2" Eye Pieces

[steve591]

So if I'm going to get some better eyepieces, just how much better would 2" be for me over 1.25" on a celestron nexstar8?

[John]

Hi,

A 2" eyepiece is not actually better quality than a 1.25" one. The advantage with the 2" size is that a wide field of view can be shown and thats it really.

Folks who would like a really wide field / low power eyepiece usually have one 2" eyepiece for that purpose and the rest in the 1.25" size and use an adapter when they use those.

With the Nexstar 8 you would also need to get a 2" diagonal if you don't already have one. This could accommodate the 1.25" eyepieces by using the adapter mentioned above.

[bomberbaz]

Further to John's reply above the next question is, How much do I want to spend?

You can get a 2" plossl type EP that would work fine in your scope for around £40 or pay £600-ish for a top of the range piece of glass.

They both do the same job, just the more expensive one will do it a little better and retain its resale value better.

Steve

[Ruud]

Hi Steve,

by a lucky coincidence we recently discussed the virtues of 2" eyepieces in the thread Advantage of 2" eyepiece. The thread has 28 posts and is probably worth your while to read.

One thing we may not have discussed there is that an 8" SCT has a baffle tube of 37 mm or so. This means that the widest view, longest focal length eyepieces may vignette a bit on those scopes. A 40mm 68° eyepiece is an example. 

The vignetting you get is not abrupt, though. It's a slow drop off of illumination toward the edge of the field.

Clear skies!