Focusing Mask Tri-Bahtinov Celestron SC925

The focusing mask according to Pavel Bahtinov facilitates precise focusing, which is particularly important in astrophotography. The mask is attached to the front of the tube or lens. When looking at a star, it produces a pattern of rays. When the long ray intersects the two slightly shorter rays symmetrically in the middle, the focus is correct. Thanks to its many opening slits, the Bahtinov mask can also be used with relatively dim stars. This is an advantage over the classic Scheiner mask.

A Bahtinov mask should actually be calculated separately for each aperture ratio. However, experience shows that one mask can be used very effectively for an entire aperture range.

Thanks to its two-piece design, the mask can be easily attached to the front of the telescope – even if a Hyperstar system with a camera and cables is already installed. Both halves of the mask connect precisely and securely via integrated magnetic connections.

This eliminates the need for the cumbersome process of fitting a large, single-piece mask over cables and attachments, particularly where space is limited around Hyperstar cameras.

Tri-Bahtinov technology also enables particularly precise collimation and focus control directly on the star. This allows even the smallest deviations to be quickly detected and optimally corrected.

The Tri-Bahtinov mask produces several precise diffraction patterns, thereby enabling particularly accurate control of focus and collimation – ideal for demanding astrophotography, EAA and fast Hyperstar systems.

The item is made from PETG using a 3D printing process and is dimensionally stable up to 80°C.