On Tue, 6 Mar 2007 12:19:58 +0000, Jim wrote:

In article , Pete Lawrence wrote:
On Mon, 5 Mar 2007 08:50:30 +0000, Jim wrote:

I have an older Orion Optics Europa 250 'scope with 1.25" eyepieces. I also have
a Canon EOS350D camera. I'd like to start some simple astro photography, but I'm
completely clueless as to what I need to mate the two together - just how does
the camera get attached to the 'scope?

Any advice gratefully received.

Hi Jim,

An EOS to t-thread adapter to attach onto the front of your camera.
Mine cost me £10 from my local camera shop who had a box of them under
the counter strangely.

Right-o.

You then need a 1.25" nosepiece with a T-thread that screws into the
adapter.

Right-o. I assume that you remove the lens from the camera (told you I was new
at all this) but you are still able to use an e/p with the 'scope?

There are three main ways to couple a camera to a telescope. The first
is basically holding the camera (including it's lens) up to the
eyepiece. That's called afocal coupling. This is normally only done if
you can't remove your camera's lens - which you can. So here you have
an eyepiece and a camera lens.

The second method is eyepiece projection and this doesn't tend to be
used that widely. Here you have an adapter which holds an eyepiece and
allows you to vary the distance between the eyelens (the lens that
would be closest to your eye) and the camera's chip. This is for
cameras which can have their lenses removed (including webcams). So
here you have an eyepiece and no camera lens.

The third method, which is most common with DSLR cameras, is prime
focus coupling. Here you lose both the eyepiece and the camera's lens.
The path to the camera's chip is as pure as it gets - i.e. there's no
glass between it and the telescope's primary mirror. This is the route
you want to follow Jim.

--
Pete
http://www.digitalsky.org.uk