Large Bahtinov Focus Tool for 10 inch Telescopes

Show some love for the big boys!

So you've got a 10-inch telescope? Nice, man. You're gonna need a big bahtinov for that. 

We got you covered.

10-inch Bahtinov Focus Masks for Large Telescopes. 

Bahtinov Focus Tool for Telescopes with a front, exterior diameter of 250-270mm.

Place the Bahtinov Focus-Mask over the end of your telescope, then locate a bright star near your target, take a 3-5 second picture and view the diffraction spikes. Change your focus, take another picture, and again, view your diffraction spikes. Is the center spike moving further from the center? Then change the direction your focusing and try another picture.

Watch the direction the spikes are moving and when the center spike passes the middle of the other two spikes, change direction and fine-tune your tuning knobs until the center spike is in the middle. You are now in perfect focus!

This product is NOT a medical device.