Hello, I'm no stranger to photography but I'm a complete n00b to astrophotography and astronomy altogether. I have a Canon EOS 400D (Rebel XTi) digital camera and have access to a fairly large telescope with a focal length of 1200mm. I would like to somehow connect my camera to the telescope. I did a bit of research and it seems I need a T-ring or T-adaptor to connect the camera body but I'm still a bit confused. I was going go to my local camera shop but I want to know at least something so they don't try and sell me crap I don't need. Below are pics of the removed eyepeice from the telescope in one peice and peices removed. Someone please tell me exactly what is needed to connect my cam to it.

BTW the reason I want to do this is to take good pics of the upcoming lunar eclipse on Feb. 20th (http://sunearth.gsfc.nasa.gov/eclips...2008Feb21.html) provided there are clear skies. If for whatever reason I can't use my telescope I'll have to settle for my 200mm Canon zoom lens.

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	eyepeice.jpg (34.6 KB, 25 views)
	eyepeices.jpg (40.5 KB, 19 views)

You need a Canon EOS T-ring and a Tele-extender.

The T-ring is a flat metal ring with a bayonet fitting on one side and a screw thread on the other. The bayonet side fits to the 400D where the lens would normally go. One end of the Tele-extender screws into the T-ring and the other end mounts over the visual back of the telescope. You can leave the eyepiece in place for eyepiece projection or remove it for prime focus.

I have a Celestron C8 so my Tele-extender is model #93643.

In my experience the field through a telescope, even at prime focus, is good for only about half of the moon's area. A 200mm lens (equivalent to 320mm on a 400D) will easily fit the moon in. It will also be easier since the camera will autofocus for you, and there'll be fewer problems with vibration and trailing at the lower power.

Here's an uncropped photo of the last lunar eclipse I took with my 400D at around 280mm (tripod not tracked), to give you an idea of the size you'll get.

clop

Attached Images

Lunar Eclipse 280807B.jpg (143.6 KB, 40 views)