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Connecting a Canon xsi to a telescope

Allie Overton , Dec 05, 2008; 04:29 p.m.

I just bought a Canon Xsi. My grandfather gave me his Telescope. It is The Discoverer Bausch and Lomb 60mm Telescope. He gave me his adapter. It's called a Telephoto adapter and screws into the eyepiece. On the base it says Bushnell # 20-0008. The only problem is that it is too small for my camera because it is made for a 35mm camera. I have been looking on the net and I think I just need a T-ring. Is this correct? Or do I need a new adapter to?


Jeff Lear , Dec 05, 2008; 05:26 p.m.

Typically, in order to adapt an SLR or dSLR camera to a telescope (or spotting scope) you require a "T" adapter which will thread onto the visual back of the scope, then you need a threaded bayonet ring specific to your camera that will thread mount to the back of the "T" ring.

I did some research and it looks like Bushnell/Bausch and Lomb does not make a camera body adapter for the Canon EF lenses (although they do for the old Canon FD lenses). However, the threaded back of the T ring appears to be a standard thread that will fit camera body adapters from Celestron and Meade. I would confirm this before you plunk down your $15.00.

Good luck.

Here are some links that might help you out:


Allie Overton , Dec 05, 2008; 08:37 p.m.

The problem is I looked online and it seems that the T-ring is threaded on the side that attaches to the telescope. The T-adapter that my grandfather gave me connected directly to a 35mm camera. It threads on to the front of the telescope and then clicks in directly into the 35mm camera. Is this how most of them are? I don't know how to explain it but it has the threading that goes where your lens goes. It doesn't need another adapter to go into the 35mm. The only problem is that it is too small to go onto my camera. Does a T-ring just make the threading on the T-adapter fit a bigger camera? Or do I need a different adapter? Thanks

Mark Nagel , Dec 05, 2008; 08:53 p.m.

First you need to determine if your diagonal is 2" or 1.25"  then one of these will work.  Ised the 2" on my 10" Meade LX200GPS.

These hook to the camera and the diagonal where the eyepiece would go.




Tommy Lee , Dec 05, 2008; 11:05 p.m.

The Discoverer Bausch and Lomb 60mm Telescope require two adapters to connect to a DSLR. The first one convert it to t-mount, B&L part number is 22-3030, Telephoto Camera Adapter. It is about $25. There is currently one at ebay. You can look at picture of it if you seach for item number 150313824573. This adapter convert the scope to a slow 1000-4000mm T-mount telephoto lens. You can then buy a standard EOS T-mount adapter to connect it to your Canon (about $15).

Jeff Lear , Dec 06, 2008; 12:11 a.m.

Because the scope you are referencing is called both a telescope and a spotting scope (depending on where you look), it may not have a star diagonal as Mark has suggested.  The star diagonal is a prism box that changes the orientation of the eyepiece from horizontal (straight out the back of the scope) to vertical (you look down, into the eyepiece).

It threads on to the front of the telescope and then clicks in directly into the 35mm camera.

I assume you mean it threads to the back of the telescope?
It is possible that the T-ring adapter and camera body adapter are threaded together.  Have you tried removing the camera adapter from the tube that makes up the T-ring assembly by unscrewing it?  Maybe what you should do is use that fancy new Canon Xsi to take a picture of what you have so we can all see!
In most cases (but not necessarily yours), you would remove the diagonal, which threads to the back of the scope, and replace it with the T-ring and camera body adapter.

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