This Telescope T-Adapter Photo Fitting is used in conjunction with a T-Ring to connect an analog or digital SLR camera to a Celestron EdgeHD 800 telescope. This fitting is only compatible with the Celestron EdgeHD 800 telescope. This configuration is used for terrestrial and short exposure photography, for direct focus photography of the Sun and Moon and especially for long exposure deep sky photography when using an off-axis guider or separate guide scope.