StarField Bahtinov Mask - 60 mm - FM-60 Global recommendation This Starlight Innovation Star-Chair IV

This Starlight Innovation Star-Chair IV is specifically designed to provide secure and comfortable seating for astronomical observations as well as other optical tasks

and Operating Instructions

Thread: 1/4 20

The B1800 is good for visual use and photography with standard sensors

StarField Bahtinov Mask - 60 mm - FM-60 Global recommendation This Starlight Innovation Star-Chair IVThis StarField Bahtinov Mask is sized for 60 mm optics. While basic, often home made focus masks have been used for quite some time, the Bahtinov mask, with it's distinctive pattern, is unique. Invented by Russian amateur astronomer Pavel Bahtinov, this mask has quickly become the astro imager's choice for fine focusing a telescope. To use, place the Bahtinov mask in front of the main optics of your scope and take a picture to see the diffraction