C11 2" Visual Back?

[ixalon]

Hi all,

This is probably a better place to ask this than my welcome post.

I'm getting hold of a 2nd-hand C11 this week (can't wait) and a friend has offered to loan me some of his equipment to try out - however it's all 2". For the life of me I can't find a 2" visual back for the C11 in the UK.

From various posts it seems the best bit of kit is the Astro-Physics Inc. ADASCTLC Astro-Physics Focusers, Adapters and Extensions but is there anywhere I can get this from in the UK, or will it have to be an import?

Hoping someone can help,

Chris

[Space Bat]

Have you tried asking any Celestron Dealer??

David Hinds is the UK importer so - if you place an order through any Celestron dealer - they will get David Hinds to ship one in - possibly speak with David Hinds to see if they have any left over from when they used to retail, or they maybe able to point to dealers that have recently received one.

Chris

[brianb]

This site's sponsor lists the William Optics 2" visual back at £34 ...

[ixalon]

Thanks Chris and Brian.

I'd searched on First Light Optics for "visual back" and came up blank. I should have browsed more carefully!

Thanks again,

Chris

[chuenmanc]

Hi

The benefit of the AP visual back is that it uses the larger 3.25" threads on the back of the C11, giving a full unrestricted light path. Other SCT visual backs (including the WO) are limited to the smaller SCT threads. Another (very expensive!) option is to go for a Feathertouch or Moonlite focuser, as these can come with adapters for the large threads.

[ixalon]

Thanks chuenmancm. I contacted AP and got a quote for delivery to the UK (a very reasonable $13!) Now just to see how much the post office decide to ask for VAT, duty and "handling fees".

[chuenmanc]

Good choice

[brianb]

The benefit of the AP visual back is that it uses the larger 3.25" threads on the back of the C11, giving a full unrestricted light path. Other SCT visual backs (including the WO) are limited to the smaller SCT threads.

This is perfectly true, but the issue is moot unless you're using eyepieces that really push the limits of the 2" drawtube - or imaging with a full frame camera.

2" visual back on SCT threads vs 1.25" visual back on SCT threads: huge increase in unobstructed field width. 2" visual back on 3.25" (large SCT) threads vs. 2" on normal SCT threads: small increase (of the order of 10%).

BTW I do have a 2" / large SCT adapter on my C11 - the Celestron one - got it through Hinds last year without any particular problem. The AP version may be nicer if it has a compression fitting to hold the eyepiece / diagonal instead of the metal thumbscrew bearing directly onto the accessory as with the Celestron. The optical performance is unlikely to be any different!