Description Invented in 2008 by Pavel Bahtinov, these “fishbone calibrators” or “Bahtinov Mask” work by showing a very distinct visual pattern when pointed at a bright star and when you have adjusted to perfect focus. This fantastic invention is an essential for astro-photographers or visual astronomers to know that they are getting the best possible image! Astro Dog’s Bahtinov Masks are light, won’t rust (made of light, hard plastic) are precisely engineered and form a lovely, clear and distinct pattern. You’ll love it. This product was compared head to head by the SRAA (Scenic Rim Astronomy Association) and came up providing the same performance as the Orion brand. Note that the fit is somewhat adjustable so that it will fit a bit over and under the given size. This mask is large. It is especially shipped in a large box so that it arrives safely and is considered a bulky shipment. Please choose the 9.95 postage option on checkout.
