{"title":"Explore Scientific Focal Extenders","description":"\u003cp\u003eExplore Scientific Focal Extenders multiply the focal length of your telescope to raise magnification, using a telecentric design rather than a simple Barlow layout. They come in 2x and 3x for both 1.25\" and 2\" eyepieces, plus a 5x in 1.25\".\u003c\/p\u003e\u003cp\u003eA telecentric extender keeps eye relief and field illumination close to the eyepiece's native behavior, which helps with wide-field eyepieces. The 3x and 5x models suit planetary imaging and high-power views of the Moon, planets and double stars.\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"}],"url":"https:\/\/davidastro.com\/collections\/explore-scientific-focal-extenders.oembed","provider":"David Astro","version":"1.0","type":"link"}