Nextar 8 SE

[Lance Bridwell]

What is the focal length of a Nextar 8 SE?

[Dave In Vermont]

You'll find the answer(s) contained in the body of this:

CELESTRON_NexStarEVOLUTION_Manual.pdf

Welcome to SGL - we love questions!

Dave

[Glimpse111]

3 hours ago, Lance Bridwell said:

What is the focal length of a Nextar 8 SE?

2032mm and it's F10.

Regards

AJ

[cloudsweeper]

Yes, 2032mm.  But being a catadioptric, the actual tube itself is only 420mm - a very manageable size.

And a great 'scope!

Doug.

[laudropb]

It's a very nice scope for planetary and lunar observation. Not so good for DSOs

[Cosmic Geoff]

23 hours ago, laudropb said:

It's a very nice scope for planetary and lunar observation. Not so good for DSOs

That's the received wisdom. In fact this looks like a classic example of observer bias. A fairly small number of deep space objects well known and loved by amateur observers will not fit into the low-power field of a SCT. But about 90% of the Messier objects will.  The Local Cluster galaxies including M31, M33 won't. But millions of more distant galaxies will (if you can see them).

The lowest magnification of the 8SE as supplied is 81x with a 25mm 1.25" eyepiece.  Some SCTs fitted with 2" focusers should go lower. Having used a 8" f5 Newtonian on a small sample of deep space objects I can say that some looked best at x40 and some at X100. You can't buy one scope that does everything.

[cloudsweeper]

I get x48 at about 1.34 degrees out of mine - and that's at a good exit pupil which provides contrast.  (42mm 2" EP.)

As for M31, most of us can only see the core anyway!

Doug.

[laudropb]

I had the use of an 8SE for a month a couple of years ago. The lowest power eyepiece I had was a Maxvison 24 mm. I found the contrast on many DSOs to be quite poor, if I could see them. I decided not to purchase the scope as I was getting nicer views with my 8 inch DOB. I do not think this reflects bias, but an honest opinion of the scope in my hands.