DLSR & Celestron C8N

[bodtwo2]

Hi all,

I have a Advanced VX mount with the C8N Newtonian OTA. Could someone point me to what I need to mount a 450D to the focusser on this please?

 

I have replaced the stock focusser with a moonlit crayford (50mm) and have already purchased a t adaptor and the celestron t camera adaptor with Barlow lens.

 

thanks for the help all.

[alacant]

Hi. Guessing you're missing this. If not, could you post a picture of why it's not fitting ATM? Or do you mean you can't reach focus with what you have? HTH

 

[bodtwo2]

I have one of these T Adaptors which has a barlow i can either use or not, connected to a CR1 50mm Focusser using the 8inch installation kit. So i can create an image train but cannot get it to focus. All i get are images of the secondary mirror and spider.

[ollypenrice]

I wouldn't use the Barlow. It will slow you down, increase focal length (and so complicate guiding) and take you to an unrealsitic pixel scale.

I guess the camera is too far out to come to focus, rather than too far in? Of the three blackened componets to attach the Moonlite to the tube in the lower picture, is the middle one necessary? It may just be a spacer to take everying out from the tube. If so, try without it. (I don't know the details of this system first hand.) Also, in the top picture, you have a 1.25 adapter in the drawtube. If you took that out and used a 2 inch nosepiece as suggested by Alacant you'd come a bit closer.

After that you have to attack the problem from the mirror end by moving the primary up the tube to push the light cone further out. If you only need a bit of a movement up the tube you might find you can get it from simply the collimation screws. Otherwise you have to drill a new set of holes in the tube and move the mirror cell upwards.

I wonder if the Moonlite you have has a sufficiently low profile for this scope? I don't know.

Olly

 

[PatC]

I also have the c8-n  / AVX combo. For prime focus imaging, you of course need a t-ring, but you do NOT use a t-adapter with the stock focuser. A t-adapter will not allow you to rack in enough to achieve focus. The only time you would need a t-adapter is if you plan on using a Barlow.

Completely remove the eyepiece adapter from the focuser by loosening the 2 large thumb screws. Then, unscrew the 1.25" holder that is threaded into the 2". Your t-ring will thread directly onto the 2" eyepiece holder. Replace the joined 2"/t-ring assembly on the focuser with the thumb screws. Now, mount your camera on the bayonet fitting.