{"product_id":"nakoh-60gt","title":"NAKOH 60GT Astrograph Triplet APO (60GT)","description":"\u003ch2\u003eNAKOH 60GT Astrograph Triplet APO\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eA compact astrograph defined by high quality and exquisite design.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eIts triplet lens design masterfully utilizes one piece of Japan-made SD glass and one piece of ED glass to minimize chromatic aberrations, delivering consistently sharp, high-definition results. Enjoy flat, clear, and stunning stellar views that are maintained from the image center all the way to the 44mm full-frame edge.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe optical performance of the NAKOH 60GT has been rigorously tested using the internationally recognized ZYGO interferometer, with quantitative data demonstrating top-tier excellence.  \u003cbr\u003eThe test report reveals a Strehl ratio as high as 0.976, an RMS value as low as 0.026λ (surpassing λ\/38), and a PV value of 0.168λ. These figures not only far exceed the demanding \"diffraction-limited\" standard (Strehl ratio \u0026gt; 0.8) but also indicate that its imaging quality is virtually unconstrained by mirror precision, allowing celestial details to be concentrated into an exceptionally sharp focus.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp class=\"cur\"\u003e\u003cspan\u003e\u003cstrong\u003eMechanical Features\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1766121997126530.jpg?v=1774374905\"\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eDual-speed metal rack-and-pinion focuser with a 2.5-inch interface, 32mm focusing travel, and high-precision engraved scales.\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eCompatible with most commercially available electronic focusers. The focuser side features a finder base (M4 threaded hole) for additional astronomical accessories.\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe fine adjustment knob includes a protective cap to prevent damage.\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003eEquipped with a 360° high-precision rotator featuring engraved scales, a knurled locking screw allows for secure fixation of the rotation angle.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764314254212398.jpg?v=1774375079\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003e230mm length Vixen-style dovetail plate, equipped with standard threaded holes.\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764314270897506.jpg?v=1774375128\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003eFull metal tube rings with a tilted design for superior fixation. Enlarged thumb locking screws enable easy operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1766122022230175.jpg?v=1774375162\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cspan\u003eFull-metal, detachable handle with a streamlined design for a comfortable grip.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDesign Features\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e* The NAKOH 60GT is a triplet APO astrograph, utilizing one piece of SD glass and one piece of ED glass.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOptical Path Diagram\u003c\/span\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1768801415213511.jpg?v=1774374381\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eIt fully leverages the anomalous dispersion characteristics of both SD and ED glass to significantly reduce differences in the refractive index across various wavelengths. This effectively suppresses chromatic aberration (particularly purple and green fringing) and enhances image sharpness.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e* The imaging quality of the optical system can be evaluated by analyzing the distribution of star points in the image.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e60GT+1.0× Flattener Spot Diagram\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764837271206689.jpg?v=1774374447\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e60GT + 0.65× Reducer Spot Diagram\u003c\/span\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764837282156559.jpg?v=1774374473\"\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe horizontal axis represents the distance of the star point from the image center, while the vertical axis represents the RMS radius of the star point.\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe NAKOH 60GT achieves a central star RMS radius of approximately 2 micrometers, and less than 2.5 micrometers at the edge of the 44mm image circle.\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe stars are sharp and rounded, demonstrating excellent performance across the full frame.\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e60GT Longitudinal chromatic aberration Curve\u003c\/span\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764311738838998.jpg?v=1774374512\"\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe longitudinal chromatic aberration graph uses wavelength (nm) as the horizontal axis and focal shift (μm) as the vertical axis to display differences in the focusing positions of various wavelengths along the optical axis. The NAKOH 60GT exhibits low shift, a gentle curve across the entire wavelength range, and well-aligned curves at key wavelengths, reflecting its excellent chromatic aberration control.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764837318113610.jpg?v=1774374542\"\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764837336155720.jpg?v=1774374561\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe relative illumination uses the field radius as the horizontal axis and relative brightness percentage as the vertical axis to illustrate the attenuation of light from the center to the edge of the field of view. Even at the extreme edges of the full frame, the 60GT maintains high brightness, a smoothly declining curve, and consistency across multiple wavelengths, effectively minimizing vignetting.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764312604192493.jpg?v=1774374594\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eRonchi test\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIn focus\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764313126875470.jpg?v=1774374654\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOut of focus\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764313145695774.jpg?v=1774374684\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThe Ronchi test quantitatively evaluates the surface figure accuracy and optical axis collimation of the objective lens by analyzing shadow patterns. The 60GT demonstrates exceptional performance: both in and out of focus, the shadow variations transition evenly and smoothly, forming straight, symmetrical lines. \u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003eThis conforms to the criteria of an excellent optical system, indicating that the 60GT possesses precise parabolic surface figures and optimal optical alignment.\u003c\/p\u003e\n\u003ch3 class=\"pkg-text\"\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eSamples\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"cur\"\u003eSample1:NGC6960\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764318293214149.jpg?v=1774374790\"\u003e\u003c\/p\u003e\n\u003cp class=\"cur\"\u003e\u003cspan\u003e〈Objects〉IC：NGC6960 photographed by：Zhang Yuhang\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eequipments：NAKOH 60GT + \u003c\/span\u003e\u003cspan\u003eSpecific 1.0× Flattener\u003c\/span\u003e\u003cspan\u003e Camera: ZWO ASI6200MM\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"cur\"\u003eSample2:M45\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764313835676363.jpg?v=1774374835\"\u003e\u003c\/p\u003e\n\u003cp class=\"cur\"\u003e\u003cspan\u003e〈Objects〉IC：M45 photographed by：Qiang\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eequipments：NAKOH 60GT + \u003c\/span\u003e\u003cspan\u003eSpecific \u003c\/span\u003e\u003cspan\u003e0.65× Reducer　Camera: ZWO ASI2600MC\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eTechnical Specification\u003c\/span\u003e\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd align=\"left\" valign=\"middle\" width=\"40%\"\u003eAperture\/Focal Length \/Focal Ratio\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"top\"\u003e60mm \/ 360mm \/ F6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eObjective Lens\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003etriplet APO (incl. 1× SD Glass [made in Japan], 1× ED Glass)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eImage Circle \u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e\n\u003cp\u003eφ44mm (with Reducer\/Flattener)\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eResolving Power\/Limiting Magnitude\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e\n\u003cp\u003e1.93 arc seconds\/10.66 \u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eLight Gathering Power\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e\n\u003cp\u003e73x unaided eyes\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eTube Length\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e270mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eWeight\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e≈2.94kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eRear-end Interface\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e\n\u003cp\u003e1.25-inch \/ 2-inch\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003eStandard Accessories\u003c\/td\u003e\n\u003ctd align=\"left\" valign=\"middle\"\u003e\n\u003cp\u003e60GT，Handle，Tube Ring，Dovetail Plate，1.25-inch Adapter，2-inch Adapter，Instruction Manual ，Warranty Card\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e \u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eProduct Size Diagram \u0026amp; Connection Diagram\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e【Product Size Diagram】\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1768535394584603.jpg?v=1774375237\" alt=\"\"\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cstrong\u003e【Connection Diagram】\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cstrong\u003e * Observation Mode\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cstrong\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764835453166311.jpg?v=1774375272\" alt=\"\"\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cstrong\u003e * Imaging Mode\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e\u003cstrong\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764835472121668.jpg?v=1774375308\" alt=\"\"\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp class=\"cur\"\u003e \u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eIn the box\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan\u003eOptical Tube Assembly (OTA)\u003c\/span\u003e\u003cspan\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310485206209.jpg?v=1774374007\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eHandle\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310495130709.jpg?v=1774374089\"\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eTube Ring\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310504111491.jpg?v=1774374117\"\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eVixen-style Dovetail Plate\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310513409817.jpg?v=1774374145\"\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e1.25-inch Eyepiece Adapter\/ 2-inch Eyepiece Adapter\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310528101927.jpg?v=1774374189\"\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eUserManual\/ WarrantyCard\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764310542213145.jpg?v=1774374224\"\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eWarranty \u0026amp; Manual\u003c\/h3\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/astronomyplus.com\/pages\/nakoh-warranty\" target=\"_blank\" rel=\"noopener\"\u003eNAKOH Warranty\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"pkg-text\"\u003e \u003c\/p\u003e","brand":"NAKOH","offers":[{"title":"Default Title","offer_id":48602872709349,"sku":"NAK-60GT","price":1399.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/1764227275878286.jpg?v=1777043907","url":"https:\/\/astronomyplus.com\/products\/nakoh-60gt","provider":"Astronomy Plus – Telescopes \u0026 Astrophotography Canada","version":"1.0","type":"link"}