{"title":"Explore Scientific Visual Accessories","description":"\u003cp\u003eExplore Scientific visual accessories cover the parts between the focuser and the eyepiece. The range includes 99% reflective diagonals in 2\" and 3\" sizes, Focal Extenders in 2x, 3x and 5x versions for 1.25\" and 2\" eyepieces, and a BinoViewer for observing with both eyes.\u003c\/p\u003e\u003cp\u003eFocal Extenders raise magnification for the Moon, planets and double stars without changing eyepieces, while the large diagonals suit refractors and SCTs fitted with wide 2\" or 3\" focusers.\u003c\/p\u003e","products":[{"product_id":"explore-scientific-2x-focal-extender-1-25","title":"Explore Scientific 2x Focal Extender - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDoubles the magnification of any 1.25\" eyepiece\u003c\/li\u003e\n\u003cli\u003eTelecentric optical design ensures a true 2x power factor\u003c\/li\u003e\n\u003cli\u003eMaintains the original eye relief of the eyepiece in use\u003c\/li\u003e\n\u003cli\u003eImproves image quality compared to standard Barlow lenses\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\u003eExplore Scientific 2x Focal Extender - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 2x Focal Extender doubles the power of any 1.25\" eyepiece, effectively turning your existing accessory case into a collection with twice the magnification options. Its advanced telecentric optical design delivers a consistent and true 2x magnification factor, a critical advantage over traditional Barlow lenses, especially for astrophotography.\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\u003eTelecentric Design: A Stable 2x Magnification Factor\u003c\/h3\u003e\n\u003cp\u003eUnlike a standard Barlow, which uses a negative lens group, the Explore Scientific Focal Extender employs a multi-element telecentric design. This system produces light rays that exit parallel to the optical axis, ensuring the 2x magnification remains constant regardless of the distance to the eyepiece or camera sensor. This provides predictable, sharp, and evenly illuminated views across the entire field, which is essential for consistent results in both visual observation and imaging.\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\u003e2x Power While Preserving Eyepiece Eye Relief\u003c\/h3\u003e\n\u003cp\u003eOne of the most significant ergonomic benefits of this focal extender is its ability to preserve the native eye relief of your eyepiece. Lower-power eyepieces typically have more generous eye relief, and by using the 2x extender, you can achieve high magnification while enjoying that same comfortable viewing distance. This makes high-power observing sessions more accessible and comfortable, especially for those who wear glasses.\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\u003eFocal Extender vs. Traditional Barlow: Why Telecentric Matters\u003c\/h3\u003e\n\u003cp\u003eThe choice between a focal extender and a Barlow lens comes down to optical stability and intended use. While both increase magnification, their methods differ significantly, leading to different outcomes.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTraditional Barlow Lens:\u003c\/strong\u003e A Barlow's magnification can vary depending on how far the eyepiece is spaced from the lens. This can be useful for fine-tuning image scale but introduces unpredictability. The diverging light cone can also induce vignetting and degrade edge-of-field sharpness, especially in fast telescopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExplore Scientific Focal Extender:\u003c\/strong\u003e The telecentric design provides a fixed, true 2x magnification that does not change with spacing. Its parallel light path is much gentler on complex eyepieces, preserving their designed optical corrections and maintaining image quality from the center to the edge of the field. This makes it the superior choice for imaging and for observers who demand consistency.\u003c\/li\u003e\n\u003c\/ul\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 is the main advantage of the Explore Scientific 2x Focal Extender over a standard 2x Barlow?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is its \u003cstrong\u003etelecentric optical design\u003c\/strong\u003e. This ensures a true, fixed 2x magnification regardless of eyepiece or camera spacing, providing more consistent and predictable results than a traditional Barlow lens, whose magnification can fluctuate with distance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Explore Scientific 2x Focal Extender help observers who wear eyeglasses?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis focal extender preserves the original eye relief of the eyepiece you pair it with. You can use a comfortable, long-eye-relief, low-power eyepiece to achieve high magnification, allowing you to keep your glasses on and still see the entire field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have a 25mm eyepiece for my 8\" f\/10 SCT. What will the Explore Scientific 2x Focal Extender do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn a typical 8\" f\/10 SCT with a 2032mm focal length, your 25mm eyepiece provides about 81x magnification. Adding the Explore Scientific 2x Focal Extender will double that to approximately 162x, giving you a much closer view of planetary detail on objects like Jupiter or Saturn, all while you continue to use your comfortable 25mm eyepiece.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Explore Scientific 2x Focal Extender to image Jupiter with my planetary camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The telecentric design is ideal for planetary imaging. It increases your telescope's effective focal length by a precise 2x factor, enlarging the planet on your camera sensor without introducing the optical aberrations that can occur with standard Barlow lenses in an imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Explore Scientific 2x Focal Extender work with my specialty eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the parallel light path from the telecentric design is much more forgiving on complex, wide-field eyepieces than the steep light cone from a Barlow. It helps maintain the high-quality performance your premium eyepieces were designed to deliver, even at double the power.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes adding the Explore Scientific 2x Focal Extender reduce image brightness?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAny time you increase magnification, the image will become dimmer because the same amount of light is spread over a larger area. While the multi-coated optics in the focal extender are highly efficient, the dimming you perceive is a direct and unavoidable consequence of the 2x increase in magnification, not a loss of light through the device itself.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e8122570104178\u003c\/td\u003e\n\u003c\/tr\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\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198392605,"sku":"ES-FE02-125","price":167.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-1-25-inch-2x-Focal-Extender-FE02-125-1__57406.1594240336.1280.1280.jpg?v=1684338801"},{"product_id":"explore-scientific-3x-focal-extender-1-25","title":"Explore Scientific 3X Focal Extender - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eInstantly triples the magnification of any 1.25\" eyepiece\u003c\/li\u003e\n\u003cli\u003eTelecentric optical design provides consistent magnification\u003c\/li\u003e\n\u003cli\u003eMaintains the eye relief of the original eyepiece\u003c\/li\u003e\n\u003cli\u003eImproves image quality compared to standard Barlow lenses\u003c\/li\u003e\n\u003cli\u003eIdeal for high-power planetary viewing and imaging\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\u003eExplore Scientific 3X Focal Extender - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 3X Focal Extender instantly triples the power of any 1.25\" eyepiece in your collection. This telecentric design turns three of your favorite low-power eyepieces into a versatile set offering six distinct magnifications, unlocking high-power views without sacrificing optical integrity or viewing comfort.\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\u003eTriple Your Magnification with a 1.25\" Barrel\u003c\/h3\u003e\n\u003cp\u003eThis focal extender multiplies the utility of your existing eyepiece case. By inserting this 3X extender, you can achieve magnifications typically reserved for short focal length eyepieces, which often have tight, uncomfortable eye relief. It allows you to push the power on clear nights to resolve fine detail on Jupiter's cloud bands or split tight double stars, all while using your familiar, comfortable long-focal-length eyepieces.\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\u003eTelecentric Optics: A Stable 3X Magnification Factor\u003c\/h3\u003e\n\u003cp\u003eUnlike a traditional Barlow lens, the Explore Scientific Focal Extender uses a multi-element telecentric design. This system ensures light rays exit parallel to the optical axis, delivering a true, fixed 3X magnification regardless of the distance between the extender and your eyepiece or camera sensor. This stability is critical for astrophotography, where precise focal length is required for accurate image scaling, and it eliminates the variable magnification that can occur with Barlows.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsistent Magnification:\u003c\/strong\u003e The 3X power factor remains constant, providing predictable and repeatable results for both visual observation and imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaintained Eye Relief:\u003c\/strong\u003e You get to enjoy the generous eye relief of your lower-power eyepiece, a significant advantage for eyeglass wearers and for comfortable extended viewing sessions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved Field Flatness:\u003c\/strong\u003e The telecentric design helps to reduce field curvature, resulting in sharper stars at the edge of the field compared to simpler amplifier lenses.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFocal Extender vs. Barlow: Why the Telecentric Design Matters\u003c\/h3\u003e\n\u003cp\u003eWhile both devices increase magnification, their optical approach is fundamentally different. A standard Barlow's magnification factor changes as you alter its spacing from the eyepiece, which can be unpredictable. The Explore Scientific Focal Extender's telecentric design offers superior optical correction and stability.\u003c\/p\u003e\n\u003cp\u003eThis makes it the preferred choice for observers using premium, complex eyepieces or imagers who require a flat field and consistent focal length. The parallel light path is less demanding on eyepiece optics, preserving the original image quality without introducing additional aberrations.\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 is the main difference between the Explore Scientific 3X Focal Extender and a standard 3X Barlow?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary difference is the \u003cstrong\u003etelecentric optical design\u003c\/strong\u003e of the Focal Extender. This provides a fixed, consistent 3X magnification regardless of spacing. A standard Barlow's magnification can vary depending on its distance from the eyepiece or camera sensor. The telecentric design also better preserves the eye relief of the eyepiece and provides superior optical correction across the field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the 3X Focal Extender affect my view of Saturn in an 8\" f\/10 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn an 8\" f\/10 SCT (2032mm focal length), a 25mm eyepiece gives you 81x magnification. Adding the Explore Scientific 3X Focal Extender will increase that to 243x. This is an excellent magnification for resolving details like the Cassini Division in Saturn's rings and observing cloud bands on the planet itself, assuming steady atmospheric conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Explore Scientific 3X Focal Extender change the eye relief of my eyepiece?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA key benefit of the telecentric design is that it largely \u003cstrong\u003epreserves the original eye relief\u003c\/strong\u003e of the eyepiece you use it with. This means you can achieve high power while still enjoying the comfortable, long eye relief of a lower-power eyepiece, which is especially beneficial for eyeglass wearers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 3X Focal Extender a good choice for planetary imaging with a high-frame-rate camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is an excellent choice. The telecentric design provides a flat field and ensures the magnification is a consistent 3X, which is critical for planetary imaging. It effectively triples your telescope's focal length, increasing the image scale on your camera sensor to make planets like Jupiter, Saturn, and Mars appear larger and more detailed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 1.25\" focal extender work with my 2\" eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this model is designed specifically for \u003cstrong\u003e1.25\" eyepieces and accessories\u003c\/strong\u003e. It will not fit 2\" eyepieces. You must use eyepieces with a 1.25\" barrel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs there a downside to using the Explore Scientific 3X Focal Extender?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eLike any device that triples magnification, the 3X Focal Extender will result in a dimmer image and make your telescope more sensitive to atmospheric instability (seeing). It requires good seeing conditions to deliver its best results. However, its superior optical design minimizes aberrations compared to simpler Barlow lenses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification\u003c\/td\u003e\n\u003ctd\u003e3X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTelecentric\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e812257010394\u003c\/td\u003e\n\u003c\/tr\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\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198458141,"sku":"ES-FE03-125","price":195.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-1-25-inch-3X-Focal-Extender-FE03-125-1__93025.1594240336.1280.1280.jpg?v=1684338802"},{"product_id":"explore-scientific-5x-focal-extender-1-25","title":"Explore Scientific 5X Focal Extender - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDelivers a 5X magnification increase to any 1.25\" eyepiece\u003c\/li\u003e\n\u003cli\u003e1.25\" barrel diameter fits standard focusers and accessories\u003c\/li\u003e\n\u003cli\u003eTelecentric optical design provides consistent, true-to-spec magnification\u003c\/li\u003e\n\u003cli\u003eMaintains the original eye relief of the eyepiece for comfortable viewing\u003c\/li\u003e\n\u003cli\u003eIdeal for high-resolution planetary imaging and visual observation\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\u003eExplore Scientific 5X Focal Extender - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 5X Focal Extender multiplies the power of any 1.25\" eyepiece by a factor of 5, transforming a basic eyepiece collection into a versatile high-power toolkit. Its advanced telecentric optical design maintains the comfortable eye relief of your lower-power eyepieces, delivering a significant jump in magnification without the typical eye strain associated with short focal length designs.\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\u003e5X Power: A Major Leap in Magnification\u003c\/h3\u003e\n\u003cp\u003eA 5X power increase provides the high magnification needed to resolve fine details on planetary surfaces, split tight double stars, and examine the structure of small planetary nebulae. This focal extender effectively adds a new, very high-power option for every eyepiece you own, expanding your observing capabilities without requiring a whole new set of dedicated high-magnification eyepieces.\u003c\/p\u003e\n\u003cp\u003eThis significant boost in magnification will result in a dimmer image, a necessary trade-off for increased image scale. For this reason, the 5X Focal Extender performs best on bright targets like the Moon, Jupiter, Saturn, and Mars, where light grasp is plentiful.\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\u003eTelecentric Design: Consistent 5X Magnification for Imaging \u0026amp; Visual\u003c\/h3\u003e\n\u003cp\u003eUnlike a traditional Barlow lens, the Explore Scientific Focal Extender uses a telecentric design. This multi-element system ensures light rays exit the extender parallel to the optical axis, which results in a fixed, true-to-spec magnification factor regardless of the distance between the extender and the eyepiece or camera sensor.\u003c\/p\u003e\n\u003cp\u003eThis consistency is critical for astrophotography. Whether you add a filter wheel or an off-axis guider, the image scale remains a predictable 5X. For visual observers, this design contributes to sharp performance across the entire field of view, especially in faster 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\u003ePreserving Eye Relief: High Power Without the Discomfort\u003c\/h3\u003e\n\u003cp\u003eHigh-power eyepieces are notoriously difficult to look through, often featuring very short eye relief that forces you to press your eye against the lens. The 5X Focal Extender solves this problem by allowing you to use your comfortable, long-eye-relief, low-power eyepieces for high-magnification views.\u003c\/p\u003e\n\u003cp\u003eYou can insert a 25mm Plössl with 15mm of eye relief and get the power of a 5mm eyepiece while retaining that comfortable 15mm of eye relief. This is a significant advantage for all observers and is especially beneficial for those who wear glasses.\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\u003eFocal Extender vs. Traditional Barlow Lens: Why Telecentric Matters\u003c\/h3\u003e\n\u003cp\u003eWhile a conventional Barlow lens is a simple and effective way to increase magnification, its performance is variable. A Barlow's magnification factor changes depending on its distance from the eyepiece, making it difficult to achieve a precise, repeatable image scale. The telecentric Focal Extender, by contrast, delivers a constant 5X magnification factor.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePredictable Magnification:\u003c\/strong\u003e The extender's 5X power is fixed, which is essential for calculating image scales in planetary imaging setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved Edge Correction:\u003c\/strong\u003e The parallel light rays from the telecentric design often result in sharper star images at the edge of the field compared to a simple Barlow, particularly in telescopes with fast focal ratios.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaintained Eye Relief:\u003c\/strong\u003e The Focal Extender is explicitly designed to preserve the eye relief of the eyepiece it's paired with, a feature not always prioritized in standard Barlow designs.\u003c\/li\u003e\n\u003c\/ul\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 is the main advantage of the Explore Scientific 5X Focal Extender over a standard 5X Barlow?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is its \u003cstrong\u003etelecentric design\u003c\/strong\u003e. This ensures the Explore Scientific 5X Focal Extender provides a consistent and precise 5X magnification, regardless of its spacing from a camera or eyepiece. A standard Barlow's magnification can vary with distance, making it less predictable for imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Explore Scientific 5X Focal Extender work with my 2\" eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This model of the Explore Scientific 5X Focal Extender is designed with a \u003cstrong\u003e1.25\" barrel\u003c\/strong\u003e and is only compatible with 1.25\" eyepieces and accessories. It will not fit into a 2\" focuser without an adapter, and it cannot accept 2\" eyepieces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Explore Scientific 5X Focal Extender perform for imaging Jupiter with my 8\" f\/10 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn 8\" f\/10 SCT has a focal length of around 2000mm. The Explore Scientific 5X Focal Extender will increase this to an effective focal length of 10,000mm (f\/50). This very long focal length is excellent for achieving a large image scale on Jupiter with a planetary camera, allowing you to capture fine details in its cloud bands and the Great Red Spot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI wear glasses. How does the Explore Scientific 5X Focal Extender help with high-magnification viewing of the Moon?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Explore Scientific 5X Focal Extender allows you to use a low-power eyepiece, which typically has long and comfortable eye relief, to achieve high magnification. For example, you can use a 32mm Plössl (which you can easily use with glasses on) to get the power of a 6.4mm eyepiece, making detailed lunar observation comfortable without needing to remove your glasses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Explore Scientific 5X Focal Extender reduce the field of view?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Any device that increases magnification will inherently reduce the true field of view by the same factor. When using the Explore Scientific 5X Focal Extender, the patch of sky you see will be 5 times smaller, but the objects within it will appear 5 times larger.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs a 5X magnification increase from the Explore Scientific Focal Extender too much for my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 5X increase is substantial and may exceed the practical magnification limit of your telescope, especially on nights with poor atmospheric seeing. It is best suited for bright targets like the Moon and planets in telescopes with excellent optics and stable seeing conditions. For smaller telescopes or nights of average seeing, a 2X or 3X focal extender may provide more consistently sharp views.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification Factor\u003c\/td\u003e\n\u003ctd\u003e5X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e812257010387\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\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\"\u003eExplore Scientific 5X Focal Extender - 1.25\"\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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific USA One Year\/Limited Extended Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198523677,"sku":"ES-FE05-125","price":181.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-1-25-inch-5X-Focal-Extender-FE05-125-1__66175.1594240337.1280.1280.jpg?v=1684338804"},{"product_id":"explore-scientific-2x-focal-extender-2","title":"Explore Scientific 2X Focal Extender - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2X Focal Extender\u003c\/li\u003e\n\u003cli\u003e2-inch Barrel with 1.25-inch Adapter\u003c\/li\u003e\n\u003cli\u003eTelecentric Optical Design\u003c\/li\u003e\n\u003cli\u003eFully EMD-Coated Optics\u003c\/li\u003e\n\u003cli\u003eEdge-Blackened Lens Elements\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\u003eExplore Scientific 2X Focal Extender - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 2X Focal Extender doubles the power of your entire eyepiece collection, accepting both 1.25-inch and 2-inch formats for maximum compatibility. Its telecentric optical design delivers a consistent 2X magnification factor, unlike a traditional Barlow lens, ensuring predictable, high-contrast views for both visual astronomy and astrophotography.\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\u003e2X Power for All Your Eyepieces: 1.25\" and 2\" Compatibility\u003c\/h3\u003e\n\u003cp\u003eThis 2-inch focal extender instantly doubles the utility of your eyepiece case. By providing 2X magnification, it allows a set of three eyepieces to deliver six different powers, filling gaps in your magnification range without the cost of new eyepieces. Its versatile design accepts both 2-inch and 1.25-inch eyepieces, ensuring it works with every eyepiece you own, from wide-field sweepers to high-power planetary models.\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 True 2X Telecentric Design for Superior Contrast\u003c\/h3\u003e\n\u003cp\u003eUnlike a standard Barlow lens whose magnification can change with distance, the Explore Scientific 2X Focal Extender uses a multi-element telecentric design. This advanced optical system ensures light rays remain parallel to the optical axis, delivering a fixed, true-to-spec 2X magnification regardless of eyepiece or camera spacing. To maximize image fidelity, all air-to-air lens surfaces are fully EMD-coated and all lens elements are edge-blackened, which together suppress internal reflections and produce a darker background sky with superior contrast.\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\u003eMaintain Comfortable Eye Relief at 2X Magnification\u003c\/h3\u003e\n\u003cp\u003eOne of the greatest advantages of a focal extender is its ability to preserve the comfortable eye relief of your low-power eyepieces. When you use this 2X extender with a long eye relief 30mm or 40mm eyepiece, you get the benefit of high magnification without the tight, uncomfortable eye placement typical of short focal length eyepieces. This is a significant advantage for eyeglass wearers and for anyone conducting long, relaxed observing sessions at high power.\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\"\u003eHow is the Explore Scientific 2X Focal Extender different from a standard 2X Barlow lens?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe key difference is its \u003cstrong\u003etelecentric optical design\u003c\/strong\u003e. A traditional Barlow's magnification changes depending on its distance from the eyepiece or camera sensor. The Explore Scientific Focal Extender delivers a constant, true 2X magnification factor, providing more consistent and predictable results for both visual use and imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use my 1.25\" eyepieces with this 2-inch Explore Scientific Focal Extender?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Explore Scientific 2X Focal Extender is designed to be versatile and accepts both 2-inch and 1.25-inch eyepieces and accessories. This allows you to double the magnification of your entire eyepiece collection with a single device.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Explore Scientific 2X Focal Extender help me see more detail on Jupiter with my 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. Using the 2X Focal Extender with a low-to-mid power eyepiece in your 8\" Schmidt-Cassegrain will double the magnification, making it easier to resolve fine details like cloud bands on Jupiter, the Cassini Division in Saturn's rings, and small craterlets on the Moon. It allows you to reach the ideal planetary magnification while using an eyepiece with more comfortable eye relief.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this 2X Focal Extender preserve the eye relief of my eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, and this is one of its primary benefits. When you use the Explore Scientific 2X Focal Extender, you retain the generous eye relief of the eyepiece it's paired with. This lets you enjoy high-power views without the eyestrain or \"squinting\" associated with short focal length eyepieces, a feature especially valuable for observers who wear glasses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 2X Focal Extender suitable for astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The telecentric design is ideal for imaging because it provides a consistent magnification factor and a flatter field than many standard Barlows. It's an excellent choice for increasing your image scale for planetary, lunar, and solar imaging with the appropriate filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will this extender perform with a 24mm 82-degree eyepiece in my 10\" f\/4.7 Dobsonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn this setup, the Explore Scientific 2X Focal Extender will effectively turn your 24mm eyepiece into a 12mm eyepiece, doubling the magnification for high-power views of globular clusters like M13 or planetary nebulae like the Ring Nebula (M57). You get the power of a 12mm eyepiece while enjoying the comfortable eye relief and immersive feel of your 24mm 82-degree eyepiece.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e8122570104000\u003c\/td\u003e\n\u003c\/tr\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\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198589213,"sku":"ES-FE02-020","price":251.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-2-inch-2X-Focal-Extender-FE02-020-FE02-020-1__73557.1594240337.1280.1280.jpg?v=1684338671"},{"product_id":"explore-scientific-3x-focal-extender-2","title":"Explore Scientific 3X Focal Extender - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eProvides 3X magnification for any 2\" or 1.25\" eyepiece\u003c\/li\u003e\n\u003cli\u003eTelecentric optical design ensures consistent magnification\u003c\/li\u003e\n\u003cli\u003eFully EMD-coated optics for maximum light transmission\u003c\/li\u003e\n\u003cli\u003eEdge-blackened lens elements enhance image contrast\u003c\/li\u003e\n\u003cli\u003ePreserves the original eye relief of your 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\u003eExplore Scientific 3X Focal Extender - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 3X Focal Extender triples your eyepiece collection's magnification options, accepting both 2-inch and 1.25-inch eyepiece formats. Its telecentric optical design delivers a true 3X power factor that remains constant regardless of spacing, a critical advantage over traditional Barlow lenses for both visual observation and astrophotography.\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\u003eTriple Your Eyepiece Collection with 3X Power\u003c\/h3\u003e\n\u003cp\u003eThis 3X Focal Extender instantly expands the utility of your existing eyepieces. By placing it in your telescope's 2-inch focuser, you effectively give every eyepiece you own a second, higher-magnification version. An accessory case with three eyepieces now yields six distinct magnification choices, providing greater flexibility for targeting planets, double stars, and small deep-sky objects without needing to purchase a full new set of high-power eyepieces.\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\u003eTelecentric Design: A True 3X Magnification Factor\u003c\/h3\u003e\n\u003cp\u003eUnlike a standard Barlow, the Explore Scientific Focal Extender uses a telecentric design. This multi-element system ensures light rays exit the extender parallel to the optical axis, which produces a fixed, true-to-spec magnification factor. Whether you're using it for visual work or attaching a camera, the 3X power remains consistent, eliminating the variability that can occur with Barlows when eyepiece or camera spacing is altered.\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\u003eHigh-Contrast Views for 2\" Eyepieces \u0026amp; Preserved Eye Relief\u003c\/h3\u003e\n\u003cp\u003eOptical quality is maintained through Enhanced Multilayer Deposition (EMD) coatings on all air-to-glass surfaces and edge-blackened lens elements. This combination maximizes light throughput while suppressing internal reflections, resulting in superior image contrast. A significant ergonomic advantage is that the extender preserves the native eye relief of the eyepiece in use, allowing you to enjoy the comfortable, long eye relief of a low-power eyepiece even at high magnifications—a crucial benefit for eyeglass wearers.\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\u003eFocal Extender vs. Barlow: Why a 3X Telecentric Matters\u003c\/h3\u003e\n\u003cp\u003eWhile a traditional Barlow lens may be lighter or less expensive, its simple design introduces optical trade-offs. The telecentric focal extender is engineered for more demanding applications where optical consistency is paramount.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsistent Magnification:\u003c\/strong\u003e A Barlow's magnification changes with distance from the eyepiece. The 3X Focal Extender's telecentric design locks the magnification at 3X, which is critical for repeatable imaging setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaintained Image Quality:\u003c\/strong\u003e Telecentric extenders are better corrected for field curvature, keeping stars sharp across a wider field of view, especially in fast telescopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallel Light Path:\u003c\/strong\u003e The parallel light rays exiting the extender are less demanding on complex eyepieces and are ideal for use with narrowband H-alpha filters, like those used for solar observing, which require a parallel beam of light for optimal function.\u003c\/li\u003e\n\u003c\/ul\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 is the main difference between the Explore Scientific 3X Focal Extender and a standard 3X Barlow lens?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary difference is the \u003cstrong\u003etelecentric optical design\u003c\/strong\u003e. This ensures the Explore Scientific 3X Focal Extender delivers a consistent 3X magnification regardless of its distance from the eyepiece or camera sensor. A standard Barlow's magnification can vary with spacing, making the focal extender a more precise tool for astrophotography and critical visual observation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 2\" focal extender work with my 1.25\" eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Explore Scientific 3X Focal Extender is designed to accept both 2-inch and 1.25-inch eyepieces. It includes an adapter to securely hold your 1.25-inch accessories, making it a versatile addition to any setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes using the 3X Focal Extender affect the eye relief of my eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, and this is a major advantage. The focal extender is designed to \u003cstrong\u003epreserve the original eye relief\u003c\/strong\u003e of the eyepiece you use with it. This means you can enjoy the comfortable, long eye relief of a low-power eyepiece while observing at 3X the magnification, which is especially beneficial for eyeglass wearers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the 3X Focal Extender perform for imaging Jupiter with my 8\" f\/10 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt's an excellent choice for this scenario. An 8\" f\/10 SCT has a focal length of around 2000mm. The 3X Focal Extender will triple this to an effective focal length of 6000mm (f\/30). This provides the high image scale necessary to resolve fine details in Jupiter's cloud bands, such as the Great Red Spot (GRS) and smaller atmospheric storms, with a planetary camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI want to see more detail in the Orion Nebula (M42) with my 100mm f\/7 refractor. Is this 3X extender the right tool?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt depends on your goal. For resolving the Trapezium cluster at the heart of M42, the 3X extender is perfect. However, the Orion Nebula is a large object, and tripling your magnification will significantly narrow your field of view, potentially cropping out the nebula's faint outer structures. For wide, expansive views of large nebulae, using a low-power eyepiece without the extender is usually preferred.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 2\" Focal Extender heavy enough to cause balance issues?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 2-inch, multi-element accessory like this focal extender is substantially built and will add weight to the back of your telescope. It is always good practice to re-check your telescope's balance on its mount after inserting or removing heavy accessories to ensure smooth tracking and prevent strain on the motors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e8122570185672\u003c\/td\u003e\n\u003c\/tr\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\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198621981,"sku":"ES-FE03-020","price":251.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-2-inch-3X-Focal-Extender-FE03-020-FE03-020-1__19065.1594240337.1280.1280.jpg?v=1684338676"},{"product_id":"explore-scientific-99-reflective-diagonal-2","title":"Explore Scientific 99% Reflective Diagonal -2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2-inch Diagonal Barrel with Tapered Safety Edge\u003c\/li\u003e\n\u003cli\u003e99% Reflectivity from Dielectric Coatings\u003c\/li\u003e\n\u003cli\u003eIncludes 1.25-inch Eyepiece Adapter\u003c\/li\u003e\n\u003cli\u003eNon-Marring Brass Compression Rings\u003c\/li\u003e\n\u003cli\u003eProtects Telescope Optics with Included Dust Covers\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\u003eExplore Scientific 99% Reflective Diagonal - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 99% Reflective Diagonal directs light from your 2-inch focuser to your eyepiece with minimal loss, using advanced dielectric coatings to achieve 99% reflectivity. This package includes a 1.25-inch adapter, allowing you to use eyepieces of both standard barrel sizes while maintaining a bright, high-contrast image path for your refractor or catadioptric telescope.\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\u003e99% Dielectric Coatings for Maximum Brightness\u003c\/h3\u003e\n\u003cp\u003eA standard diagonal mirror can lose between 5% and 12% of the light gathered by your telescope, dimming faint details on planets and deep-sky objects. The Explore Scientific diagonal uses multi-layer dielectric coatings on its first-surface mirror to reflect 99% of incoming light, preserving the brightness and contrast your main optics deliver. This difference is immediately noticeable on faint galaxies or the subtle cloud bands of Jupiter.\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\u003eSecure 2\" and 1.25\" Connections: Compression Rings \u0026amp; Tapered Barrel\u003c\/h3\u003e\n\u003cp\u003eThis diagonal's mechanical design protects both your equipment and your views. Brass compression rings on both the 2-inch holder and the 1.25-inch adapter gently clamp your eyepieces without marring their barrels, ensuring a secure and centered fit. The 2-inch insert barrel features a double taper, which prevents the diagonal from falling out of the focuser if a set screw accidentally loosens.\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\u003eWhy a 99% Dielectric Diagonal Matters vs. Standard Aluminum\u003c\/h3\u003e\n\u003cp\u003eWhile a standard enhanced aluminum diagonal offers around 95% reflectivity when new, its coatings are soft and degrade over time with exposure and cleaning. Dielectric coatings are far more durable—almost as hard as the glass itself—ensuring the 99% reflectivity lasts for the life of the diagonal. For visual observers chasing the faintest details, that extra few percent of light can be the difference between seeing a spiral arm in a galaxy and missing it entirely.\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 is the main advantage of the Explore Scientific 99% Reflective Diagonal over a standard one?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is \u003cstrong\u003elight transmission\u003c\/strong\u003e. The Explore Scientific diagonal's dielectric coatings reflect 99% of light, compared to 88-95% for standard aluminum or silver diagonals. This results in a visibly brighter image, which is critical for observing faint deep-sky objects. These coatings are also far more durable and resistant to aging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I notice a difference with the Explore Scientific 99% diagonal on faint objects like the Veil Nebula (NGC 6960) in my SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. On faint, extended objects like the Veil Nebula (NGC 6960) or the Horsehead Nebula (Barnard 33), maximizing light throughput is essential. The jump from a standard 90% diagonal to this 99% model provides a noticeable boost in contrast and brightness, especially when using nebula filters like an O-III or H-beta.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the compression ring on the Explore Scientific 2\" diagonal protect my eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eInstead of a single set screw that digs into the eyepiece barrel, a \u003cstrong\u003ebrass compression ring\u003c\/strong\u003e provides a firm, even grip around the entire circumference. This prevents the ugly scratches and gouges that set screws can cause, preserving the value and finish of your expensive 2-inch and 1.25-inch eyepieces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Explore Scientific 99% diagonal with my 1.25-inch eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The diagonal comes with a \u003cstrong\u003e1.25-inch adapter\u003c\/strong\u003e that fits securely into the 2-inch eyepiece holder. This adapter also uses a brass compression ring, so your 1.25-inch eyepieces receive the same non-marring protection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI use a refractor for planetary observing. Does a 99% reflective diagonal offer any benefit for Jupiter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile planets like Jupiter are bright, a 99% reflective diagonal still provides a significant benefit. By minimizing light scatter and maximizing transmission, it improves image contrast, making it easier to resolve fine details like small ovals in the cloud belts, subtle colors in the Great Red Spot, and the faint crepe ring of Saturn.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes a dielectric diagonal like the Explore Scientific 2\" model introduce any color error?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. High-quality, multi-layer dielectric mirror coatings are designed to be color-neutral across the entire visual spectrum. Unlike some less expensive diagonals, the Explore Scientific 99% diagonal will not introduce any false color or tint to the image, ensuring the view remains as pure as your telescope's objective lens can deliver.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e2 Inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReflectivity\u003c\/td\u003e\n\u003ctd\u003e99%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoating Type\u003c\/td\u003e\n\u003ctd\u003eDielectric\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEyepiece Adapter\u003c\/td\u003e\n\u003ctd\u003e1.25\" Included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEyepiece Holder\u003c\/td\u003e\n\u003ctd\u003eBrass Compression Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e812257010264\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\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\"\u003eExplore Scientific 2\" Dielectric Diagonal\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e1.25\" Eyepiece Adapter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDust Cover (Telescope Side)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDust Cover (Eyepiece Side)\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\u003cli\u003e\n\u003cp\u003eThis accessory does not require specific drivers or manuals for operation.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198884125,"sku":"ES-DD02-00CF","price":307.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-99-Reflective-2-inch-Diagonal-DD02-00CF-1__77122.1594240339.1280.1280.jpg?v=1684338697"},{"product_id":"explore-scientific-99-reflective-diagonal-3","title":"Explore Scientific 99% Reflective Diagonal -3\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e3-inch diagonal body for large format focusers\u003c\/li\u003e\n\u003cli\u003e99% reflectivity from durable dielectric coatings\u003c\/li\u003e\n\u003cli\u003eIncludes a 2-inch eyepiece adapter with compression ring\u003c\/li\u003e\n\u003cli\u003eDouble-tapered barrel prevents accidental falls\u003c\/li\u003e\n\u003cli\u003eSolid, lightweight construction\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\u003eExplore Scientific 99% Reflective Diagonal - 3\"\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 3-inch Dielectric Diagonal uses a first-surface mirror with a 99% reflective coating to deliver the brightest possible image from your telescope's focal plane to the eyepiece. Designed for telescopes with large 3-inch focusers, this diagonal includes a 2-inch adapter, ensuring it can securely hold the most common large-format eyepieces and imaging accessories.\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\u003e99% Dielectric Coating: Maximizing Light Throughput to Your Eyepiece\u003c\/h3\u003e\n\u003cp\u003eA diagonal's primary job is to preserve the light collected by your telescope's main optic. The multi-layer dielectric coating on this mirror reflects 99% of incoming light, a noticeable improvement over standard aluminum or even enhanced aluminum coatings. This increase in brightness is especially critical when observing faint deep-sky objects like the Veil Nebula (NGC 6960) or distant galaxies where every photon counts.\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\u003eSecure Mechanical Design: 3-Inch Body with Compression Rings and a Safety Taper\u003c\/h3\u003e\n\u003cp\u003eThis diagonal is built for both stability and safety. Eyepieces are held in place by a brass compression ring on the included 2-inch adapter, which prevents the marring and scratching caused by simple set screws. The 3-inch insert barrel features a double taper, a crucial safety feature that prevents the diagonal from slipping out of the focuser if the locking screw becomes loose.\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\u003e3-Inch vs. 2-Inch Diagonals: Why the Larger Format Matters\u003c\/h3\u003e\n\u003cp\u003eWhile a 2-inch diagonal is sufficient for most visual astronomy, a 3-inch model is essential for preventing vignetting in specific applications. Large refractor telescopes and astrographs with 3-inch or larger focusers can illuminate a very wide field, and a 3-inch diagonal ensures that the light cone is not cut off before it reaches a full-frame imaging sensor or an extreme wide-field 2-inch eyepiece.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFor Imagers:\u003c\/strong\u003e If you are using a large-format CMOS or CCD camera, a 3-inch diagonal provides a larger clear aperture to fully illuminate the sensor and avoid darkened corners in your images.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFor Visual Observers:\u003c\/strong\u003e While not always necessary, it provides peace of mind that your widest 2-inch eyepieces are operating without any restriction from the diagonal itself.\u003c\/li\u003e\n\u003c\/ul\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 is the main benefit of the Explore Scientific 3-inch Diagonal's 99% reflectivity?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e99% reflectivity\u003c\/strong\u003e from its dielectric coating ensures maximum light transmission from your telescope to your eyepiece. This results in brighter images, which is especially important for viewing faint deep-sky objects like nebulae and galaxies, compared to standard diagonals which may only reflect 90-96% of the light.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Explore Scientific 3-inch Diagonal fit my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis diagonal is designed specifically for telescopes equipped with a \u003cstrong\u003e3-inch focuser\u003c\/strong\u003e. It will not fit standard 1.25-inch or 2-inch focusers. It is most commonly used with large apochromatic refractors and Ritchey-Chrétien telescopes designed for wide-field imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy would I need a 3-inch diagonal instead of a 2-inch for my large refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor a large refractor with a 3-inch or larger focuser, a 3-inch diagonal is critical for preventing \u003cstrong\u003evignetting\u003c\/strong\u003e (darkening at the edges of the field of view). This is most apparent when using full-frame imaging sensors or very long focal length, wide-field 2-inch eyepieces that utilize the entire light cone produced by the telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Explore Scientific 3-inch diagonal prevent damaging my eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe included 2-inch adapter uses a \u003cstrong\u003ebrass compression ring\u003c\/strong\u003e to secure eyepieces. When you tighten the lock screw, the ring gently and evenly tightens around the eyepiece barrel. This provides a more secure grip than a single set screw and prevents the screw from digging into and scratching the barrel of your expensive eyepieces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI'm imaging the Andromeda Galaxy (M31) with a full-frame sensor; will this 3-inch diagonal help?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Imaging a large target like the Andromeda Galaxy (M31) with a full-frame sensor is exactly the scenario where a 3-inch diagonal is most beneficial. It ensures the entire sensor is evenly illuminated by your telescope's light cone, preventing the vignetting that a smaller 2-inch diagonal would likely cause at the corners of your image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Explore Scientific 3-inch diagonal include an adapter for 1.25\" eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this diagonal comes standard with a \u003cstrong\u003e2-inch adapter only\u003c\/strong\u003e. A separate 2-inch to 1.25-inch adapter would be required to use 1.25-inch eyepieces, though this is not a typical use case for a diagonal of this size.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e812257014774\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e3-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReflectivity\u003c\/td\u003e\n\u003ctd\u003e99% Dielectric\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Adapter\u003c\/td\u003e\n\u003ctd\u003e2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThis product's \"What's in the Box\" information is currently unavailable.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThis product's manuals and software are not available for download at this time.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":44967198916893,"sku":"ES-DD03-01CF","price":825.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Explore-Scientific-99-Reflective-3-inch-Diagonal-DD03-01CF-1__40342.1594240339.1280.1280.jpg?v=1684338701"},{"product_id":"explore-scientific-es-binov","title":"Explore Scientific BinoViewer for Telescopes","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eEngage both eyes for more comfortable, immersive viewing\u003c\/li\u003e\n\u003cli\u003eIntegrated erecting prism provides correctly oriented images\u003c\/li\u003e\n\u003cli\u003eAccepts two matched 1.25\" eyepieces (not included)\u003c\/li\u003e\n\u003cli\u003eIndividual diopter focus for one eye\u003c\/li\u003e\n\u003cli\u003eParfocal design minimizes refocusing when switching from a single 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\u003eExplore Scientific BinoViewer for Telescopes\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific BinoViewer for Telescopes converts your instrument into a two-eyed viewing system, accepting a matched pair of 1.25-inch eyepieces to deliver a more natural and detailed visual experience. It features a diopter adjustment for one eye to achieve a perfectly merged focus for both, while the integrated erecting prism system provides a fully corrected image, making it ideal for both celestial and terrestrial observation.\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\u003eThe Two-Eyed Advantage: Engaging Both Eyes for Enhanced Detail\u003c\/h3\u003e\n\u003cp\u003eViewing with a single eye can cause strain and fatigue during long observing sessions. By engaging both eyes, the Explore Scientific BinoViewer provides a more relaxed and immersive view. Your brain combines the input from both eyes, often resulting in a perceived increase in contrast and the ability to discern finer, lower-contrast details on planets and in deep-sky objects.\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\u003eIntegrated Erecting Prism: Correct-Image Views for Astronomy and Terrestrial Use\u003c\/h3\u003e\n\u003cp\u003eUnlike standard star diagonals that produce a mirror-reversed image, this BinoViewer includes an erecting prism system. This corrects the view to be both right-side-up and non-reversed, exactly as you see with your naked eye or through binoculars. This makes navigating star fields more intuitive and transforms your astronomical telescope into a high-power terrestrial scope for daytime nature observation.\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\u003eCustom-Fit Ergonomics: IPD, Diopter, and Twist-Lock Adjustments\u003c\/h3\u003e\n\u003cp\u003eThe BinoViewer is designed for a comfortable, custom fit. The sliding interpupillary distance (IPD) adjustment allows you to perfectly match the spacing of the eyepieces to your eyes. A helical diopter on one eyepiece holder lets you compensate for differences in your vision, ensuring a sharp, single image. Secure twist-locks on both holders grip your 1.25\" eyepieces firmly without marring their barrels.\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\u003eParfocal by Design: Seamless Switching from a Single 1.25\" Eyepiece\u003c\/h3\u003e\n\u003cp\u003eEngineered to be parfocal, this BinoViewer allows you to locate and center an object with a standard 1.25\" eyepiece, then swap to the binoviewer with minimal refocusing required. This convenience is critical for tracking moving targets or quickly comparing views. While it has been tested to work on a wide range of refractors, reflectors, and SCTs, some fast optical systems may require a Barlow lens (not included) to extend the focus point sufficiently to achieve a sharp image.\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 do I need to use the Explore Scientific BinoViewer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou will need \u003cstrong\u003etwo identical (matched) 1.25\" eyepieces\u003c\/strong\u003e, which are not included. Using identical eyepieces is crucial for your brain to merge the two images into a single, comfortable 3D-like view. For some telescopes, particularly fast Newtonians, you may also need a Barlow lens or optical corrector to reach focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the BinoViewer perform on the Moon with an 8\" Schmidt-Cassegrain?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt performs exceptionally well. An SCT is a great platform for a binoviewer. The two-eyed view enhances subtle contrast along the terminator and inside crater walls, making the lunar surface appear almost three-dimensional. The erecting prism also presents the Moon in its correct orientation, not flipped or mirrored.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the \"erecting prism\" in the BinoViewer do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe erecting prism corrects the image orientation. Telescopes naturally produce an inverted and\/or mirror-reversed image. This prism system flips the image so that it is \u003cstrong\u003eright-side-up and laterally correct\u003c\/strong\u003e, just like you would see with a pair of binoculars. This is excellent for terrestrial viewing and makes navigating the sky more intuitive.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific BinoViewer difficult to focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it's designed for ease of use. First, achieve focus with your right eye using the telescope's main focuser. Then, close your right eye and use the BinoViewer's helical diopter adjustment to bring the left-eye view into sharp focus. Once set, both eyes will see a single, crisp image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the BinoViewer for birdwatching with my 80mm refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The integrated erecting prism makes it a perfect choice for terrestrial observation. With a pair of low-to-medium power eyepieces, your refractor becomes a high-magnification spotting scope, and the two-eyed view is far more comfortable for extended periods of birdwatching than using a single eyepiece.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this BinoViewer work with my Newtonian reflector telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt may, but Newtonian reflectors often have limited back-focus. Because a binoviewer adds a long light path, you may need to use a \u003cstrong\u003eBarlow lens\u003c\/strong\u003e in the focuser before the binoviewer. The Barlow pushes the focal point outwards, allowing the binoviewer to reach focus. Compatibility depends on your specific telescope's design.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e0811803034280\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Explore_Scientific_ES-BINOV_BinoViewer_for_Telescopes_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBinoViewer for Telescopes\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\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Explore_Scientific_ES-BINOV_BinoViewer_for_Telescopes_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":52909381746973,"sku":"ES-BINOV","price":700.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-BinoViewer-for-Telescopes-1_6436baa0-1c97-48e8-8fd0-c525d94277aa.jpg?v=1789061527"}],"url":"https:\/\/davidastro.com\/collections\/explore-scientific-visual-accessories.oembed","provider":"David Astro","version":"1.0","type":"link"}