The unique design of the Tele Vue Starbeam 1x39 Finderscope offers two modes of use: straight-through line-of-sight, or 90° angled viewing when the optical tube assembly (OTA) is pointed high overhead at or near the zenith. A mirror flips up for a more comfortable viewing angle when the tube is pointed up, and simply folds down when the OTA is pointed more parallel to the ground.
This scope is configured as an unmagnified finder with a larger 39mm aperture for a wide field of view and a 6 arc-min accuracy. In its straight-through setting, you see the natural sky with a 10 arc-minute field of view, and when using the mirror flipped up, the sky orientation is the same as when viewing through the scope's eyepiece. A center red-dot reticle helps with precise positioning and controls allow the brightness and blink rate to be adjusted.
Included with the Starbeam is a mounting bracket with a base curvature that fits 4", and larger, Newtonian reflectors and slotted holes positioned to accommodate a wide variety of accessory holes found on popular models—mounting screws will need to be acquired separately for proper installation. A dovetail plate on the Starbeam simply slides into the bracket for fast installation and removal.