{"product_id":"daystar-quark-visual-focal-reducer","title":"Daystar QUARK Visual Focal Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eNominal Focal Reduction Factor\u003c\/li\u003e\n\u003cli\u003eDesigned Exclusively for Daystar Quark Filters\u003c\/li\u003e\n\u003cli\u003eWidens the True Field of View\u003c\/li\u003e\n\u003cli\u003eIncreases Image Brightness for Prominence Detail\u003c\/li\u003e\n\u003cli\u003eThreads Directly Between Quark and Eyepiece\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\u003eDownloads\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\u003eDaystar QUARK Visual Focal Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Daystar QUARK Visual Focal Reducer is an essential accessory for your Daystar Quark H-alpha filter, designed to widen your field of view and significantly brighten the solar image. This reduction in focal length makes faint, ethereal prominences pop with greater contrast and allows you to frame more of the solar disc in a single view, especially in longer focal length telescopes.\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\u003eA Wider, Brighter View of the Sun\u003c\/h3\u003e\n\u003cp\u003eBy shortening your telescope's effective focal length, this reducer delivers two critical advantages for solar observers. It expands your true field of view, allowing you to fit more of the sun's dynamic surface and surrounding corona into the eyepiece. This wider perspective can also be achieved using shorter, often more comfortable, eyepieces than you would typically use.\u003c\/p\u003e\n\u003cp\u003eCrucially, the focal reduction concentrates sunlight, increasing the brightness of the image. This effect is invaluable for teasing out faint, delicate prominence structures that might otherwise be invisible against the blackness of space. The enhanced brightness can reveal greater extent and detail in these faint features.\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\u003eEyepiece Selection: Understanding the \"Porthole Effect\"\u003c\/h3\u003e\n\u003cp\u003eThe performance of the QUARK Visual Focal Reducer is highly dependent on eyepiece selection. Eyepieces with a field stop positioned at or above the end of the drawtube can cause a more extreme focal reduction, which may lead to blurring at the edges of the field.\u003c\/p\u003e\n\u003cp\u003eThis configuration can also create a constrained exit pupil, resulting in a narrow \"porthole effect.\" This makes it difficult for an observer to position their eye correctly to see the full field, an issue that is particularly challenging during public outreach events. Daystar recommends experimenting with a variety of eyepieces to find the best optical match for your specific observing goals.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Daystar QUARK Visual Focal Reducer do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt reduces the effective focal length of your telescope when using a Daystar Quark filter. This provides a \u003cstrong\u003ewider true field of view\u003c\/strong\u003e and a \u003cstrong\u003ebrighter solar image\u003c\/strong\u003e, making it easier to see the entire solar disc and faint prominence details.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the QUARK Visual Focal Reducer improve views of solar prominences?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eBy concentrating the light into a smaller area, the reducer increases the surface brightness of the image. This added brightness provides more contrast, helping faint and delicate solar prominences stand out more clearly against the dark background of space.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Daystar QUARK Visual Focal Reducer work with any eyepiece?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile it is physically compatible with standard eyepieces, optical performance can vary. Eyepieces with high field stops may produce edge-of-field blurring or a \"porthole effect\" that makes eye placement difficult. Experimentation is recommended to find the best pairing for your setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the \"porthole effect\" and how do I avoid it with the Daystar QUARK Visual Focal Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \"porthole effect\" is a narrow, constricted view that makes it hard to position your eye to see the entire field. It can be caused by certain eyepiece designs when used with the reducer. To avoid it, experiment with different eyepieces, particularly those with field stops located deeper inside the barrel, to find one that provides a wide, comfortable exit pupil.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI'm using the Daystar QUARK Visual Focal Reducer with a long focal length SCT. Will it let me see the full solar disc?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, that is one of its primary applications. In long focal length instruments like Schmidt-Cassegrains or Maksutovs, the reducer widens the field of view enough that you can often frame the entire sun, which is typically impossible at the telescope's native focal length with a Quark filter installed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eFor public outreach with my refractor and Daystar Quark, what's the best way to use the Visual Focal Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor public outreach, ensuring a comfortable view is critical. Before the event, test several different eyepieces with the Daystar QUARK Visual Focal Reducer to find a combination that produces a wide, bright exit pupil and avoids the \"porthole effect.\" A view that is easy for a novice observer to look through will make the experience much more enjoyable.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/daystar-filters-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eDaystar Filters Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Daystar Filters","offers":[{"title":"Default Title","offer_id":52935164690717,"sku":"DAY-FRQVQ","price":279.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/DaystarFilters-Daystar-QUARK-Visual-Focal-Reducer-1_6ca1a88a-f12a-4105-bcdb-e4573b408ffd.jpg?v=1789520773","url":"https:\/\/davidastro.com\/products\/daystar-quark-visual-focal-reducer","provider":"David Astro","version":"1.0","type":"link"}