The Vixen VSD100F3.8 astrograph, a 4-inch telescope, was first showcased at the 2013 Advanced Imaging Conference. A notable feature of the telescope is its large, non-rotating helical focuser designed ...

Celestron’s Off-Axis Guider uses an adjustable, multicoated 12.5-millimeter prism that allows you to locate a guide star. It has a fixed-orientation helical focuser and includes all needed spacers and ...