Using a telescope as a DSLR lens
I know that one can use adapters to attach a scope to a DSLR for use as a camera lens. But what are the results? I am interested in both, the quality of the resulting picture and the effort needed to get the picture as compared to a dedicated camera lens. In other words, while it is possible, is it worth the effort?
I have a 90 mm Mak with which I would be attempting to photograph birds, mostly shorebirds and ducks.
The first thing you need to do is decide just what you want in the way pics. Just keeping some 4x6s for a scrapbook is one thing, making huge enlargements and hanging them on the wall is quite another.
Quality can be quite good when using a spotting scope or telescope as a telephoto lens, but, just as with a camera lens, image quality is directly a product of the optical quality of the scope you are using. Don't expect a $200 spotting scope or telescope to rival an expensive spotting scope or telephoto camera lens Not going to happen and not worth the effort if you plan to make something to hang on the wall. If you want wall hanging quality enlargements there are no shortcuts - it will cost you, whether it be a spotting scope or dedicated SLR telephoto camera lens. Of the two, the dedicated telephoto is the best option, but 400mm will be an absolute minimum and getting the aperture you really need is very, very expensive. That's why most folks resort to using a spotting scope. Even a $2000 spotting scope is cheaper than a 600m f4 camera lens, these days. l
Using an SLR with a scope also has limitations and some issues. First of all, spotting scopes or telescopes make very, very slow telephoto lenses. This is especially true of Maks, which are basically in the neighborhood of f/10 to f/13. That means no low light photography - bright day light, only. It also means that ANY movement of the subject means a blurred image and birds are notoriously poor subjects in this regard. In plain English, it means slow lenses take a long time to deliver the needed light and that means long shutter times and long shutter times allow a bird too much time to move.
Focusing is also an issue with an SLR behind a scope. Focusing screens on SLRs are not made for those kinds of focal lengths and those focal lengths also translate to very dark images, which makes the problem even worse.
I would strongly suggest you pursue digiscoping - mounting a small point and shoot digital over the eyepiece. Forget the SLR. Pic quality is not quite as good in digiscoping, but it gives you access to much more magnification and this will get you pics with shorebirds you will never get using an SLR, even with an expensive dedicated telephoto lens of large aperture. It's also much easier in terms of focusing.
I've done both types of bird photography with spotting scopes for years, not to mention many years of using big and expensive telephoto lenses. Most of us are now doing digiscoping. See my blogs for some good examples of what you can do with digiscoping at my blogs, Binoculars and Optics
Try digiscoping, though. If you already have a little point and shoot, just hold it over the eyepiece of your scope by hand and see what happens. If you like the results, go and buy a digiscoping adapter. That's all a digiscoping adapter doers - holds the camera for you.
I probably will as I was thinking of getting one anyway. I already have a refractor spotting scope and am thinking of upgrading to a "near premium" one, the ultra premium Kowa 883 being too expensive for me to justify the cost. I will likely get rid of my Mak as I never did get into star gazing like I though I would.
The Kowa 883 is typical in terms of price for a premium scope, but I have done some greta digiscoping with the smaller and much less expensive Kowa 663. There are also several decent scopes under $1000 that you should consider, including the Brunton Eterna 20-60x80 and the Celestron Regal 80. These will take some great pics, too, for digiscoping.