6 replies to this topic

[rumbers]

Hi, quick technical question if I may...

 

I am about to take delivery of a second hand Celestron Nexstar 6SE (very exciting), which I'd like to link up to my Canon 5D MkIII to try my hand at a bit of astrophotography.  

 

I've found what looks like the correct T-ring adapter (Celestron 93419 T-Ring Adapter for Canon EOS Digital Cameras), but do I also need a T-mount adapter (if so which one)?  I also saw somebody's post on this forum which mentioned adding a 'Visual Back' into the mix, but what on earth does this do, why would I need one, and which one would I need??  Sorry - I'm just desperately trying not to buy the wrong bits. Sigh. 

 

Sorry for the probably very basic question - just a bit lost.

 

Thanks,

 

Mat

 

 

[Maritime]

Welcome. That is a fine scope but I can only help a little: a visual back screws onto the rear of the tube so that other equipment, such as a diagonal, can be fitted. Your scope, if complete, comes with a visual back. 
 

Did your seller describe only the optical tube, or provide a complete inventory?

Edited by Maritime, 20 January 2021 - 01:30 PM.

[UT_JimW]

There are T adapters that screw onto the SCT threads at the back of the scope.  The T ring for your Canon brand camera then attaches to the adapter.

 

T mount adapter

 

https://www.bhphotov...OR_Digital.html

 

There are ultrawide adapters that might work better with the full-frame Canon 5D.  Interestingly, they may not be available from the original supplier, but they also turn up used.  These can fit into a focuser or the usual visual back.  Note that they recommend a clear filter on theirs (threaded for a filter) to protect the camera sensor.

 

Ultrawide adapters - 

 

https://www.telescopeadapters.com/

 

https://www.telescop...IAGRAM_700W.jpg

[bobzeq25]

You want a piece that looks like this.  Plugs in like an eyepece, has t-threads that thread into the Celestron camera adapter.  I paid no attention to the vendor, just wanted to show you what it looks like.  Amazon has full kits.

 

http://www.opticstar...=0_10_5_0_3_720

 

You may need spacers, most imagers have a drawer full.

 

https://www.amazon.c.../dp/B071ZSB7HC/

 

Heads up, since this is a DSO forum.  That scope is difficult to break into imaging DSOs with, for a variety of reasons.  Many try (because it IS a good visual scope, which is unfortunately not relevant, contrary to your intuition).  The general rule (with very rare exceptions) is that they find it frustrating and not much fun.

 

The general solution is to keep it for visual only, and get a good mount (the most important part of a DSO imaging setup) and small refractor to start learning the complicated art of DSO imaging.  Just one example (I have many), but a _really_ common experience.

 

"I regret spending the first 6 months trying to learn <DSO> imaging with an 8" Edge, with that scope it was a losing effort. Fortunately got a nice little refractor, and not only have the quality of my images improved but I'm actually enjoying the process of learning how to do it!"

 

The inexpensive workaround is a camera and a lens on a camera tracker.  You can do excellent DSO images with that setup.  In contrast, the big scope just messes things up.  Did I mention this was not intuitive?  <smile>

 

Planetary/lunar is completely different, because they are extremely bright compared to even so-called "bright" DSOs.  But, for DSOs, this is not _remotely_ a simple matter of connecting a camera to a visual scope.

Edited by bobzeq25, 20 January 2021 - 02:13 PM.

[barbarosa]

This part, a Celestron T adapter threads onto the rear port. The T ring for the camera threads onto it. 

 

The visual back is the adapter held to the rear port of the scope with a threaded ring. It is there to accept slip fit 1.25" accessories, such as a diagonal or an eyepiece, or a 1.25" camera nosepiece. I t looks like this-

 

 

 

 

So you can set up this way, camera w/T ring> Celestron T adapter> rear port of scope. However depending upon the physical size of the camera it may not clear the base as you elevate the scope toward the zenith. 

 

In that case you would use the star diagonal that comes with the scope and a 1.25" nosepiece on the camera (not the T adapter mentioned earlier). The train would be camera > T ring> 1.25" nosepiece> star diagonal> visual back> rear port.

 

If you want to try imaging with a Nexstar SE, as I did, start with a visit to the EAA forum. EAA, live or real time imaging uses shorter exposures and free software to capture, align, stack and display and it works on an alt az mount. The SE mounts are going to be frustrating for more traditional long exposure astro imaging. 

 

I do not know how well suited  your camera is to any flavor of astro imaging, but why not give it try? You may also find that your cell phone's camera works when attached to an eyepiece. There are adapters to hold the phone steady. 

 

Good advice to get used to your gear first as a purely visual setup, then give EAA a try

[peta62]

I am afraid you will have hard time with vignetting on full frame. I know I have Canon 5DIII myself. You have to buy M48 thread on the T-ring, not only M42 and get 2" gear where available for your scope, nothing 1.25" if possible. Any 1.25" brings terrible vignetting. I have C9.25, I am not sure about 6SE, but I have 2" equipment, T-ring with M48 screwed on 2" visual back on Mak 127, so it should work for your scope too.

[rumbers]

Everyone, thank you SO much for the advice. What a great forum. No moans about noob questions, just good honest (and detailed) help. Thanks all