{"product_id":"starizona-m42-extension-3mm","title":"Starizona M42 Extension - 3mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n  \u003cli\u003eAdds 3mm of spacing to an imaging train\u003c\/li\u003e\n  \u003cli\u003eFeatures M42 male and female threads\u003c\/li\u003e\n  \u003cli\u003eSolid, fixed-length design\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\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 Extension - 3mm\u003c\/h2\u003e\n          \u003cp\u003eThe Starizona M42 Extension provides a simple, rigid solution for adding exactly 3mm of length to an M42-threaded imaging train. This fixed-length spacer is designed to help you achieve the precise back focus required by your field flattener or focal reducer, ensuring sharp stars across your entire image sensor. By threading directly into your existing setup, it offers a secure connection for fine-tuning your optical spacing.\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\u003ePrecision Spacing: The 3mm Back Focus Solution\u003c\/h3\u003e\n          \u003cp\u003eAchieving perfect back focus is critical for astrophotography, and often the final adjustment needed is only a few millimeters. The Starizona 3mm M42 Extension is the ideal tool for this scenario. When your stars are sharp in the center but slightly elongated in the corners, it's a clear sign that your camera sensor is not at the optimal distance from your corrector lens. This spacer bridges that small gap with a solid, non-flexing component, which is often preferable to variable spacers that can introduce tilt. With standard male and female M42 threads, it integrates seamlessly into most common imaging setups.\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 primary use for the Starizona M42 Extension - 3mm?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eThis extension is used to add a precise \u003cstrong\u003e3mm\u003c\/strong\u003e of distance in an astrophotography imaging train. This helps you achieve the exact back focus distance specified by a focal reducer or field flattener, which is necessary for creating sharp, point-like stars across the entire field of view.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat threads does the Starizona M42 Extension use?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eThe extension features standard \u003cstrong\u003eM42\u003c\/strong\u003e threads, with one male side and one female side. This allows it to be inserted between two other M42-threaded components, such as a camera T-ring and a reducer.\u003c\/p\u003e\n    \u003c\/div\u003e\n     \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWhy use a fixed 3mm Starizona M42 spacer instead of an adjustable one?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eWhen you know you only need a small, specific amount of spacing like 3mm, a fixed spacer provides a more rigid and stable connection. Unlike some adjustable spacers, a solid extension has zero chance of introducing optical tilt, ensuring your camera sensor remains perfectly perpendicular to the light path.\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\u003eThreads\u003c\/td\u003e\n          \u003ctd\u003eM42 (male\/female)\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eExtension Length\u003c\/td\u003e\n          \u003ctd\u003e3mm\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\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":68045007225117,"sku":"STZ-EXTM42-3","price":10.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Starizona-M42-Extension-1_369c85dd-e638-4d5d-8014-ab9461343907.jpg?v=1794410549","url":"https:\/\/davidastro.com\/products\/starizona-m42-extension-3mm","provider":"David Astro","version":"1.0","type":"link"}