{"product_id":"farpoint-bahtinov-focus-mask-67mm-dslr-lens","title":"Farpoint Bahtinov Focus Mask — 67mm DSLR Lens","description":"\u003c!--FPSEO|v1|20260518|111111111110000010--\u003e\n\u003cp\u003e\u003cstrong\u003eBahtinov focus mask for camera lenses with 67mm filter threads.\u003c\/strong\u003e Snaps into the threads of an inexpensive 67mm UV filter (one-time install). From there, screw the filter onto your lens for a focus check, then unscrew it to shoot — quick and tool-free. Made in our own shop in the USA — American materials, American machinery, by Americans.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eWorks with any DSLR or mirrorless camera lens that takes a 67mm front filter. UV filter sold separately — any inexpensive one will do.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eWhy a Farpoint DSLR lens Bahtinov\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMounts in a 67mm UV filter.\u003c\/strong\u003e Snaps cleanly into the filter threads of any inexpensive 67mm UV filter — focus by screwing the filter on, shoot by screwing it off.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMade in the USA.\u003c\/strong\u003e Designed and manufactured in our own shop with American materials, American machinery, and American workmanship.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIndestructible ABS plastic.\u003c\/strong\u003e Won't crack, warp, or shatter like aluminum or acrylic alternatives. Built to last decades.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e15+ year track record.\u003c\/strong\u003e Farpoint has been making focus masks longer than nearly anyone in the hobby.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat's in the box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1× Farpoint Bahtinov Focus Mask, 67mm filter thread\u003c\/li\u003e\n  \u003cli\u003eInstructions for use\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat you'll need\u003c\/h2\u003e\n\u003cp\u003eAn inexpensive 67mm UV filter, sold separately at any camera shop or online retailer. The Bahtinov mask snaps into the filter's threads — you only have to do this once. From then on, the filter-and-mask combo is what screws on and off your camera lens whenever you need to nail focus.\u003c\/p\u003e\n\n\u003ch2\u003eHow a Bahtinov mask works\u003c\/h2\u003e\n\u003cp\u003eWith the mask snapped into your UV filter, screw the filter onto the front of your lens and aim at a fairly bright star. Take a short exposure. You'll see three diffraction spikes — two angled spikes forming an X, plus a third central spike that's offset to one side or the other when the lens is out of focus. As you adjust the focus ring, the central spike moves across the X. When it lands perfectly centered and symmetrical, you've hit optimum focus. Unscrew the filter and start shooting.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThreading tip:\u003c\/strong\u003e only thread the filter on about half a turn once the threads grab. That's enough to hold it secure for focusing, and makes it quick to remove without overtightening.\u003c\/p\u003e\n\n\u003cp style=\"text-align: center;\"\u003e\n  \u003ciframe title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/bqtRWj1kLgQ\" height=\"315\" width=\"560\" style=\"max-width: 100%;\"\u003e\u003c\/iframe\u003e\n\u003c\/p\u003e\n\n\u003cp style=\"text-align: center;\"\u003e\n  \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0567\/6639\/8617\/files\/bmaskanimation.gif?v=1778193011\" alt=\"Animated GIF showing a star coming into focus through a Bahtinov mask\" width=\"256\" height=\"256\" style=\"display: block; margin: 0 auto;\"\u003e\n  \u003cbr\u003e\u003cem\u003eA star coming into focus through a Bahtinov mask\u003c\/em\u003e\n\u003c\/p\u003e\n\n\u003ch2\u003eFree software for precise focus measurement\u003c\/h2\u003e\n\u003cp\u003eIf you want machine-precise focus instead of eyeballing the spike pattern, free open-source software can analyze the diffraction image automatically:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBahtinov-Collimator\u003c\/strong\u003e — a Windows tool that quantifies focus error directly from your image. \u003ca href=\"https:\/\/github.com\/insertnamehere1\/Bahtinov-Collimator\" rel=\"noopener\" target=\"_blank\"\u003eAvailable on GitHub\u003c\/a\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAPT (Astro Photography Tool)\u003c\/strong\u003e — Bahtinov mask analysis is built into APT's image-capture workflow.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp style=\"text-align: center;\"\u003e\n  \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0567\/6639\/8617\/files\/Collimation.jpg?v=1737820356\" alt=\"Screenshot of Bahtinov-Collimator software analyzing a star image\" width=\"551\" height=\"408\" style=\"display: block; margin: 0 auto; max-width: 100%; height: auto;\"\u003e\n  \u003cbr\u003e\u003cem\u003eBahtinov-Collimator analyzing a star image for precise focus measurement\u003c\/em\u003e\n\u003c\/p\u003e\n\n\u003ch2\u003eNeed a different filter thread size?\u003c\/h2\u003e\n\u003cp\u003eWe make Bahtinov masks for filter threads from 52mm up to 82mm, plus square versions for Cokin P\/Z holders and other large filter systems. \u003ca href=\"\/collections\/dslr-camera-focus-masks-focus-masks-telescope-accessories\"\u003eSee all DSLR lens Bahtinov masks →\u003c\/a\u003e\u003c\/p\u003e\n\n\u003ch2\u003eRelated guides\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003ca href=\"\/pages\/focus-masks\"\u003eFocus Masks Buyer's Guide\u003c\/a\u003e — material comparison, custom-fit vs adjustable, choosing the right type\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp style=\"text-align: center;\"\u003e\n  \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0567\/6639\/8617\/files\/DiffSpike.jpg?v=1737826264\" alt=\"Diffraction spike pattern at perfect focus through a Bahtinov mask\" style=\"display: block; margin: 0 auto; max-width: 100%; height: auto;\"\u003e\n  \u003cbr\u003e\u003cem\u003eThe unmistakable diffraction spike pattern at perfect focus\u003c\/em\u003e\n\u003c\/p\u003e","brand":"Farpoint","offers":[{"title":"Default Title","offer_id":40161511080089,"sku":"FP441","price":16.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0567\/6639\/8617\/products\/Square-FP439_91a78e73-b5b4-4941-853a-528f71f20faa.jpg?v=1625071828","url":"https:\/\/farpointastro.com\/products\/farpoint-bahtinov-focus-mask-67mm-dslr-lens","provider":"FarpointAstro","version":"1.0","type":"link"}