Fancy scope options

Keep thinking about buying a big fancy new telescope. I know it’s foolish to spend $2000+ on a hobby I barely do once a month, but shopping for gear is fun. Here’s what I want:

  • Something very easy to set up. If it takes 30 minutes to polar align, I’m not going to use it.
  • Computerized Go-To. Programmable, at that, with an open interface. The SkySafari SkyWire compatibility list is useful here as is the expanded list for SkyFi.
  • A mount capable enough to do guided hour+ exposures. The advice I’ve gotten means that means I need an equatorial mount, the cheaper alt/az mounts just aren’t accurate enough to hold a long exposure. Some possibility a double-fork alt/az mount might work (Meade LX or Celestron CPC) with a wedge mount.
  • Optics: ??? Honestly no idea. I want something that will make it possible to do astroimaging, hopefully with DSLR prime and/or a high quality webcam. I need to understand focal length and speed and that stuff before buying anything.

Possibilities in the ~$2000 range:

  • Celestron CGEM or CGEM HD. Equitorial.
  • Celestron AVX: Equitorial, lighter than the CGEM.
  • Celestron CPC. Dual fork alt/az option.
  • Meade LX90, LX200. Dual fork alt/az.
  • Meade LX80. Funky multi-mode mount. Too much the budget option? Not in online store.

Things to learn about:

  • Wedge mounting
  • Astroimaging mounting options
  • Telescope optics: focal length, speed, etc
  • Protocols for mount control
  • Alignment programs, convenience and speed
  • Is it possible (sensible?) to build my own mount?
  • Do I have a clear view of Polaris from the house?

Basic astrophotography

Great article on beginner astrophotography options, on using equipment you may already own to do something interesting. (via Reddit) Some ideas to follow up:

Try using a Barlow to change the focal point on my 8″ Dob, so I can do prime focus images with the old DSLR I have knocking around. Apparently this will work, although the weight and balance may be a problem.

Look into software to manage DSLR focus. The article recommends APT but that’s windows-only (maybe Wine?). Nebulosity looks promising on a Mac. More software options in this old list.

Read the /r/astrophotography FAQ.

GoTo scopes and astrophotography

I’m looking for a telescope upgrade over the basic Orion 8″ Dobsonian I started with. Main things I want are GoTo and the ability to do introductory astrophotography. I’ve been hoping to avoid an equatorial mount because the hassle of setting the scope up precisely seems like an impediment to casual use, particularly since my usual viewing site doesn’t have a clear view of Polaris.

So I asked a knowledgable-seeming guy on Reddit for his advice on whether an alt/az mount with GoTo was sufficient for long exposure astrophotography, and here’s his reply. (Left anonymous).

You can get limited results from a non-equatorial single-fork mount for DSO photography, if the mount supports “wedge” mounting. This aligns the azimuth axis with the earth’s rotational axis and allows for equatorial-like tracking for long exposure photography, without field rotation.

This is a good option if you are doing wide-field imaging (which is also good for beginners). The tracking motors in most single-fork alt-az mounts are simply not accurate enough for high-power long exposures. The NexStar SE mount, for example, doesn’t even use worm gears (the NexStar “Evolution” mount does, however).

The double-fork models from Meade (LX series) and Celestron (CPC series) are wedge-mountable and people are able to get very good results out of them. Wedge-mounting can be an advantageous configuration, especially when dealing with large, heavy telescopes that would require an obscenely expensive equatorial mount to carry properly.

That said, if you’re serious about getting started in DSO photography, you really should invest in a proper equatorial mount.

I guess I shouldn’t be surprised there’s no shortcuts.

Saturn what I saw

The solar system has finally turned enough that it’s convenient to see Saturn at night. So I brought out the scope and got a really beautiful view around 10:30pm. Far enough from the moon that the light wasn’t too distracting, and so bright and full.

I could see the rings quite clearly, including the Cassini Division. No real discernable features on the planet, although it didn’t look uniform either. Titan was quite obvious. A bit of staring and I made out Dione, Rhea, and probably Tethys. They’re pretty close to the planet but clearly separate and all 9-11 magnitude.

Best view was in the fancy Ethos 8mm eyepiece; that wide FOV is really a joy. I swapped in the 7.5mm Plössl and it felt like it was a bit better magnification, but there’s not much point in bothering. And then the 25mm was just disappointing. I sure wish I had even more magnification for bright targets. I couldn’t find my Barlow.

Also got a peak at Mars which was just a red blob, although again not entirely uniform. And some fun views of the moon, I should get a filter and do that for real.

 

M35

I picked out M35 with binoculars last night. Or at least I think I did, I saw a bright fuzzy blob in the right spot. Really not very impressive in the 7x50s, nothing as brilliant or exciting as M44. I guess I shouldn’t be surprised, it’s nowhere near as bright (5.3 vs 3.7) and a third the width. Just sad because a couple of things I read hyped up that this was a really interesting object and a good time to see it. Meh. Maybe better in a telescope.

The good news is I found it by spotting all of Gemini. Constellations, how do they work?