LOL Oh dear James. Well if you can see an image in the viewfinder at least we've eliminated the lens cap being left on.
Welcome aboard mate. What I know about spotting scopes can be written on the back of a stamp. You need to do a bit more than turn the dial to M (Manual) though. In Manual mode you need to set both the shutter speed and the aperture to give proper exposure. Do you get apertures on a spotting scope? I doubt it and if not then you need to experiment by gradually increasing the shutter speed till you get a good exposure.
Pink Fairy is one of the members who comes to mind who knows about spotting scopes and will no doubt see this post and be able to help, although you may need to be a little patient.
I've got a picture of a fuzzy round thing with stripes that my mate John says is Jupiter. Taken using my 20D on his reflector telescope with a T2 adaptor. There is no lens on the camera so no aperture setting is used. It is just a matter of experimenting with the ISO and shutter speed to get the image recorded. My fuzzy circle was 800 ISO and 1/2 second.
If he ever gets his mirror sorted (corroded or something) I'd like to have another go at getting a clear shot.
I'm sure a proper guide will tell you much more but it worked for me
Presumably you're using a 35mm photo adapter in place of the eyepiece... so not digiscoping in the usual sense of the word, but the more established method of turning the scope into a manual focus prime lens.
Sounds as if it could be chronic under exposure. If in manual exposure mode, you'll need to start with a slow shutter speed, check the results and go from there... if the image is too bright, increase shutter speed, too dark and decrease and/or raise ISO setting.
What scope is it? You're likely to be shooting with the equivilant of an f10 at best, or far worse, so there isn't much light getting in.
As you've found out, using a photo adapter to attach an slr camera, you lose most metering functions.. though with a Nikon scope, using their new photo adapter, you do get far more control. Remember aperture control has no effect with a scope, as it's a fixed aperture.
Just as an alternative, if you have a decent scope and a low powered eyepiece, you may want to try using something like the Nikkor 18-55mm lens on the camera and holding this up to the eyepiece on your scope ... you'll get full metering, a bit of zoom to play with and more magnification. Trouble is, it's all a bit awkward to support the camera in this fashion... though handholding the camera is o.k. with fast enough shutter speeds.
A 62mm objective isn't going to help matters... I expect you'll be getting something like 800mm @ f13 or so, if they were clever they'd have made it 600mm @ f10 bt I expect 800mm gets the public a bit more excited.
Another thing I should've mentioned yesterday, normal matrix metering doesn't work with spotting scopes, you'll need to use centre-weighted or spot-metering... which is generally more appropraite for bird photography anyway.
I strongly suspect that you will be unhappy with the results from this scope... even the very best spotting scopes can't perform as well as most genuine lenses. To give you an idea of the gulf between a scope capable of taking reasonable photos in this manner and those at the budget end, just the 35mm photo adapter for a top scope will cost roughly twice what the whole Centon package came to.
Get ready for some serious colour fringing, low contrast images and general lack of clarity. Set camera ISO at the very minimum of 400, 800 is more realistic to get any chance of a sensible shutter speed.
Fair do's, it's probably good value as a spotting scope, but photography is a totally different matter... real-time viewing with your eye and brain (which can cancel out many unpleasant artifacts) is not as demanding as a phyiscal snap shot of the scene that you can analyse at length.
If a basic rough and ready record shot of your subject is the aim (web viewing or small print), it may suffice.