I don't want to dampen your enthusiam for digiscoping, but the DSC-F717 is really not amenable for terestrial digiscoping. The very qualities which make you camera such a great digital tool, prevent if from doing well with this type photography.
To digiscope, the camera must actually shoot through an eyepiece on the telescope. Specialized eyepieces are made which will connect larger lens cameras such as yours to a telescope, but even the largest of these such as the ScopeTronix Max 40 will not prevent vignetting (black areas surrounding the image) especially in the corners. The camera must be zoomed into full 2x digital zoom to get even a useable terrestrial center to crop.
It will work for astro-photography (moon, stars, planets., etc.) because the vignetting is lost to the blackness of space. But when digiscoping for birds, etc., you really need some room to frame.
Very small lens cameras such as the Nikon CP4500 work very well for this type photography. With the proper eyepiece, they allow a great deal of vignette free zoom. Rather than spend your money for peripherals and not be satisfied with the results, it would be better to save and buy one of the CP series Nikons to do this with. The CP950, 990, 995, 4500, etc., all work very well.
Here are two images using the Nikon CP990. The first (starling) was taken at a focal length of 5989mm and the second (robin) at about 2300mm.