Tri-Bahtinov masks
Tri-Bahtinov masks that we laser-cut in Shropshire from black acrylic. Three Bahtinov patterns, set at 120° to each other, show focus and collimation on one star. They’re especially useful on Schmidt-Cassegrains and other telescopes that need collimating.
How a tri-Bahtinov mask works
On a bright star, each pattern makes its own set of spikes. When all three middle spikes are centred, the telescope is in focus. If you can’t centre all three at once, the optics need collimating, and the spikes show which way.
Made for your telescope
Each tri-Bahtinov mask is made for a particular telescope. If yours isn’t listed, we can make one to order. Call 01743 224 180 or get in touch and we’ll talk through the design.