There wouldn't be much benefit in purchasing a 2" diagonal if you don't have
any 2" eyepieces. A couple of things to consider are that 2" diagonals are
generally higher optical quality than 1.25" models and that almost all 2"
diagonals have a compression ring that holds the eyepieces better than just
Regarding dew straps, the eye lens is rather large so if you have a
significant dew problem in your area you will need one. The diameter of the
eyepiece is a bit less than 60mm.
Author of "The NexStar User's Guide"
Author of "NexStar Observer List"
] On Behalf Of rlderderian
Sent: Wednesday, April 09, 2008 9:14 AM
Subject: [Baader-Planetarium] Re: 24mm
Thanks for that answer. Now with that in mind, if I never buy a 2"
EP, is there any reason to get a 2" diagonal?
--- In Baader-Planetarium@yahoogroups.com
, "Mike Swanson"
> The view is exactly the same whether you are using the eyepieces in
> 1.25" diagonal or a 2" diagonal. Regarding using them in a 2"
> diagonal, the lowest black section of the eyepiece is the 2" barrel
> so you slide the eyepiece in as is. For a picture of how that
> see the Files section of this Group and view the various manuals
> brochures posted there. Note the description urging care when
> these eyepieces in a low profile 2" diagonal - it is possible for
> 1.25" barrel of the eyepiece to bang into the mirror in some
> If you find this to be an issue with a given 2" diagonal, Baader
> created 2" stop rings to prevent this problem.
> One additional note - the 13mm has the option of removing the 1.25"
> barrel from the bottom of the eyepiece which takes the first lens
> group with it. In that instance, the eyepiece can only be used in
> 2" diagonal and the focal length changes to about 23mm. In this
> configuration, the view at the edge of the field deteriorates and
> since you already have the 24mm, you probably won't want to use the
> 13mm in this fashion.
> Best regards,
> Mike Swanson
> Author of "The NexStar User's Guide"
> Author of "NexStar Observer List"
> --- In Baader-Planetarium@yahoogroups.com, "rlderderian"
> <rlderderian@> wrote:
> > I have a CPC 1100. I just received the 13mm and 24mm Hyperions.
> > the future I am going to get a 2 diagonal. How do you convert
> > EP's to 2"? Do you need additional parts? Will these EP's give
> > views with a 1.25" diagonal or 2", or about the smae?
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