Using 2 inch eyepieces in a scope - help please

[Spectre486]

Hi all,

I'm (hopefully) going to be getting a CPC 800 soon, and I'm getting confused about what I need to buy to use 2 inch EP's with it. At first I niavely thought that buying a 2 inch diagonal would sort it out - but now I'm reading about "visual backing plates".

Could anyone tell me what I would need to buy to utilize 2 inch EP's in a CPC 800?

Thx in advance for your help

[Merlin66]

Assuming you want to use the eyepieces with a diagonal, then you need a SCT fitting 2" diagonal. This screws directly onto the rear cell and gives you a 2" output port to hold your 2" eyepieces. You can usually get them with a 2" to 1.25" adaptor so you can still use the standard eyepieces.

( I would question why you want to use 2" eyepieces in the first place.. they and any filters you may buy are expensive and with a C8 don't really add much value - just my 2c)

[Spectre486]

Thx for your reply Merlin

Why 2 inch?

I'm looking to do some DSO viewing at low magnification. The 1.25 inch EP's seem to cut off at around 24mm.

[Merlin66]

Have a look at some of the new wide angle 1.25" eyepieces...I think you may be impressed.

( When I view low power with the C9.25 it's either a 32mm TV plossl or the 40mm TV plossl - haven't tried any of the later UWA type eyepieces...my eyes are not good enough now to appreciate them!)

[Nexus 6]

Hi Spectre486, yes the 2" format is great for observing widefield star clusters etc but I would reakon you only need a couple at most, from there its 1.25 that will do the job either for dso's in the mid to high power range and definately for use when observing the Moon and planets

You can get some decent priced 2" ep's, the Skywatcher Panaview is very highly regarded, I used one myself for a short time.

Hope you do get the scope

[The Bat]

I have a C8 and a Televue 32mm plossl which gives nice low power views.

That said, I also have a 2" diagonal and a 2" 32mm eyepiece (Skywatcher) for it (the only one I have). It does give a nicer frame for larger objects such as some star clusters, Orion Nebula and the Moon - like looking through a porthole. The price for the diagonal + eyepiece was £275.

If you get one specifically for a SCT, you unscrew the visual back from the scope and screw the diagonal in in its place. If you buy a different diagonal then you also have to buy a separate 2" visual back to attach it to.

Rachel