{"product_id":"william-optics-flat-61a-field-flattener","title":"William Optics FLAT 61A Field Flattener","description":"\u003cp\u003eThe \u003cstrong\u003eWilliam Optics FLAT 61A\u003c\/strong\u003e is a 1.0x field flattener designed to improve edge-to-edge star sharpness when imaging with compatible William Optics refractors, especially the Zenithstar 61. It helps correct field curvature so astrophotographers can capture cleaner stars across APS-C and full-frame camera sensors.\u003c\/p\u003e\u003ch2\u003eWho Is This Product Best For?\u003c\/h2\u003e\u003cp\u003eThe FLAT 61A is best for astrophotographers using a Zenithstar 61 or compatible small William Optics refractor who want a flatter imaging field for deep-sky photography.\u003c\/p\u003e\u003ch2\u003eWhy Choose This Product?\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.0x correction:\u003c\/strong\u003e Flattens the field without reducing focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAPS-C and full-frame support:\u003c\/strong\u003e Designed for common astronomy and DSLR\/mirrorless camera setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera adapter support:\u003c\/strong\u003e Uses an M48 camera-side thread and supports common T-mount ecosystems.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eRecommended Uses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eWide-field deep-sky astrophotography\u003c\/li\u003e\n\u003cli\u003eImproving star shape at the edge of the frame\u003c\/li\u003e\n\u003cli\u003eZenithstar 61 imaging setups\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility and Accessory Notes\u003c\/h2\u003e\u003cp\u003eUse the recommended back focus spacing for your telescope and camera. Customers should confirm camera adapter, T-ring, and spacing requirements before imaging.\u003c\/p\u003e\u003ch2\u003eImportant Limitations\u003c\/h2\u003e\u003cp\u003eThis is an imaging accessory, not a visual observing accessory. Correct spacing is required for best results.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003ch3\u003eDoes the FLAT 61A reduce focal length?\u003c\/h3\u003e\u003cp\u003eNo. It is a 1.0x field flattener.\u003c\/p\u003e\u003ch3\u003eWhich telescope is it mainly for?\u003c\/h3\u003e\u003cp\u003eIt is primarily intended for Zenithstar 61 imaging systems.\u003c\/p\u003e\u003ch2\u003eOur Recommendation\u003c\/h2\u003e\u003cp\u003eChoose the FLAT 61A if you image with a Zenithstar 61 and want cleaner corner stars without changing the telescope’s focal length.\u003c\/p\u003e","brand":"William Optics","offers":[{"title":"Default Title","offer_id":53154238627951,"sku":"P-FLAT61A-NEW","price":320.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/william-optics-flat-61a.jpg?v=1779654739","url":"https:\/\/ontariotelescope.com\/products\/william-optics-flat-61a-field-flattener","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}