Getting black images w/Canon & Celestron SCT

So I'm new to astrophotography. I have a Celestron SCT 9.25" scope, and a Canon 7D (and/or 50D). I have the Canon T-adapter and T-Ring which fits good and snug, and looks much like this picture: http://www.88qv.com/ne​t/lens.jpg (note: not my pic, just one I found posted here). I also have the Canon camera (either 50D or 7D) hooked up via USB cable to my laptop and using the EOS Utility to capture images without touching the camera.

The major problem: I am only getting black images, regardless of how or what I take pictures of. At times I did get a sort of white halo (which looked a lot like taking the Star Diagonal off the scope and looking directly into the tube at a bright object). Regardless, I am at a loss for why I'm getting zero results. Right now is a perfect night and I'm out in the middle of nowhere, perfect for taking images, but I can't take any since it's not producing anything but blackness. I have also tried using the Live View feature of the EOS Utility which also produces an all-black view. I have further troubleshot this by pointing it directly on Saturn (and anticipating it being in center view while I adjust it for the camera), and still getting all black images. I have also tried using the Barlow 2x magnifier lens between the scope and the camera using one of the T-adapters (I have 2) - same thing. Any help on this would be EXTREMELY appreciated. Also, I have both a Celestron T-Adapter (93633-A - http://www.amazon.com …-Telescopes/dp/B00009X3​V8) for Canon, as well as the Celestron T-Adapter 93625 (http://www.amazon.com/​camera-photo/dp/B0000665V6), and the Canon T-Ring which works for both adapters. Both hook up in different ways to the telescope, but both produce the black images. Unfortunately in the past few nights I have been testing the adapters, the moon hasn't been out (easiest target to test on, I would assume).

EDIT: And it doesn't appear to be anything blatantly obvious, such as having the scope's lens cover on (since I am able to view through the regular scope lens without camera just fine).

Again, any help would be greatly appreciated - I've spent way too much money on this equipment just to not be able to use it correctly.

Thanks!

My guess is that you are way out of focus for the camera and you are seeing the central part of the out-of-focus star. The middle of the donut.
The focus point for the camera is a long way from the focus point for an eyepiece. The difference is about 2". With a simple eyepiece like a Plossl, the focus point is about at the shoulder of the eyepiece and for the camera, it's at the sensor plane which is marked on the body by a circle with a line through it.
A simple way to get in the ballpark is to focus with an eyepiece in a 2" diagonal and then remove the diagonal and put the camera on in it's place. The diagonal approximates the difference between the two focal planes. You should then be able to see donuts and adjust the focus to make them into dots.

SteveInNZ wrote in post #16085123
My guess is that you are way out of focus for the camera and you are seeing the central part of the out-of-focus star. The middle of the donut.
The focus point for the camera is a long way from the focus point for an eyepiece. The difference is about 2". With a simple eyepiece like a Plossl, the focus point is about at the shoulder of the eyepiece and for the camera, it's at the sensor plane which is marked on the body by a circle with a line through it.
A simple way to get in the ballpark is to focus with an eyepiece in a 2" diagonal and then remove the diagonal and put the camera on in it's place. The diagonal approximates the difference between the two focal planes. You should then be able to see donuts and adjust the focus to make them into dots.

That is what I was thinking after some brainstorming today. I will try focusing with the scope the next time I break it out - probably in the next few days.

Thanks for your input!

Ok, so after more fooling around, I have figured out a bit more. I took more pictures tonight and the closest I got to Saturn being in view was this:

http://i.imgur.com/03R​NK3a.jpg

I believe what *MAY BE* happening is tthere may be something inside the telescope tube throwing off the focus of the camera (dust specs maybe?). I don't believe it's on the camera mirror since neither camera I've used has any problems focusing while taking normal pictures. I will see if I can clean out the tube tomorrow to hopefully eradicate the issue in time for tomorrow night.

Also, it's not a focus issue since I was adjusting the focus on the telescope consistently while taking these pictures and there was no change. I know this *should* be Saturn since I took a steady stream of shots and the halo object moved in a diagonal position each time. If you have any other suggestions, by all means let me know.

That's exactly what an out of focus star or planet looks like. If winding the focus knob isn't changing the size of the donut, you may have reached the end of the focus travel. That could either mean that you need to add more space (extension tube) between your camera and the telescope or you have wound the focus in the wrong direction.
It might be easier to test it out during the day on something a long way (ie. miles) away.

You should have enough focus travel on an SCT. Try focus to (near) infinity in daytime. You may see nothing on the LCD at nighttime even doing this, but a 10 sec exposure at ISO 3200 should show some blobs. Use a high ISO so you don't have to take long exposures, because you need to make tiny adjustments to the focus until the stars are focused enough for focusing by live view.

Another issue is that he field of view of a 9.25 SCT is pretty small - it is hard to point it at a bright target for focusing because of this.

What are you trying to photograph?

This happend to me with my canon and my celestron edge. I actually had to wait till the moon was up to focus the scope correctly. Now I have no problems. I was so far out of focus it was horrible.