Bahtinov Focus Masks — Fast, Repeatable Focus for Astrophotography
A Bahtinov mask is one of the quickest ways to nail critical focus. Place the mask over the front of your telescope, point at a bright star, and adjust focus until the diffraction spikes align—then remove the mask and start imaging.
Starfield focus masks are laser cut from acrylic and made in-house using Canadian-made materials for consistent fit and repeatable results night after night.
Choose Your Size
Select the mask that matches your telescope’s objective diameter (refractors) or the front opening you’ll mount the mask over. If you’re between sizes, measure the outside diameter of the dew shield or front cell to confirm the best fit.
Quick tip: You’ll get the most accurate focusing when you use a bright star and make small adjustments. Once the central spike is centered between the other two spikes, you’re in focus.
Shop Focus Masks by Optics Size
FAQ
What does a Bahtinov mask do?
It creates diffraction spikes on a bright star so you can visually confirm when you’ve reached precise focus. When the central spike is centered between the other two spikes, focus is dialed in.
Is a Bahtinov mask only for astrophotography?
It’s most popular for imaging because it’s fast and repeatable, but it can also help visual users who want to confirm focus accurately—especially with fast optics.
How do I choose the correct size?
Choose the mask that matches your telescope’s objective diameter (or the opening you’ll mount it over). If you’re unsure, measure the outside diameter of your dew shield/front cell for the best fit.
