{"title":"Pentax","description":"Pentax, well versed in optical systems after over 100 years in lens crafting, produces high quality sport optics and telescope eyepieces.","products":[{"product_id":"3-5mm-xw-extra-wide-angle-eyepiece","title":"Pentax 3.5mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis very short focal length Pentax eyepiece has a wide 70° field of view combined with a long 20mm eye relief for eyeglass use. It's a combination of virtues you won't find in any other eyepiece in its focal length range. It uses eight lenses in five groups to provide outstanding high magnification observing with short focal length refractors and fast focal ratio\/short focal length Dobsonian reflectors. The wide and flat field of view allows longer undisturbed viewing with a Dobsonian. This allows several people to observe before an object has to be recentered in the field, a help for family viewing or star parties. Its long eye relief is particularly helpful if you \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing, although all observers will benefit from its wide field and sharp images. Using it with an 820mm 4\" f\/8 Takahashi FS-102 fluorite refractor, for example, will result in 234x (58x per inch of aperture) and a 0.44mm exit pupil (about 1\/50th of an inch across). Both of these figures are very close to the generally-accepted maximum values of magnification per inch of aperture and exit pupil size for usable observing under \u003cem\u003egood to very good \u003c\/em\u003eseeing conditions for a reasonably experienced observer.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e14.3 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632692297,"sku":"PXW03","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW3-5_b_NEW.png?v=1722974617"},{"product_id":"5mm-xw-extra-wide-angle-eyepiece","title":"Pentax 5mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis short focal length Pentax eyepiece has a very wide 70° field of view and very long 20mm eye relief, a uniquely useful combination not matched by other eyepieces. It uses eight lenses in five groups to provide outstanding medium to medium high magnification astronomical observing with short focal length refractors and fast focal ratio\/short focal length Dobsonian reflectors. Its long eye relief is particularly helpful if you \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing, although all observers will benefit from its wide field and sharp images. It provides about the maximum usable magnification with a typical 8\" or 10\" f\/10 Schmidt-Cassegrain telescope. It has good contrast for seeing subtle lunar and planetary details, and for seeking out small planetary nebulas.\u003c\/p\u003e\n\u003cp\u003eIt will generally be useful with \u003cem\u003elong \u003c\/em\u003efocal length refractors, reflectors, or catadioptric scopes only under \u003cem\u003every good or better \u003c\/em\u003eseeing conditions. \u003cem\u003eAverage \u003c\/em\u003eseeing will limit its usefulness. Using it with a 2000mm 8\" f\/10 Schmidt-Cassegrain, for example, will result in 400x (50x per inch of aperture) and a 0.5mm exit pupil (about 1\/50th of an inch across). Both of these are very close to the generally-accepted maximum values of magnification per inch of aperture and exit pupil size for usable observing under \u003cem\u003egood to very good \u003c\/em\u003eseeing conditions for a reasonably experienced observer.\u003cbr\u003e\n\u003c\/p\u003e\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e14 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632725065,"sku":"PXW05","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/5mm_pentax.jpg?v=1722975505"},{"product_id":"7mm-xw-extra-wide-angle-eyepiece","title":"Pentax 7mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis wide field Pentax eyepiece is designed for high power observing of objects on the ground by day and in the skies at night.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is the most powerful eyepiece usable for nature studies with the 80mm and 100mm Pentax spotting scopes under brightly lit observing conditions.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eit's an excellent choice for high power lunar and planetary observing with long focal length refractors, reflectors, or catadioptric scopes under good to somewhat better than average seeing conditions. It is also exceptional for medium power viewing with short focal length refractors and fast focal ratio Dobsonian reflectors. It has eight lenses in a six group optical design. This gives a sharpness across its very wide 70° field that makes smaller globular clusters vivid and nearly three-dimensional. It is also more or less regularly useful for astronomical observing with long focal length telescopes, but \u003cem\u003ebelow average \u003c\/em\u003eseeing conditions will limit its performance. If \u003cem\u003eso-so \u003c\/em\u003eseeing is the norm where you observe, its 7mm focal length may represent the maximum practical with a long focal length scope.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 71x magnification and a 52' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 74x magnification and a 50' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 90x magnification and a 41' field of view. \u003cbr\u003eIn all cases the spotting scope exit pupil will be in the neighborhood of 1mm, providing somewhat dim images if the scene being observed is not brightly lit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e7mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e52x terrestrially\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e14.3 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632790601,"sku":"PXW07","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/70513__eyepiece_smc_pentax_xw_7.jpg?v=1722975438"},{"product_id":"10mm-xw-extra-wide-angle-eyepiece","title":"Pentax 10mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis short focal length Pentax is a high power eyepiece usable for both terrestrial and astronomical observing.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is superb for detailed long-distance nature studies with the 80mm and 100mm Pentax spotting scopes under average lighting conditions.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eit's an excellent high power lunar and planetary observing eyepiece with long focal length refractors, reflectors, or catadioptric scopes under average seeing conditions. Its 10mm focal length is an ideal match for an f\/10 Schmidt-Cassegrain, providing 200x and a 1mm exit pupil that closely matches the resolution of the scope to that of your eye. Some of the larger globular clusters, such as M13, will fill its 0.35-degree field with such a scope. It is also exceptional for medium power viewing with short focal length refractors and fast focal ratio Dobsonian reflectors. It has seven lenses in a six group optical design for a very wide 70° field. It is regularly useful for astronomical observing with long focal length scopes, but \u003cem\u003ebelow average \u003c\/em\u003eseeing conditions may limit its performance somewhat. If \u003cem\u003eso-so \u003c\/em\u003eseeing is the norm where you observe, its 10mm focal length will often represent the maximum practical with a long focal length scope.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 50x magnification and a 74' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 52x magnification and a 71' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 63x magnification and a 58' field of view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e74'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e10mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e50x terrestrially\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e13.8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632823369,"sku":"PXW10","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW10_b.png?v=1722974046"},{"product_id":"14mm-xw-extra-wide-angle-eyepiece","title":"Pentax 14mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis medium focal length Pentax is a dual-purpose eyepiece for both terrestrial and astronomical observing.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is an excellent moderate power eyepiece for detailed long- and medium-distance nature studies with the 80mm and 100mm Pentax spotting scopes under virtually any lighting conditions, dawn to dusk.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eit provides superb medium power wide field lunar and planetary observing with long focal length refractors, reflectors, or catadioptric scopes. With short focal length refractors and fast focal ratio reflectors, it gives a \"picture window on space\" image. An f\/4.5 Dobsonian reflector, for example, will yield a 3.1mm exit pupil, for bright images of emission nebulas and galaxies. Its sharpness across the field makes smaller globular clusters vivid and nearly three-dimensional. The 650mm focal length TMB-105 triplet apo refractor provides 46x, a 2.25mm exit pupil, and a 1.3-degree field (almost three times as wide as the Moon). These figures are all very usable for observing open clusters such as the Pleiades, large nebulas such as the Lagoon, and large globulars such as M-13. All will fit nicely into the field of view, with a framework of black velvet around them to set off their subtleties.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 36x magnification and a 102' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 37x magnification and a 99' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 45x magnification and an 81' field of view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e102'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e14mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e36x terrestrially\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e12.9 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632856137,"sku":"PXW14","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW14_b.png?v=1722974163"},{"product_id":"20mm-xw-extra-wide-angle-eyepiece","title":"Pentax 20mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis medium focal length Pentax provides sharp and very wide field images for both terrestrial and astronomical observing.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is an excellent medium power wide field eyepiece for detailed close-in or wide field nature studies with the 80mm and 100mm Pentax spotting scopes in overcast and sub-par light conditions, dawn to dusk.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eits six lens\/four group design makes it an excellent high-contrast choice for medium power deep space observing with long focal length refractors, reflectors, or catadioptric scopes. It is a superb low power eyepiece with short focal length refractors and fast focal ratio reflectors. An f\/4.5 Dobsonian reflector, for example, will yield a 4.4mm exit pupil, excellent for detailed images of emission nebulas and galaxies. Its sharpness across the field makes globular clusters and nebulas vivid and nearly three-dimensional. The 650mm focal length TMB-105 triplet apo refractor provides 32.5x, a 4mm exit pupil, and a 2.15-degree field (over four times as wide as the Moon). These figures are all very usable for observing open clusters such as the Pleiades; large nebulas such as the Lagoon, Veil, and Orion; and large globulars such as M-13 and Omega Centauri. All will fit nicely into the field of view, with a generous framework of black velvet sky around them to set off their subtleties.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 25x magnification and a huge 147' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 26x magnification and a 141' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 32x magnification and a big 115' field of view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e147'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e25x terrestrially\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e12.6 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632888905,"sku":"PXW20","price":346.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW20_b.png?v=1722974444"},{"product_id":"30mm-xw-extra-wide-angle-2-eyepiece","title":"Pentax 30mm XW Extra Wide Angle 2\" Eyepiece","description":"\u003cp\u003eThis medium focal length 2\" Pentax eyepiece is an excellent choice for medium power deep space observing with long focal length refractors, reflectors, or catadioptric scopes that have a 2\" focuser or star diagonal. It is a superb low power eyepiece with short focal length refractors and fast focal ratio reflectors. An f\/4.5 Dobsonian reflector, for example, will yield a 6.7mm exit pupil, close to the largest usable for bright images of emission nebulas and galaxies. Its sharpness across the wide 70° field makes open star clusters and large nebulas vivid and nearly three-dimensional. The 650mm focal length TMB-105 triplet apo refractor provides 22x, a 6mm exit pupil, and a 3.2-degree field (almost seven times as wide as the Moon). These figures are all virtually perfect for observing open clusters such as the Pleiades; large nebulas such as the Lagoon, Veil, and Orion; large globulars such as M-13 and Omega Centauri; and large galaxies such as M-31 and M-33. All fit easily into the field of view, with a spacious framework of black velvet sky around them to set off their subtleties.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003eThe substantial 26 oz. weight of the eyepiece may require rebalancing of some Dobsonians if you switch between this 2\" eyepiece and a lighter 1.25\" eyepiece.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e30mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e26.1 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221632954441,"sku":"PXW30","price":496.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW30.png?v=1722974963"},{"product_id":"40mm-xw-extra-wide-angle-2-eyepiece","title":"Pentax 40mm XW Extra Wide Angle 2\" Eyepiece","description":"This long focal length 2\" Pentax eyepiece is outstanding for low power\/wide field astronomical observing with long focal length refractors and catadioptric telescopes . . .\n\u003cp\u003eThis long focal length 2\" Pentax eyepiece is outstanding for low power\/wide field astronomical observing with long focal length refractors and catadioptric telescopes. However, it is not that well suited to fast focal ratio reflectors. For example, it provides a huge 8.9mm exit pupil with an f\/4.5 Dobsonian reflector. As the eyes of most observers are unable to dilate to this size, this eyepiece will probably waste a good portion of the light-gathering capacity of a fast focal ratio scope. It is better suited to longer focal ratio refractors, Schmidt-Cassegrains, and Maksutov-Cassegrains than it is to reflectors with focal ratios shorter than f\/6. Using it with a 2\" star diagonal in a 2000mm 8\" f\/10 Schmidt-Cassegrain, for example, will result in 50x and a wide 1.4° field of view. That is almost three times the diameter of the full Moon and a large enough field to fit in all of the Pleiades, with room to spare. It will also work well for rich field observing with moderately fast focal ratio refractors. For example, with the 600mm focal length TeleVue TV-85 it provides 15x, a 5.7mm exit pupil, and a huge 4.7° field. With the 650mm focal length TMB-105 triplet apo, it provides 16.3x, a 6.45mm exit pupil, and a 4.3° field. On both scopes, the fields are eight to nine times as wide as the Moon. These figures are all very usable for capturing galaxy clusters, viewing emission and reflection nebulas and open star clusters in their entirety, scanning the star clouds of Sagittarius and large and faint nebula remnants such as the Veil, etc. You can use the calculator below to see how wide a field it will give you with your particular scope.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. The substantial 24.7 oz. weight of the eyepiece may require rebalancing of some Dobsonians if you switch between this 2\" eyepiece and a lighter 1.25\" eyepiece.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e40mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e24.7 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221633151049,"sku":"PXW40","price":526.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/XW40.png?v=1722975047"},{"product_id":"8-24mm-smc-1-25-long-eye-relief-astronomical-zoom-21-63x-or-26-78x-spotting-scope-zoom","title":"Pentax 8-24mm SMC 1.25\" Long Eye Relief Astronomical Zoom; 21-63x or 26-78x Spotting Scope Zoom","description":"\u003cp\u003eThis is an ultra-premium six-element zoom eyepiece. It has a long eye relief that's particularly well-suited to those who must wear eyeglasses while observing (such as those with severe astigmatism). It is designed for use with Pentax 80mm and 100mm spotting scopes, but can also be used for astronomical observing in any telescope accepting 1.25\" accessories. One of four grooves at the tip of its 1.25\" chrome barrel engages a steel pin in the eyepiece port of the Pentax spotting scopes. This keeps the eyepiece from rotating when the knurled rubber power change collar on the eyepiece is turned to change magnifications. Be sure that the pin in the scope body is engaged properly with the eyepiece before tightening the locking collar on a Pentax spotting scope.\u003c\/p\u003e\n\u003cp\u003eAll of the lenses in the zoom are fully multicoated with proprietary Pentax SMC (Super MultiCoated) antireflection coatings for high light transmission. They are the same coatings as those used on the most costly Pentax camera lenses. For better contrast, in addition to the inside of the barrel being blackened, the edges of all lenses have also been blackened to eliminate any internal reflections within the lenses themselves. ED (extra low dispersion) glass lens elements are used to minimize chromatic aberrations and astigmatism. The result is very good contrast and center resolution, with very little ghosting. A rubber eyecup twists in and out of eyepiece body to optimize your eye position and shield your eye from ambient light. When the eyecup is fully retracted for eyeglass use, the eye relief ranges from 12mm to 18mm, depending on the focal length selected. This allows observers with eyeglasses to see the entire field of view at low powers, where the eye relief is 18mm, although some vignetting of the field occurs at higher powers. As you generally are looking only at smaller objects that do not fill the field at higher powers, the loss of some of the field edge due to vignetting is not usually a concern. The barrel of the eyepiece in marked in both magnifications with an 80mm Pentax spotting scope and in focal lengths for astronomical observing. An index mark shows the power in use.\u003c\/p\u003e\n\u003cp\u003eAs with any zoom eyepiece, the precise focal length or magnification of the Pentax zoom at any given point in time is not all that important. The experienced observer invariably adjusts the zoom magnification to match the seeing conditions and object size as he looks through the eyepiece, rather than first setting the zoom to an arbitrary focal length value according to the scale on the side of the eyepiece and using it at that power no matter what the seeing conditions. The flexibility of a zoom to instantly match the magnification to changing lighting or seeing conditions is one of the zoom eyepiece's chief advantages. Match that flexibility to Pentax-grade optics and you have an exceptional tool for any observer - terrestrial or astronomical.\u003c\/p\u003e\n\u003cp\u003eFor astronomical use, the zoom is usable for medium to high power observing with telescopes of all optical designs - from long focal ratio refractors down to fast f\/4.5 Dobsonian reflectors. The eyepiece is relatively heavy and physically large, so some care is needed in balancing free-moving astronomical telescopes (such as Dobsonians) when this eyepiece is in use. The eyepiece container listed below is recommended purely as a replacement should the standard plastic container supplied with the eyepiece be lost or damaged.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial use with 80mm aperture, 520mm focal length Pentax spotting scopes . . . \u003c\/strong\u003e\u003cbr\u003eThe zoom at a barrel marking of 20x is actually 21x with a 93' field at 1000 yards and 18mm of usable eye relief. \u003cbr\u003eAt a barrel marking of 40x it is actually 43x with a 60' field and 12mm of usable eye relief. \u003cbr\u003eAt a barrel marking of 60x it is actually 63x with a 49' field and 15mm of usable eye relief.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial use with 100mm aperture, 630mm focal length Pentax spotting scopes . . . \u003c\/strong\u003e\u003cbr\u003eThe zoom at a barrel marking of 20x actually provides 26x, with a 78' field at 1000 yards and 18mm of usable eye relief. \u003cbr\u003eAt a barrel marking of 40x it actually provides 53x, with a 48' field and 12mm of usable eye relief. \u003cbr\u003eAt a barrel marking of 60x it actually provides 78x, with a 39.5' field and 15mm of usable eye relief.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical telescope use in a 1.25\" focuser or star diagonal . . . \u003c\/strong\u003e\u003cbr\u003eThe zoom at a marking of 24mm has a 38 degree apparent field and 18mm of usable eye relief. \u003cbr\u003eAt 16mm (not marked on the barrel, but easily interpolated), it has a 44 degree apparent field and 15mm of usable eye relief. \u003cbr\u003eAt 12mm it has a 49 degree apparent field and 12mm of usable eye relief. \u003cbr\u003eAt 8mm it has a 60 degree apparent field and 15mm of usable eye relief.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e19.2 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221634822217,"sku":"PXLZ","price":359.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/3772_1.jpg?v=1662966728"},{"product_id":"pentax-camera-adapter-for-pentax-k-mount-cameras-only","title":"Pentax Camera adapter (for Pentax K-mount cameras only)","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cstrong\u003eThis Product Has Been Discontinued And Is No Longer For Sale.  This Product Is Listed For Informational Purposes Only.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThis adapter converts a 100mm Pentax spotting scope into a 1250mm telephoto lens, and an 80mm Pentax into a 1000mm telephoto. For Pentax K-mount cameras only . . .The Pentax camera adapter can be used with any Pentax K-mount 35mm camera, or any 35mm single lens reflex (SLR) camera body using the popular Pentax K-mount lens system. It will not work with cameras from Canon, Nikon, Leica, Olympus, etc. It converts the 100mm Pentax spotting scope into a 1250mm f\/12.5 telephoto lens, the 80mm Pentax scopes into a 1000mm f\/12.5 telephoto, and the 65mm Pentax scopes into a 780mm f\/12 telephoto.\u003c\/p\u003e\n\u003cp\u003eUnlike other adapters, the PF-CA35 does not use a light-robbing eyepiece to project the image from the scope to the film plane. Instead, it uses a five-lens, four-group no-eyepiece optical system for flat-field images that rival the resolution of telephoto lenses designed strictly for camera use. All air-to-glass surfaces in the adapter are fully multicoated for high light transmission and contrast. Plastic endcaps keep dust out of the optical system when the adapter is not in use.\u003c\/p\u003e\n\u003cp\u003eThe adapter focuses at the same point as a normal scope eyepiece. This allows you to remove the eyepiece from your scope and quickly replace it with the camera adapter without having to waste time to refocus. The adapter provides a 2° field of view with a 100mm scope, with a 30' close focus. With an 80mm scope, the field is 2.5° and the close focus is 22'. With a 65mm scope, the field is 3.2° and the close focus is 18'.\u003c\/p\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40221675094089,"sku":"PF-CA35","price":419.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19603.jpg?v=1662968067"},{"product_id":"pentax-20-60x-zoom-xf-eyepiece-for-65mm-pentax-spotting-scopes","title":"Pentax 20-60X Zoom XF Eyepiece For 65mm Pentax Spotting Scopes","description":"\u003cp\u003eThis Pentax zoom eyepiece is physically sized for use with the compact 65mm Pentax spotting scopes. It can also be used with the 80mm and 100mm Pentax scopes if the size and weight of the larger XW eyepieces normally used with them becomes an issue with those models. It has a 1.25\" barrel, so it can also be used as a zoom eyepiece with astronomical telescopes accepting 1.25\" eyepieces.\u003c\/p\u003e\n\u003cdiv\u003eIt has a variable focal length range of 19.5mm to 6.5mm. This provides a zoom range of 20x to 60x magnification with the 65mm Pentax scopes, to cover a wide range of birding and nature study situations. Its apparent field of view ranges from 42° at 20x to 60° at 60x. This provides an actual 2.1° field (110' @ 1000 yards) at 20x and a 1° field (52.5' @1000 yards) at 60x. (It provides a magnification range of 26x to 78x with the straight-through 80mm Pentax scope, 27x to 81x with the straight-through 80mm Pentax, and 32.5x to 97.5x with the 100mm Pentax.)\n\u003cp\u003eThe usable eye relief ranges from 14mm at 20x to 10mm at 60x. These somewhat-short figures will vignette the field of view for those who \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing due to astigmatism, particularly at the higher powers. Those who do not wear glasses will find the eye relief more than acceptable for unvignetted viewing, particularly when the rubber-rimmed twist-up eyecup is extended to block out ambient light and position the eye at the correct eyepoint.\u003c\/p\u003e\n\u003cp\u003eThe eyepiece barrel has a series of four grooves machined into the scope side of the barrel. When the eyepiece is first inserted into the scope, before tightening the eyepiece locking collar, the eyepiece should be twisted slightly until one of these grooves engages the pin in the bottom of the eyepiece receptacle. This will keep the eyepiece from twisting in place when the knurled power change collar on the eyepiece is turned to adjust the magnification.\u003c\/p\u003e\n\u003cp\u003eAll lens elements (a sophisticated 6 lens\/4 group design) are fully multicoated with Pentax SMC (Super Multi-Coated) high transmission antireflection optical coatings for maximum light transmission and contrast. High refraction\/low dispersion glass elements are used for excellent color fidelity. The eyepiece is specially sealed to be weatherproof under the worst observing conditions a birder might encounter, short of total submersion. Protective caps are provided for both ends of the eyepiece.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e10-14mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e110'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e19.5mm-6.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":40481971470409,"sku":"PXFZ","price":289.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19639.jpg?v=1675378807"},{"product_id":"pentax-16-5mm-xw-extra-wide-angle-eyepiece","title":"Pentax 16.5mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis medium focal length Pentax is a dual-purpose eyepiece for both terrestrial and astronomical observing.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is an excellent moderate power eyepiece for detailed long- and medium-distance nature studies with the 80mm and 100mm Pentax spotting scopes under virtually any lighting conditions, dawn to dusk.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eit provides superb medium power wide field lunar and planetary observing with long focal length refractors, reflectors, or catadioptric scopes. With short focal length refractors and fast focal ratio reflectors, it gives a \"picture window on space\" image. An f\/4.5 Dobsonian reflector, for example, will yield a 3.1mm exit pupil, for bright images of emission nebulas and galaxies. Its sharpness across the field makes smaller globular clusters vivid and nearly three-dimensional. The 650mm focal length TMB-105 triplet apo refractor provides 39x, a 2.25mm exit pupil, and a 1.3-degree field (almost three times as wide as the Moon). These figures are all very usable for observing open clusters such as the Pleiades, large nebulas such as the Lagoon, and large globulars such as M-13. All will fit nicely into the field of view, with a framework of black velvet around them to set off their subtleties.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 36x magnification and a 102' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 37x magnification and a 99' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 45x magnification and an 81' field of view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e102'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e16.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e12.9 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":41750945103945,"sku":"PXW16","price":526.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/Eyepieces_Square4-e1671044738543.png?v=1726598770"},{"product_id":"pentax-23mm-xw-extra-wide-angle-eyepiece","title":"Pentax 23mm XW Extra Wide Angle Eyepiece","description":"\u003cp\u003eThis medium focal length Pentax provides sharp and very wide field images for both terrestrial and astronomical observing.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTerrestrially, \u003c\/em\u003eit is an excellent medium power wide field eyepiece for detailed close-in or wide field nature studies with the 80mm and 100mm Pentax spotting scopes in overcast and sub-par light conditions, dawn to dusk.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eAstronomically, \u003c\/em\u003eits six lens\/four group design makes it an excellent high-contrast choice for medium power deep space observing with long focal length refractors, reflectors, or catadioptric scopes. It is a superb low power eyepiece with short focal length refractors and fast focal ratio reflectors. An f\/4.5 Dobsonian reflector, for example, will yield a 4.4mm exit pupil, excellent for detailed images of emission nebulas and galaxies. Its sharpness across the field makes globular clusters and nebulas vivid and nearly three-dimensional. The 650mm focal length TMB-105 triplet apo refractor provides 28x, a 4mm exit pupil, and a 2.15-degree field (over four times as wide as the Moon). These figures are all very usable for observing open clusters such as the Pleiades; large nebulas such as the Lagoon, Veil, and Orion; and large globulars such as M-13 and Omega Centauri. All will fit nicely into the field of view, with a generous framework of black velvet sky around them to set off their subtleties.\u003c\/p\u003e\n\u003cp\u003eThe long 20mm eye relief is ideal for those who \u003cem\u003emust \u003c\/em\u003e wear eyeglasses while observing due to astigmatism. Even those who do not wear glasses will find the long eye relief a comfortable change from the cramped eye relief that is typical of the usual short focal length eyepiece.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor terrestrial observing . . . \u003cbr\u003e\u003c\/strong\u003eWith an 80mm straight-through Pentax spotting scope this eyepiece provides 25x magnification and a huge 147' field of view at 1000 yards, which are the values given in the specifications to the left. \u003cbr\u003eWith the 80mm \u003cem\u003eangled \u003c\/em\u003ePentax spotting scope this eyepiece provides 26x magnification and a 141' field of view at 1000 yards. \u003cbr\u003eWith the 100mm aperture Pentax spotting scope this eyepiece provides 32x magnification and a big 115' field of view.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor astronomical observing . . . \u003cbr\u003e\u003c\/strong\u003eThe field of view of 70° degrees given in the specifications to the left is the apparent field of view. The actual field of view will be equal to that apparent field divided by the magnification of the eyepiece\/telescope combination.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e70\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eField of view 1000 yards\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e147'\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e23mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e12.6 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003eLimited Lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Pentax","offers":[{"title":"Default Title","offer_id":41750945267785,"sku":"PXW23","price":546.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/Eyepieces_Square3-e1671044714574.png?v=1726598938"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/collections\/36308A4E-2463-4891-936A-04FCA070E844.png?v=1678527150","url":"https:\/\/astronomics.com\/collections\/pentax.oembed?page=2","provider":"Astronomics","version":"1.0","type":"link"}