Bird photo experiment
I wanted to take a picture of a red bellied woodpecker we saw a few days ago but the distance and not having a camera ready made it impossible. We have a spotting scope set up on a tripod in the house for bird watching so I put a digital camera (handheld) up to the eyepiece of the scope to see if I could get a photo of birds using that method. I was mildly surprised that the camera could actually focus and take a photo through the scope. I found that extending the camera's telephoto lens to about 50% of it's maximum gave the best results as in the photo of the junco. The downy woodpecker was taken with the lens fully extended and gave a blurry picture, the camera seemingly unable to focus as the out of focus warning lights came on. I took the photo despite the warning because I was afraid the bird would fly away.
The spotting scope has a zoom from 20x to 60x but I used it in the lowest setting as the light was severely diminished in any other setting. The camera's telephoto is 6x with the best results at 3x. I don't know what the final magnification actually is, whether 23x (20+3) or 60x (20x3) but the birds were shot at a distance of about 50 feet so the magnification is quite significant.
The subjects have to be carefully centered using the lcd because the size of the scope's objective lens limits the coverage. You can see how it cuts off the photo especially in the junco picture even with a 80mm objective lens.
Far from best for bird photography but fairly fast to set up and able to get some kind of a picture at long distance. A desperate measure at best. The good part is being in the warm house rather then stealthily trying to get close enough with your regular telephoto when it's cold and miserable outdoors .