TRI-Bahtinov Focus Mask - Celestron Guidescope A review of calibration frames

A review of calibration frames     85

including IR and UV light

no-tool set up

178 LCD: Red backlit 4 Line LCD CPU: STMicro ARM 32-bit Cortex™-M3 CPU Software and Firmware: Fully upgradable RS-232 Port: PC connectable for software/firmware upgrades

and a few more of the most famous celestial objects

TRI-Bahtinov Focus Mask - Celestron Guidescope A review of calibration framesWhat is the Tri Bahtinov? Essentially three Bahtinov masks in one, rotated over 120 degrees. It gives you three lines and three crosses to check focus and collimation, along three axis simultaneously. In addition to focusing, the Tri Bahtinov so also indicates collimation status along three axis. This is interesting for e. g. Schmidt Cassegrain telescopes, where the collimation is done by push pull screws of the secondary mirror along three axis. When