{"product_id":"sky-rover-2-amici-prism-erect-image-diagonal","title":"Sky Rover 2\" Amici Prism Erect-Image Diagonal","description":"\u003cp\u003eA regular star diagonal makes a refractor comfortable to look through, but it leaves the image mirror-reversed. For astronomy that is usually harmless. For daytime viewing, lunar observing, outreach, or anyone trying to match the eyepiece to a chart, it can be surprisingly awkward.\u003c\/p\u003e\n\n\u003cp\u003eThe Sky Rover 2\" Amici Prism Diagonal gives you the same comfortable 90° viewing position with a correct-image view: upright and correct left to right. A bird moves the direction you expect. Writing reads normally. Lunar features appear where you expect to find them. And when you sweep the sky with a chart beside you, you no longer have to reverse the map in your head.\u003c\/p\u003e\n\n\u003cp\u003eWhat makes this version especially interesting is that Sky Rover built it as a full 2-inch diagonal. The Amici roof prism uses H-K9L optical glass, a 46mm clear entrance aperture, and XMC ultra-wideband multi-layer coatings, giving wide-field 2-inch eyepieces room to do what you bought them to do.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Use a Correct-Image Diagonal?\u003c\/h3\u003e\n\n\u003cp\u003eA standard mirror diagonal reflects the light once. The resulting image is upright, but left and right are reversed. Most astronomers get used to it quickly, but there are times when a natural view simply makes more sense.\u003c\/p\u003e\n\n\u003cp\u003eAn Amici roof prism adds the additional image correction needed to restore normal orientation. Look through the Sky Rover and the scene appears the same way it does to your unaided eye: upright and correct from left to right.\u003c\/p\u003e\n\n\u003cp\u003eThat makes the difference immediately obvious in daylight. Point a refractor toward birds, wildlife, distant terrain, boats, aircraft, or a target at the range and you can follow movement naturally instead of compensating for a mirror-reversed view.\u003c\/p\u003e\n\n\u003cp\u003eAt night, the same orientation can make star-hopping, lunar observing, and public outreach more intuitive. A chart or lunar atlas is easier to compare with what you see in the eyepiece, and first-time observers do not have to learn a reversed view before they can enjoy the telescope.\u003c\/p\u003e\n\n\u003ch3\u003eA Full 2-Inch Optical Path\u003c\/h3\u003e\n\n\u003cp\u003eMany correct-image accessories are built around 1.25-inch optics and modest fields of view. Sky Rover went larger.\u003c\/p\u003e\n\n\u003cp\u003eThe Amici prism has a 46mm clear entrance aperture, putting it in the range needed for genuinely wide 2-inch eyepieces. Pair it with a long-focal-length wide-field eyepiece and a short refractor becomes an impressive instrument for scanning landscapes by day or cruising large star fields after dark.\u003c\/p\u003e\n\n\u003cp\u003eThe prism itself is made from H-K9L optical glass and uses Sky Rover's XMC ultra-wideband multi-layer coating to maintain good transmission and contrast through the additional glass path.\u003c\/p\u003e\n\n\u003cp\u003eThe body uses a standard 2-inch telescope barrel and 2-inch eyepiece connection, so it fits refractors equipped for standard 2-inch astronomical accessories.\u003c\/p\u003e\n\n\u003ch3\u003eOne Refractor, Two Very Different Jobs\u003c\/h3\u003e\n\n\u003cp\u003eA good astronomical refractor can be a remarkably good terrestrial telescope. Unlike a conventional spotting scope, you are not locked into one eyepiece or one magnification range. Choose a low-power 2-inch eyepiece when you want a broad field, then change eyepieces when you want a closer look.\u003c\/p\u003e\n\n\u003cp\u003eThe Amici prism supplies the part an astronomical refractor normally lacks: a naturally oriented view.\u003c\/p\u003e\n\n\u003cp\u003eThat makes a portable 70mm, 80mm, or 100mm refractor equally at home looking across a lake in the afternoon and sweeping through Cygnus after sunset. Larger refractors can do the same thing when portability is less important.\u003c\/p\u003e\n\n\u003cp\u003eThe 90° viewing angle is also much more comfortable than looking straight through the back of a refractor, particularly when the telescope is aimed horizontally or slightly upward for long observing sessions.\u003c\/p\u003e\n\n\u003ch3\u003eUnder the Night Sky\u003c\/h3\u003e\n\n\u003cp\u003eThe correct-image view is not only a daytime feature.\u003c\/p\u003e\n\n\u003cp\u003eWith a low-power 2-inch eyepiece, an Amici diagonal makes wide-field observing feel unusually natural. Sweep the Milky Way through Cygnus, Sagittarius, or Cassiopeia. Frame the Pleiades, Double Cluster, or large open clusters. Explore the Moon while comparing the view directly with an atlas.\u003c\/p\u003e\n\n\u003cp\u003eIt can also be particularly useful for outreach. Someone looking through a telescope for the first time does not have to be told that everything is reversed. The Moon appears in a familiar orientation, and moving the telescope toward something behaves the way a new observer expects.\u003c\/p\u003e\n\n\u003cp\u003eAn Amici prism does have a tradeoff. The two roof surfaces meet along a fine edge, and very bright stars or planets positioned near that roof line can sometimes show a faint diffraction line or spike. How visible it is depends on the target, magnification, telescope, and the individual prism.\u003c\/p\u003e\n\n\u003cp\u003eFor critical planetary observing, close double stars, and other work where you want the cleanest possible diffraction pattern, a good dielectric mirror diagonal remains the better tool. The Amici earns its place when correct orientation and a wide natural field matter more.\u003c\/p\u003e\n\n\u003ch3\u003eCommunity Says\u003c\/h3\u003e\n\n\u003cp\u003eThere is not much Sky Rover-specific owner discussion yet, but experienced Cloudy Nights observers using other quality 2-inch Amici diagonals consistently describe the same appeal: terrestrial observing feels natural, charts are easier to follow, and wide-field astronomical sweeping can be especially enjoyable.\u003c\/p\u003e\n\n\u003cblockquote\u003e\n\u003cp\u003e\"It's a fantastic experience to randomly sweep through the Milky-Way star fields at lower powers.\"\u003c\/p\u003e\n\u003cp\u003e— Cloudy Nights member using a 2-inch Amici diagonal with a Tele Vue 85\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\n\u003cp\u003eOther observers report using 2-inch Amici prisms for both daytime and nighttime observing, with some seeing a fine roof-line spike on bright stars and others finding it difficult to notice at the magnifications they normally use. That matches the reason to choose an Amici in the first place: not because it replaces every astronomical diagonal, but because it provides something a conventional mirror cannot — a correctly oriented image.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrect-image view.\u003c\/strong\u003e Upright and correct left to right rather than mirror-reversed.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003e90° viewing angle.\u003c\/strong\u003e Comfortable for both terrestrial observing and astronomical use.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003e46mm clear entrance aperture.\u003c\/strong\u003e Designed to take advantage of wide-field 2-inch eyepieces.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003eH-K9L optical-glass Amici prism.\u003c\/strong\u003e The roof-prism design provides the additional image correction needed for natural orientation.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003eXMC ultra-wideband multi-layer coating.\u003c\/strong\u003e Helps maintain transmission and contrast through the prism optical path.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003eStandard 2-inch telescope connection.\u003c\/strong\u003e Fits refractors and other telescopes using a standard 2-inch accessory connection.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003e2-inch eyepiece capability.\u003c\/strong\u003e Lets you use large-field-stop eyepieces that smaller correct-image diagonals cannot fully accommodate.\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003eAluminum housing.\u003c\/strong\u003e A rigid body keeps the prism securely aligned in the optical path.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFocus Travel\u003c\/h3\u003e\n\n\u003cp\u003eAn Amici prism has a substantial optical path, so it can require more inward focuser travel than some mirror diagonals.\u003c\/p\u003e\n\n\u003cp\u003eMost refractors designed around standard 2-inch accessories should have adequate adjustment, but telescopes that already reach focus very close to the inward limit of the focuser deserve a little more attention. If you are unsure whether a particular telescope and eyepiece combination will reach focus, call us and we can help check the combination.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between an Amici diagonal and a regular star diagonal?\u003c\/strong\u003e\u003cbr\u003e\nA conventional mirror diagonal gives an upright but left-right reversed image. An Amici roof prism corrects that reversal, producing an upright image with natural left-to-right orientation.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy would I want a correct-image view for astronomy?\u003c\/strong\u003e\u003cbr\u003e\nIt makes comparing the eyepiece with star charts or lunar maps more intuitive and can make public observing easier for beginners. Many observers also simply enjoy a naturally oriented view when sweeping large areas of the sky.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIs this mainly for daytime use?\u003c\/strong\u003e\u003cbr\u003e\nNo. Terrestrial observing is one of its most obvious uses, but a 2-inch Amici can also be very enjoyable for low- and moderate-power astronomical observing, lunar viewing, outreach, and wide-field star-hopping.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use it on the planets?\u003c\/strong\u003e\u003cbr\u003e\nYou can, but a conventional mirror diagonal remains the better choice when your priority is the cleanest possible high-power image. The roof edge in an Amici prism can produce a fine diffraction line on very bright objects, especially when they cross the center of the field.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill I see a line through every star?\u003c\/strong\u003e\u003cbr\u003e\nNo. The roof-line effect is most likely to become noticeable on bright stars or planets, and observers report considerable variation in how obvious it is. It is generally much less relevant in terrestrial viewing and low-power wide-field astronomy.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill it work with wide-field 2-inch eyepieces?\u003c\/strong\u003e\u003cbr\u003e\nThat is one of the main reasons for choosing this diagonal. The prism has a 46mm clear entrance aperture, allowing it to take advantage of the large field stops available in the 2-inch eyepiece format.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill it reach focus in my refractor?\u003c\/strong\u003e\u003cbr\u003e\nMost refractors intended for 2-inch accessories should be good candidates, but the Amici prism has a longer optical path than many mirror diagonals and therefore requires additional inward focuser travel. If your telescope already focuses close to its inward limit, check the combination before ordering.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDoes it only work with Sky Rover telescopes?\u003c\/strong\u003e\u003cbr\u003e\nNo. It uses a standard 2-inch connection and can be used with compatible refractors from many manufacturers.\u003c\/p\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eThe reason to buy the Sky Rover 2\" Amici Prism Diagonal is not simply to make a telescope usable in daylight. It is to make the view through a refractor behave naturally without giving up the wide fields that make a 2-inch focuser worthwhile.\u003c\/p\u003e\n\n\u003cp\u003eBy day, birds, wildlife, landscapes, and distant objects appear upright and in the correct left-to-right orientation. At night, star fields and lunar features are easier to relate to charts, and public observing becomes more intuitive for someone looking through a telescope for the first time.\u003c\/p\u003e\n\n\u003cp\u003eA mirror diagonal is still the better choice for critical high-power planetary and double-star observing. But when you want a comfortable 90° view, correct orientation, and the field of a true 2-inch eyepiece, the Amici does something an ordinary star diagonal simply cannot.\u003c\/p\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eType\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e90° erecting prism diagonal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eImage Orientation\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully erect, non-reversed (upright and left-to-right correct)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003ePrism Type\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAmici roof prism\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003ePrism Material\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eH-K9L optical glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eXMC ultra-wideband multi-coating on prism surfaces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eClear Aperture\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e46mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eLight Path (Geometric Length)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eApprox. 135.6mm including 2″ eyepiece holder; adds approx. 9.5mm with the 2″-to-1.25″ adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBarrel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2″ (50.8mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eMechanical Threads\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eTelescope-side 2″ barrel: M50.5 × 1; eyepiece-side 2″ holder: φ51\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eEyepiece Holder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2″, with internal protective stop\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessory\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2″-to-1.25″ adapter (50.8mm to 31.7mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e660 g (23.3 oz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eRecommended Use\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eLow-power terrestrial and astronomical viewing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eManufacturer SKU\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e26757\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Sky Rover","offers":[{"title":"Default Title","offer_id":67638943678537,"sku":null,"price":319.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/1_beb08ddc-d8f6-4102-9e0b-df791a6be1e1_1.webp?v=1791488247","url":"https:\/\/astronomics.com\/products\/sky-rover-2-amici-prism-erect-image-diagonal","provider":"Astronomics","version":"1.0","type":"link"}