|TeleVue.com: Telescope Accessories > Starbeam > Background|
Viewed straight through, you see the natural sky with a 10 arc-minute (1/3 Moon diameter) "red-star" showing your scope's position. When your scope is pointed high, flip the mirror into position for more comfortable viewing. Viewed this way, the sky orientation matches a refractor or SCT's image. The adjustable brightness and blink-rate of the "red-star" makes it easy to see against any twilight to dark sky background.
With its 39mm aperture, the projected image is easily seen any distance behind Starbeam, whether 2 inches or 2 feet! The finely made glass lens acts as a beamsplitter to combine the natural sky background with the superimposed red pointing "star." The first lens surface acts as a collimating mirror so the "red-star" stays stationary against the sky background regardless of how it is viewed. It's 6-arc-minute accuracy over any eye position allows you to pin-point objects -- even with high-power eyepieces in the telescope. A compensating curve is designed into the second lens surface to provide the normal sky background view and is multi-coated to eliminate double images.
Elegant in design and form, Starbeam is custom machined completely from aluminum and then black anodized, even down to the "push-pull" thumb screws. No tools are required to align Starbeam with your telescope. Mounting hardware included.