Can I upgrade my Celestron 8 SE to take a 2" EP

Got a beginners' question? No matter how elementary, our friendly forum community and magazine writers will answer it.

Can I upgrade my Celestron 8 SE to take a 2" EP

Postby decco15 » Sun Nov 28, 2010 12:16 am

Hi Guys, I would love to upgrade my Celestron eyepieces to include an 8 and 22MM Optima or Axios EP. However, the 22mm will only work with a 2" fitting. Looking at the Celestron site, I note they market a 2" adapter {http://www.opticsplanet.net/celestron-2-inch-xlt-diagonal-sct-93527.html} but I am not certain that this will work on my Celestron 8 SE which has a standard 1 14 fitting. Can anyone advise if this adapter will allow me to use a 2" EP with the SE 8?

Thanks in advance
decco15
 
Posts: 47
Joined: Mon Jul 11, 2011 9:50 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby brianb » Sun Nov 28, 2010 3:36 am

With any Celetron or Meade SCT you can replace the 1.25" visual back with a 2" visual back. There is no point in using an adapter which will allow a 2" eyepiece to be used in a 1.25" diagonal as the field of view will be severely restricted. If you change the visual back to the 2" version you will need to change the diagonal to a 2" version as well, for the same reason.

There are lots of other eyepieces you should be considering. 8mm is a bit short for a SCT, in my experience 9mm is the shortest which actually shows more detail on any subject, and even that is only very rarely when the seeing cooperates. The Meade 26mm series 5000 Super Plossl is an excellent eyepiece in the mid price range and is 1.25" fitting ... there's a 20mm version too if you think that would fill a gap in your power range better. But eyepieces are very personal and you should if at all possible visit a star party and check out what you like before you part with significant amounts of money.

brianb
 
Posts: 5513
Joined: Mon Feb 13, 2012 6:49 pm

RE: Can I upgrade my Celestron 8 SE to take a 2

Postby arthur dent » Sun Nov 28, 2010 1:36 pm

Hi Decco

The p/no for the celestron scopes is #93792 -2 2-inch Visual Back.

The Celestron site says for 11" and 14" SCTs but it works with the 8SE

As Brian says, you'll need a 2" diagonal too. To prevent damage to your eyepieces, choose a diagonal that has a compression fitting. You might also look at a dielectric coated one. Highly regarded are the ones by William Optics.

Art
Last edited by arthur dent on Mon Mar 26, 2012 11:46 am, edited 1 time in total.
Meade ETX-105EC
Celestron NexStar 6SE, 9x50 RACI finder, MRF, powertank & wing thing
Hyperion 8-24mm Zoom + various other EPs
Canon 550D + T-ring, Philips NC880C and 900C webcams for AP (all un-modded)
arthur dent
 
Posts: 277
Joined: Mon Feb 13, 2012 6:52 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby brianb » Sun Nov 28, 2010 2:10 pm

[quote]The p/no for the celestron scopes is #93792 2” Visual Back.

The Celestron site says for 11" and 14" SCTs but it works with the 8SE [/quote]
CAREFUL!!! The 11" and larger scopes have a 3.25" thread onto which is threaded an adapter which converts to "standard" SCT thread ... I think the adapter you mention is the one which fits straight onto the 3.25" threads, which your scope doesn't have. (You get a slightly larger light beam if you can use the "large SCT" threaded adapter.

The one you want is something like [url=http://www.rothervalleyoptics.co.uk/antares-sct-female-2-quot-female-adaptor_d4330.html]this one[/url] (other brands are available, and other outlets stock them ... this may not be the cheapest)

brianb
 
Posts: 5513
Joined: Mon Feb 13, 2012 6:49 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby decco15 » Sun Nov 28, 2010 9:40 pm

Hi Guys, many thanks for the advice, I need to do a bit more research and thinking about my choices. Just to go back to my original question, if I go for the celestron-2-inch-xlt-diagonal-sct-93527 will this work with the 8 SE?
decco15
 
Posts: 47
Joined: Mon Jul 11, 2011 9:50 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby brianb » Sun Nov 28, 2010 9:56 pm

[quote]if I go for the celestron-2-inch-xlt-diagonal-sct-93527 will this work with the 8 SE? [/quote]
That will work with ANY SCT marketed in the last 15 years, irrespective of brand. So will any other diagonal with an "standard SCT thread". There are diagonals which have superior features e.g. compression rings rather than screws which can mark the eyepiece barrel; there are diagonals with better quality optics (at a price) and there are cheaper ones (with dubious optical quality).

brianb
 
Posts: 5513
Joined: Mon Feb 13, 2012 6:49 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby decco15 » Sun Nov 28, 2010 11:03 pm

Perfect, thanks again for your advice Brian
decco15
 
Posts: 47
Joined: Mon Jul 11, 2011 9:50 pm

RE: Can I upgrade my Celestron 8 SE to take a 2" EP

Postby arthur dent » Sun Nov 28, 2010 11:36 pm

Yep,

As Brian has said, this will fit directly to the back of your scope's rear cell. It has an adapter so you can use existimg 1.25" eyepices as well as 2" eyepieces. It looks like it has a compression fitting too, although there is no mention of this in the specs.

Art

Thanks for pointing out my earlier error Brian. I didn't realise that the 11" and 14" SCTs had a larger thread.
Meade ETX-105EC
Celestron NexStar 6SE, 9x50 RACI finder, MRF, powertank & wing thing
Hyperion 8-24mm Zoom + various other EPs
Canon 550D + T-ring, Philips NC880C and 900C webcams for AP (all un-modded)
arthur dent
 
Posts: 277
Joined: Mon Feb 13, 2012 6:52 pm

Re: Can I upgrade my Celestron 8 SE to take a 2

Postby ggreene1 » Sun Mar 25, 2012 3:07 am

I just went through the process of buying a 22mm 2" eyepiece and a 2" dielectric coated diagonal. Unfortunately I made the mistake of not asking questions like you're doing. I didn't order the part to thread directly onto the rear of the tube. http://www.rothervalleyoptics.co.uk/ant ... d4330.html or similar part (visual back I think it's called... I'm new to all this) and now I have to wait for that piece to arrive. Rats... The only thing I can see as a potential problem / challenge is the fact that you could not aim the telescope at the zenith. My 1 1/4" diagonal and eyepiece just barely fit with the scope at the zenith. The 2" set up wouldn't allow this. The way I see it is that I will slew the scope all over the place with the 1 1/4" set up and do some measuring to see where I can go with the 2" stuff installed.
ggreene1
 
Posts: 2
Joined: Sun Mar 25, 2012 2:56 am

Re: Can I upgrade my Celestron 8 SE to take a 2

Postby ggreene1 » Sun Mar 25, 2012 3:30 am

Here is the adapter that I purchased. http://www.astronomics.com/main/product ... t_id/7785C You'll notice that it has the compression fitting that everyone seems to like.
ggreene1
 
Posts: 2
Joined: Sun Mar 25, 2012 2:56 am


Return to Ask a silly (astronomy) question

Who is online

Users browsing this forum: Shannonnet and 0 guests