Canon 6D and Moonlite

[AScheps]

Hi there,

I have two questions related to using a Canon 6D and Moonlite focuser on an 8" SCT for imaging.  I will be using the taller flange for the Moonlite focuser so I can put the focal reducer inside the focuser.

It seems to me that I should get a Canon bayonet to eyepiece adapter and avoid a T-thread altogether.  This would get the camera as close as possible to the focal reducer and also keep the length of the gear attached to the tube from becoming ridiculously long.  Am I missing something here?  Is there an advantage to having a T-thread adapter in-between?

Second question is about whether to use an adapter to 1.25" or 2".  To save on having to buy 2" filters I was thinking that 1.25" would be the way to go, but with the 6D being a full frame camera am I giving up a lot using a 1.25" adapter instead of a 2"?

Thanks a lot,

Andrew

[Owmuchonomy]

I don't have first hand experience of the specific kit you mention but what I can report is that my 9.25" SCT with a 600D crop sensor suffered vignetting particularly with a reducer.  Therefore I would guess that you won't get anywhere close to being able to use a full frame sensor?

[michael8554]

Putting the reducer inside the focuser is a good idea as it reduces the length of the imaging train, but perhaps I've misunderstood what you have said, it is unusual for a camera to be mounted "as close as possible to the focal reducer", most reducers have to be mounted at a  specific spacing..

Michael

[AScheps]

 

9 hours ago, Owmuchonomy said:

I don't have first hand experience of the specific kit you mention but what I can report is that my 9.25" SCT with a 600D crop sensor suffered vignetting particularly with a reducer.  Therefore I would guess that you won't get anywhere close to being able to use a full frame sensor?

This is part of why I want to try a true 2" adapter.  The Celestron T-Adapter has a barrel that's much smaller than 2" and then it opens back up.  I'm hoping that a true 2" barrel will be much better for vignetting.

51 minutes ago, michael8554 said:

Putting the reducer inside the focuser is a good idea as it reduces the length of the imaging train, but perhaps I've misunderstood what you have said, it is unusual for a camera to be mounted "as close as possible to the focal reducer", most reducers have to be mounted at a  specific spacing..

Michael

Sorry, I'm still figuring all this out and looking back at my post I can see I didn't explain myself very well.  According to everything I can find out the optimal distance between the focal reducer and the sensor would be 110mm.  Forgetting about the Moonlite for a second, if I mount the focal reducer directly on the telescope and then use the standard Celestron Cannon T-adapter it seems to be around 100mm and I've had good results this way.  The whole point of the post though is that I feel like I should be taking advantage of the Moonlite when using the DSLR.  So, this brought me to the idea of putting the focal reducer inside the Moonlite and then getting the DSLR directly on the focuser.   The reason is because there is about 70mm of distance just within the focuser so if I added the Celestron T adapter I would be way over 110mm.

One strange aspect of this setup is that focusing will actually change the distance as it racks the camera in and out so I guess another question is how critical is this distance really?

 

 

[AScheps]

I've just found out the reducer is attached to the draw tube so the distance doesn't change, which makes a lot more sense!

[Ken82]

Changing the adapters wouldn't change the vignetting trust me I've tried with an 11"edgehd and canon 6d . You can of course crop your photo afterwards but I'm not sure how much would be usable . Remember the edgehd was specifically designed for larger sensors but celestrons claims are wide off the mark . 

[Owmuchonomy]

10 hours ago, AScheps said:

 

This is part of why I want to try a true 2" adapter.  The Celestron T-Adapter has a barrel that's much smaller than 2" and then it opens back up.  I'm hoping that a true 2" barrel will be much better for vignetting.

Sorry, I'm still figuring all this out and looking back at my post I can see I didn't explain myself very well.  According to everything I can find out the optimal distance between the focal reducer and the sensor would be 110mm.  Forgetting about the Moonlite for a second, if I mount the focal reducer directly on the telescope and then use the standard Celestron Cannon T-adapter it seems to be around 100mm and I've had good results this way.  The whole point of the post though is that I feel like I should be taking advantage of the Moonlite when using the DSLR.  So, this brought me to the idea of putting the focal reducer inside the Moonlite and then getting the DSLR directly on the focuser.   The reason is because there is about 70mm of distance just within the focuser so if I added the Celestron T adapter I would be way over 110mm.

One strange aspect of this setup is that focusing will actually change the distance as it racks the camera in and out so I guess another question is how critical is this distance really?

 

 

I use a direct SCT connection which is 2". You will get serious vignetting.