{"product_id":"starizona-m42-spacer-7-5mm","title":"Starizona M42 Spacer - 7.5mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n  \u003cli\u003eAdds 7.5mm of Spacing to an Optical Train\u003c\/li\u003e\n  \u003cli\u003eM42 Male to M42 Female Threads\u003c\/li\u003e\n  \u003cli\u003eFixed, Non-Adjustable Length\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n    \u003cdiv\u003e\n      \u003cdiv class=\"DAV-bg-light\"\u003e\n        \u003cdiv class=\"DAV-section-center\"\u003e\n          \u003ch2\u003eStarizona M42 Spacer - 7.5mm\u003c\/h2\u003e\n          \u003cp\u003eThe Starizona M42 Spacer provides a fixed, precise extension of 7.5mm for imaging trains that use M42 threads. This 7.5mm length is essential for achieving the exact back focus distance required by many field flatteners and focal reducers, ensuring your optical system delivers sharp stars across the entire sensor.\u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"DAV-bg-light\"\u003e\n        \u003cdiv class=\"DAV-section\"\u003e\n          \u003ch3\u003eAchieving Precise 7.5mm Back Focus\u003c\/h3\u003e\n          \u003cp\u003eIn astrophotography, connecting a camera, filter wheel, and off-axis guider to a telescope often results in an optical path length that doesn't match the specific requirements of your corrector optics. This Starizona spacer closes a 7.5mm gap with a single, rigid component.\u003c\/p\u003e\n          \u003cp\u003eBy inserting this M42-to-M42 spacer, you can confidently hit your target back focus without the complexity or potential for tilt that can come from stacking multiple thin shims or using adjustable adapters. It is a simple, robust solution for a very specific and common spacing problem in M42-based imaging systems.\u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/li\u003e\n\n\u003cli\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the function of the Starizona M42 7.5mm Spacer?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eThis spacer adds exactly \u003cstrong\u003e7.5mm\u003c\/strong\u003e of length to your M42-threaded imaging train. Its purpose is to help you achieve the precise back focus distance (the distance from the corrector lens to the camera sensor) required by your field flattener or focal reducer for optimal performance.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the thread and length specifications for this M42 spacer?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eThe Starizona M42 Spacer has \u003cstrong\u003eM42\u003c\/strong\u003e threads on both ends (typically male on one and female on the other) and provides a fixed extension length of \u003cstrong\u003e7.5mm\u003c\/strong\u003e.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I know if I need a 7.5mm spacer for my setup?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eYou need a 7.5mm spacer if the total back focus of your current imaging train (camera flange distance + adapters) is 7.5mm less than the distance required by your flattener or reducer. You can determine this by adding up the specified optical lengths of all components in your train and subtracting that total from the required back focus of your corrector.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/li\u003e\n\n\u003cli\u003e\n    \u003ctable class=\"DAV-specifications\"\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eThread\u003c\/td\u003e\n          \u003ctd\u003eM42 to M42\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eLength\u003c\/td\u003e\n          \u003ctd\u003e7.5mm\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/li\u003e\n\n\u003cli\u003e\n    \u003cul class=\"DAV-grid\"\u003e\n      \u003cli class=\"DAV-grid-item\"\u003e\n        \u003cdiv\u003e\n          \u003cp class=\"DAV-item-title\"\u003eStarizona M42 Spacer (7.5mm)\u003c\/p\u003e\n          \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/starizona-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eStarizona Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Starizona","offers":[{"title":"Default Title","offer_id":68045014401309,"sku":"STZ-EXT-M42-75","price":14.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Starizona-M42-Spacer-2_224a7fa7-e395-4dc6-afdc-8cea75d991a6.jpg?v=1794410570","url":"https:\/\/davidastro.com\/en-us\/products\/starizona-m42-spacer-7-5mm","provider":"David Astro","version":"1.0","type":"link"}