Ep's hard to reach focus.

[Doc]

I have a collection of Baader Hyperion eyepieces, these are the 2" and 1.25" dual fit eyepieces.

When using them in 1.25" style they work perfect. In 2" style most of the time they don't reach focus.

Do I need 2" extender tubes?

But in doing so would this alter the magnification and fov of the ep.

[Doc]

Any idea guys.

I'm considering buying some extentions just want to know if I'm in the area here.

[Milamber]

They will show exactly the same FOV in a 1.25" hole as in a 2", uless you have removed the 1.25" part...

Arthur

[Doc]

They will show exactly the same FOV in a 1.25" hole as in a 2", uless you have removed the 1.25" part...

Arthur

Ahhhh.

So if I remove the chrome 1.25" barrel I will get a wider Fov

[Milamber]

Yes, but you will also introduce more chroma at the edges of the field as a consequence of removing what is effectively a dedicated barlow inside the 1.25" part.

Arthur

[Starflyer]

So if I remove the chrome 1.25" barrel I will get a wider Fov

If you remove the 1.25" barrel you also remove the first group of lens elements and without this group of lenses all of the Hyperion range (except the 21mm & maybe 24mm) will act as a 30mm lens, see page 3 here for more info. Edit: The above should read 'will act as a 22/23mm lens' - I was looking at the field stop column :oops:

It sounds like the lens is going further into the focuser in 2" mode and you need an extension tube to be able to achieve focus, something like this should do the trick.

Cheers,

Ian

[Doc]

Thanks Ian.

Great info on that pdf doc.

Those were the same extenders that I was looking at. I'll order a set.

[Starflyer]

No worries Doc. You'll probably be okay with just the 50mm extension, the Hyperions only go in about another 25/30mm in 2" mode so you need to make sure you're not bringing it too far out with the extension - if that makes sense :?

Ian