So what would views look like?

[Manok101]

I currently own a 10" and a 4", and I recently saw that Orion has a 14" Goto scope, and was wondering what diffference would going from 14, or to even 20 inches would look like? Or is it overkill to have more than 2 dobs? . I am only curious really. at what point does more stuff become visible?

[swamp thing]

Hi

Some say that somewhere around 16" you leap into another class of observing.

I think the sky you observe through normally has more bearing and limits as to what you will be able to see.

Even a 20" Dob will be limited in severely light polluted areas. Whereas a 10" from an ink black sky is a wonderful tool.

Overkill?: If the 4" is a RFT then no. The 10" will make a great second scope for the times when using a large scope is impractical.

As for the large scope....Go as big as you can possibly manage. You won't be using it every night, but when you do, you want the effort to be rewarded.

If you live at a dark sky sight and can just wheel a big Dob out into your backyard then that's all you're ever gonna need.

Regards Steve

[John]

I've had a quick look at M13 and M51 through a 20" dob last year. The views were really stunning - the objects strongly resembling photographs. M13 was totally resolved and the core appeared to be "crawling" with stars. The full and detailed spiral structure in M51 just jumped out at you - averted vision was just not required.

Massive scope though - it seemed as big as a mini car - totally impractical for me to own even if I had the funds. But, as Steve says, these monster scopes really do take you deep into the universe

[coffee_prince]

this is a question I am interested in. YTo what degree does bad skies limit the usefulness of a telescope? Say a 12 inch scope in the worst rated pollution in city centre vs an 8 inch?

[Manok101]

Would it be worth going after another dob or something else?

[swamp thing]

this is a question I am interested in. YTo what degree does bad skies limit the usefulness of a telescope? Say a 12 inch scope in the worst rated pollution in city centre vs an 8 inch?

A larger aperture will always out perform a smaller one from the same location. So a 12" will show more than an 8" from any location.

That said a 12" that is un- portable and therefore stuck in your LP city back yard will be out performed by an 8" that you've transported to truly dark sky.

Would it be worth going after another dob or something else?

If you have access to dark skies, a large Dob is great, but from LP locations they're a bit strangled TBH.

I seldom bother to use my 16" from anywhere near where I live for this very reason.

I prefer to wait until I can travel to a dark location. Using my baby Dob when other commitments dictate a short session, or the Moon prevents any DS observing.

The wait is always rewarded, it's pretty hard to beat observing with a larger aperture Dob from a dark sky.

Regards Steve

[JimStan]

I have heard the old expression, "The best scope you own, is the one you take out and USE the most!." A 16" Dob would be great, but could you take it some place where you can really get the most return on your investment? A light polluted urban setting is NOT going to give you good views no matter WHAT scope you have. A 16 incher will just show you gray skies, rather than black, if light pollution is any kind of factor at all.

And face it, it is MUCH easier to transport an 8" SCT to a dark location, than it EVER will be to transport that 16" Dob!

My favorite scope is a little ETX-90! I can fit the whole thing, scope, tripod and lens set , under one arm and toss it in the back seat of the car when I want to got to our club's dark(er) sky observing site. ( the fairway of a local golf course !

Welcome at Beaver Creek Country Club

Clear skies! Jim S.

[coffee_prince]

in bad polluted skies, it seems the 8 inch is th best bet then

[banner001]

you also have effects like angular resolution to take into consideration as well, you can view double/triple stars quite fine from LP skies, and what you need there is angular resolution.

LP affects every scope, my 10" is ok, i bet a 12" is probably pretty similar, but a 16" will gather too much LP light, i would say a 12" truss is the cutoff in terms of practicality, weight and views.