Bob's Astrophotography Endeavors: Page 2

Now I am getting serious with this hobby. Now that I purchased my Canon Rebel T31 DSLR Camera, I will need to purchase some adapters to be able to connect the DSLR to the telescope.
I needed a T-ring & 1 1/4" adapter that would insert into the in place of the eyepiece. The T-ring connects to the DSLR camera in place of a lens and the 1 1/4" T-adapter screws into the T-ring. There is no lens on the T-adapter. The light goes directly to the camera's sensor. This is called 'Prime-focus'. The telescope is used as a magnification lens for the camera.

I then tried this configuration on my Celestron 130SLT telescope to see how well it worked. I decided that the first thing that I should try to focus on should be big and bright, so I waited for the next moon phase to come around. On the first night that the moon was at least in half full phase I took my telescope outside to try this new setup. I lined-up the telescope's view finder on the moon and inserted the DSLR in the eyepiece tube. I then turned on the DSLR and saw a fuzzy image of the moon on the camera's 'Live View' LCD monitor. I got excited because it seemed like it was going to work. I then proceeded to adjust the telescope's focuser to get the image in focus. I tried turning the focusing knob in both directions but could not manage to get proper focus on the moon. I attempted again on several nights to obtain the right focus but I could not make it work. After a couple of hours I finally realized that I had the same problem that I had encountered with the flip mirror purchased last year. The DSLR setup could not reach the 'focus point' of the telescope. The telescope's focuser was to tall and so the camera was too far from the focus point to be able to achieve proper focus. I had to find a solution to this problem.

I tried several different configurations and found that one solved my problem. I discovered that by removing the lens off my 2X barlow eyepiece and and attaching it to the T-adapter I could make the focuser reach the proper focus point. The lens's magnification changed the telescope's focus point just enough to so that the camera's sensor can now see clearly.

This is my Orion 2x Barlow with the lens removed and then attached to the T-adapter on the camera

Now that I have figured out how to get the proper focus with my DSLR, I can finally take my telescope out and try out the software that came with the Canon T3i. The software is called "EOS Utility" and is used to control the camera remotely from a computer or laptop. With this software I can see on my laptop screen what the camera is seeing, allowing me to verify that everything is in focus and centered in the frame. With this software I can also adjust the ISO, exposure time, white balance, and program an automatic exposure sequence where I specify how many images to take and how long each exposure should be. So I can set it up to take 50 pictures, each picture having a 15 second exposure time and just sit back and wait for it to do all the work.

After I take all the pictures, I then use a software called 'Deep Sky Stacker (DSS)' to stack all the images over each other to combine the detail from all the pictures into one single image. This process brings out all the fine detail hidden within the pictures. The result is simply amazing.