the tube with glue, laid it down using the broom and rolled it on like wallpaper smoothing it with hands. Paint the next section with glue, roll it down, smooth it out, paint the next section, roll it down, smooth it out etc etc. I did a really good job of it with only a couple of low bubbles here and there.
When my wife and I went to get up off the floor after having done the job, we discovered we were both stoned on the glue because we spent so much of the time with our heads in oppposite ends of the tube smoothing out air-bubbles! (true story). Co-incidently, this was the same experience the guy who wrote the article had, but I overlooked as a consideration.
When it came time to do the 12", I used wallpaper glue which also gave a good (but less intoxicating) result.
§AB wrote:
"So in theory, at a truly dark sky, my scope could pick out 15th magnitude stars and small concentrated galaxies similar to 5291/MCG -5-33-5."
I can't think of any reason it/you wouldn't. I believe the faintest stars I could (reasonably easily) detect with my old 10" were about 15.2 and galaxies with SB magnitudes a bit worse than 14 is about the limit in a truly dark sky. But don't accept my word on that -- push for your own limit because you just might do better.
§AB wrote:
"Man, I'm completely hooked on galaxy hunting now! I had no idea it could be so rewarding!"
Know the feeling!
But remember, there are many other equally big challenges out there, particularly in the G.Cs and PNe. On that front, I think you might find the Jul/Aug 2008 AS&T Deep Sky Delights will be interesting!
Best,
Les D
Contributing Editor
AS&T