{"product_id":"celestron-m42-spacer-ring-kit","title":"Celestron M42 Spacer Ring Kit","description":"\u003ch2\u003eCelestron M42 Spacer Ring Kit\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePrecise Backfocus Adjustment for Optimal Image Quality\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAchieving pinpoint star sharpness in astrophotography relies on setting the correct \u003cstrong\u003ebackfocus distance\u003c\/strong\u003e between your camera sensor and telescope optics. The \u003cstrong\u003eCelestron M42 Spacer Ring Kit\u003c\/strong\u003e makes this easy, ensuring optimal edge-to-edge performance—especially for full-frame imaging sensors.\u003c\/p\u003e\n\u003ch3\u003eWhy Backfocus Matters\u003c\/h3\u003e\n\u003cp\u003eIf your camera sits too close or too far from the telescope's required focus point, stars near the corners of your frame can appear distorted or elongated. Spacer rings fine-tune this distance, helping maintain the RASA, EdgeHD, or Schmidt-Cassegrain system’s intended performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eExample:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eRASA 8 + ZWO ASI 183MC Pro\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eRequired backfocus: 25mm\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCamera depth: 17.5mm\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNeeded spacer: \u003cstrong\u003e7.5mm M42 ring\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat’s Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e3x Precision CNC-machined spacer rings:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e7.5mm\u003c\/strong\u003e – Ideal for many ZWO cameras on RASA 8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e12mm\u003c\/strong\u003e – Ideal for many Atik cameras on RASA 8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e30mm\u003c\/strong\u003e – Converts ZWO camera with filter slider to 55mm backfocus standard (Schmidt-Cassegrain \u0026amp; EdgeHD)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow to Use\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWith DSLR:\u003c\/strong\u003e Insert the appropriate ring between your T-Ring and T-Adapter.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWith CMOS\/CCD:\u003c\/strong\u003e Place the ring between your camera and the T-Adapter.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBuild Quality\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eAnodised machined aluminium construction\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eGlare-threaded, blackened interior for maximum contrast\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eKnurled edges\u003c\/strong\u003e for easy grip when threading or removing\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCompatible with \u003cstrong\u003eM42 x 0.75 (T-thread)\u003c\/strong\u003e camera adapters\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe Celestron M42 Spacer Ring Kit is an essential accessory for anyone seeking the sharpest, most accurate astroimages possible—especially when using full-frame or sensitive CMOS imaging cameras.\u003c\/p\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":55897343689078,"sku":"050234936187","price":49.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2235\/3014\/files\/CelestronM42SpacerRingKit-1.webp?v=1758552088","url":"https:\/\/welshastronomy.co.uk\/products\/celestron-m42-spacer-ring-kit","provider":"The Welsh Astronomy Centre","version":"1.0","type":"link"}