Canon EOS Rebel xti adaptors

[deckardbr]

Hi everyone,

I was so stunned by the lunar and planetary views last night of my NexStar 6SE on relatively light polluted skies (I honestly did not expect it to perform SO well)... which I now feel the need to try and take images of them. For DSO photography I intend to use a separate solution... so not a concern here.

I have a NexStar 6SE SCT with a 1 1-4" visual back and also a 2" adapter for wider field views.

Camera: I have a Canon EOS Rebel XTI.

What's the "best" solution to attach it to the back of my SCT? What do I need to buy? I researched the forums but only found a mixed of options of which I'm not sure which works "best".

I read that you typically need 2 pieces. One that attaches to the camera and one that links it to the back of the SCT.

1) Is there a 2" and a 1 1/4" setup option? WIth Lunar, I see I could benefit from a larger FOV.

2) Dumb question. If I need eyepieces/barlows to achieve the 200x magnification... is the camera supposed to be attached... at the end of the "chain"? I can't even imagine how that would work! It would be very heavy and attached to a 20cm long chain of lenses! :huh: .

Any advice/help greatly appreciated...

Andrea

[Tinker1947]

I would think one of these.....plus the Canon T-Ring....

http://www.firstlightoptics.com/adaptors/celestron-sct-t-adapter.html

[deckardbr]

Thanks - I was checking the forums further and realized there are 2 main types of photography. Prime focus or eyepiece projection.

My questions now change to the following:

1. In Prime Focus (with sct adapter + t ring)... how do I calculate the magnification that I get? NexStar 6SE has 1500mm focal length and 150mm aperture. Do I need to know the CCD chip size? Is there a way to "zoom in" in prime focus with a barlow?

2. If I want to "zoom in" on objects such as jupiter or saturn, is "eyepiece projection" the only option? Is this needed even with the barlow?

Thanks!

Andrea

[scoobee]

I have the nexstar 4se and just started in astrophotography.

I did use the prime focus but prefer using the eyepiece.

The problem with prime focus is that you are limited to what you can do as far as I can see.

My main tools are the orion steadypic mount,baader hyperion mainly 10mm) with a Baader Hyperion eyepiece T-Adaptor and my DSLR. Thus, I use the eyepieces for magnification.

I am new to this so you might be worth checking with others but I seem to have cracked my system.

[Cornelius Varley]

There is no "magnification" with prime focus photography, consider your telescope as a 1500mm fl telephoto lens. You can use the FOV calculator http://www.12dstring.me.uk/fov.htm to work out the best focal length to use for your telescope. I tend to use a 2x barlow to give me the ideal arcsecond/pixel ratio, your 6" SCT will be the same also. For eyepiece projection I put together a spreadsheet to calculate magnifications.

eyepiece projection rev2.xls

[NGEddie]

Just want to add my thanks, that fov website is very helpful.

Sent from my iPad using Tapatalk HD

[deckardbr]

Scoobe: thanks. Is this an afocal setup or eyepiece projection? Sorry still learning basic terminology. You are 'linked' to the eyepiece not just in front of it?

Cornelius: very useful stuff, thanks! Can I ask you about your 'full setup' for AP? Specifically for planetary.

Thanks again to both

[scoobee]

Deckardbr, as for Afocal and Eyepiece projection not sure but I have all ways thought of it being Afocal rather then Eyepiece Projection, if anything I think Eyepiece Projection is related to SCT's and Afocal is related to refractors, but still not sure.

As for the eyepiece linking to my DSLR, this is done via an adaptor screwed on the top of the eyepiece and then connected to the DSLR, I presume but not sure this will allow the use of Barlows to increase the magnification subject to seeing conditions.

Hope I am helping and not confusing the problem?!

[deckardbr]

I think it makes sense

How is the eyepiece coping with the weight of the dslr? Is it a 2" EP? Do you use any other type of support?

Thanks!

[scoobee]

I use the Orion SteadyPix Delux Camera Mount, link below.

It does the job, you connect the camera mount to the eyepiece holder on your scope, put the eyepiece in the holder then connect your DSLR which is supported by the camera mount.

I have seen others being used and the Orion seems to be loved by those who have seen it.

http://www.scsastro.co.uk/catalogue/orion-steadypix-deluxe-camera-mount.htm