Taking photos through a telescope eyepiece is an ideal method for nature and planetary/solar photography. Your astro targets can include the moon/lunar eclipses, sun/solar eclipses (with solar filter on telescope!), bright conjunctions,and even planets. Recently, people have been stacking images through the eyepiece for deep sky imaging.
Tele Vue adapters allow solid, accurate attachment of smart phones to appropriate Tele Vue eyepieces for "afocal" imaging (Digiscoping). "Afocal" means collimating light between the telescope eyepiece and camera lens.
To minimize vignetting and maximize image quality, see the Eyepiece Specifications table for eyepieces recommended for FoneMate™. Because camera pupils move with zooming, you may find minimum vignetting at the extremes of zoom positions. Results will vary depending on the camera used.