{"title":"iOptron Imaging Newtonian Telescopes","description":"\u003cp\u003eiOptron Imaging Newtonians are fast f\/4 reflectors designed for deep-sky astrophotography, gathering a lot of light in short exposures. The range includes 150mm, 200mm, 250mm and 300mm apertures.\u003c\/p\u003e\u003cp\u003eThe f\/4 focal ratio gives wide fields with the smaller tubes and more image scale with the larger ones. As with any fast Newtonian, a coma corrector is recommended to keep stars round to the edge of the frame.\u003c\/p\u003e","products":[{"product_id":"ioptron-150mm-f-4-imaging-newtonian","title":"iOptron 150mm f\/4 Imaging Newtonian","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e150mm (6\") Newtonian Reflector\u003c\/li\u003e\n\u003cli\u003e600mm Focal Length\u003c\/li\u003e\n\u003cli\u003eFast f\/4 Focal Ratio\u003c\/li\u003e\n\u003cli\u003e10:1 Dual-Speed Crayford Focuser\u003c\/li\u003e\n\u003cli\u003eOTA Weight: 9 lbs. 10 oz.\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\u003eiOptron 150mm f\/4 Imaging Newtonian\u003c\/h2\u003e\n\u003cp\u003eThe iOptron 150mm f\/4 Imaging Newtonian is engineered for one primary purpose: capturing wide-field deep-sky images with minimal exposure time. Its 150mm aperture gathers significant light, while the fast f\/4 focal ratio and 600mm focal length create a bright, expansive field of view ideal for large nebulae and galaxies. Weighing just 9 lbs. 10 oz., this optical tube assembly (OTA) is built to perform on a wide range of mid-sized equatorial mounts without demanding observatory-class capacity.\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\u003eFast f\/4 Optics: 150mm Aperture for Wide-Field Imaging\u003c\/h3\u003e\n\u003cp\u003eThe optical system's f\/4 focal ratio is its defining feature, allowing you to collect four times the light in a given period compared to an f\/8 system of the same aperture. This dramatic reduction in exposure time means you can capture fainter details in objects like the North American Nebula (NGC 7000) or the Andromeda Galaxy (M31) before tracking errors or skyglow can degrade the image. The 600mm focal length is a sweet spot, providing enough image scale to resolve details in star clusters while being wide enough to frame entire nebular complexes with a typical APS-C or smaller sensor.\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\u003eImaging-Ready Mechanics: A 10:1 Focuser in a 9 lb. OTA\u003c\/h3\u003e\n\u003cp\u003eAchieving critical focus is non-negotiable with a fast optical system, and the included 10:1 dual-speed Crayford focuser provides the necessary precision for the task. The fine-focus knob allows for minute adjustments, ensuring your stars are perfectly sharp. At a manageable 22 inches in length and a weight of 9 lbs. 10 oz., this OTA pairs well with modern, transportable equatorial mounts. A 2-inch, 35mm long extension tube is included to help achieve the correct spacing for various cameras and accessories.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eComa Correction (Required):\u003c\/strong\u003e Like all fast Newtonian reflectors, this f\/4 optical system will exhibit coma at the edges of the field. A third-party coma corrector is essential to achieve sharp, point-like stars across your entire imaging sensor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting Hardware (Required):\u003c\/strong\u003e This is an optical tube assembly only. You will need to supply your own tube rings and a dovetail mounting bar appropriate for your equatorial mount.\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 kind of mount is needed for the iOptron 150mm f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an OTA weight of 9 lbs. 10 oz., you should use a German Equatorial Mount with a payload capacity of at least 20-25 lbs for imaging. This ensures stability and tracking accuracy. Mounts like the iOptron GEM28 or CEM26, or other similar-class mounts, are a good match.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I absolutely need a coma corrector with this iOptron f\/4 telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. For astrophotography, a coma corrector is considered an essential accessory for any Newtonian telescope with a focal ratio of f\/5 or faster. Without one, stars towards the edge of your images will appear elongated or comet-shaped. A corrector will ensure your stars are round and sharp across the entire frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the iOptron 150mm f\/4 perform on the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis telescope is exceptionally well-suited for imaging the Andromeda Galaxy. Its 600mm focal length, when paired with a common APS-C sensor, can frame the entire galaxy, including its faint outer arms and satellite galaxies M32 and M110. The fast f\/4 optics will help you capture significant detail and color in the dust lanes with relatively short sub-exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the iOptron 150mm f\/4 good for viewing or imaging planets like Jupiter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can certainly see planets with this telescope, it is not its primary design. The short 600mm focal length is optimized for wide-field deep-sky objects, not high-magnification planetary work. To get a detailed view of Jupiter's cloud bands or Saturn's rings, you would need to use a high-quality 3x or 5x Barlow lens to increase the effective focal length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the included 2\" extension tube for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe included 35mm long, 2\" diameter extension tube is used to help your camera reach focus. Different cameras (DSLR, mirrorless, dedicated astronomy cameras) have different sensor depths. The extension tube adds extra length to the focuser drawtube, ensuring you have enough \"out-travel\" to achieve a sharp focus with your specific imaging setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this iOptron imaging newtonian come with tube rings and a dovetail bar?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this product is the optical tube assembly (OTA) only. It does not include tube rings or a dovetail mounting bar. You will need to purchase these items separately based on the 7-inch outside diameter of the tube and the type of saddle plate on your mount (Vixen-style or Losmandy-style).\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eNewtonian Reflector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e150mm (6\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e600mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e10:1 Dual-Speed Crayford\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Length\u003c\/td\u003e\n\u003ctd\u003e22 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Outside Diameter\u003c\/td\u003e\n\u003ctd\u003e7 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e9 lbs. 10 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Extension Tube\u003c\/td\u003e\n\u003ctd\u003e2\" Diameter, 35mm Length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003e17 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e26 x 15 x 10 inches\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\"\u003e150mm f\/4 Imaging Newtonian OTA\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2\" Extension Tube (35mm)\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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/ioptron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eiOptron 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":47391546769693,"sku":"IOP-6311","price":641.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/iOptron-150mm-imaging-newtonian.jpg?v=1704394648"},{"product_id":"ioptron-200mm-f-4-imaging-newtonian","title":"iOptron 200mm f\/4 Imaging Newtonian","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e200mm (8\") Newtonian Reflector\u003c\/li\u003e\n\u003cli\u003e800mm Focal Length\u003c\/li\u003e\n\u003cli\u003eFast f\/4 Focal Ratio\u003c\/li\u003e\n\u003cli\u003e10:1 Dual-Speed Crayford Focuser\u003c\/li\u003e\n\u003cli\u003eOTA Weight: 20 lbs 6 oz\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\u003eiOptron 200mm f\/4 Imaging Newtonian\u003c\/h2\u003e\n\u003cp\u003eThe iOptron 200mm f\/4 Imaging Newtonian combines a large 200mm aperture with a fast 800mm focal length, creating an f\/4 optical system designed for deep-sky astrophotography. Weighing in at 20 lbs 6 oz, this Optical Tube Assembly (OTA) is built to gather significant light on large targets while remaining manageable for a wide range of equatorial mounts. The design is centered around a 10:1 dual-speed Crayford focuser, delivering the critical focus precision required for modern imaging sensors.\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\u003e200mm f\/4 Optics: Capture More Light in Less Time\u003c\/h3\u003e\n\u003cp\u003eThe core of this telescope is its fast f\/4 optical system. Compared to a more common f\/5 Newtonian of the same aperture, an f\/4 instrument captures the same amount of light in significantly less time, allowing you to complete projects faster or go deeper on faint targets. The 200mm primary mirror provides ample light-gathering power to resolve details in galaxies and bring out faint structures in nebulae, while the 800mm focal length offers a wide field of view perfect for framing large targets like the Andromeda Galaxy (M31) or the Veil Nebula complex.\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\u003eImaging-Ready Mechanics: A 10:1 Crayford Focuser and 20 lb OTA\u003c\/h3\u003e\n\u003cp\u003eAchieving perfect focus with a fast optical system is critical, and the included 10:1 dual-speed Crayford focuser is built for this task. The fine-focus knob allows for minute adjustments, eliminating image shift and ensuring stars are perfectly sharp. At a weight of 20 lbs 6 oz and a length of 27.75 inches, this OTA requires a stable equatorial mount in the 40-pound payload class or higher for reliable, long-exposure imaging. The package also includes a 35mm-long, 2-inch diameter extension tube to help achieve focus with a variety of camera and accessory combinations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe f\/4 Advantage: iOptron 200mm vs. a Standard f\/5 Newtonian\u003c\/h3\u003e\n\u003cp\u003eWhile an f\/5 Newtonian is often more forgiving to collimate and exhibits less natural coma, the iOptron 200mm f\/4 provides one overriding benefit for the dedicated imager: speed. Shorter sub-exposures reduce the demands on your mount's tracking and autoguiding, which can be the difference between a successful night and a lost one. This speed allows you to gather more data in the limited hours of darkness, a crucial factor for producing high-quality images. To get the most out of this OTA, precise collimation and the use of a third-party coma corrector are essential to achieve sharp stars across the entire field.\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 kind of mount do I need for the iOptron 200mm f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor astrophotography, the OTA's weight of \u003cstrong\u003e20 lbs 6 oz\u003c\/strong\u003e requires a robust equatorial mount. As a general rule, the OTA weight should not exceed 50-60% of the mount's stated payload capacity. Therefore, a mount with a payload capacity of at least 40 lbs is recommended for stable, long-exposure imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the 10:1 dual-speed Crayford focuser on this 200mm Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e10:1 dual-speed focuser\u003c\/strong\u003e is critical for imaging with a fast f\/4 telescope. The coarse knob allows for quick initial focusing, while the fine-adjustment knob moves the focuser drawtube ten times slower. This precision is necessary to hit the very narrow critical focus zone of an f\/4 system, ensuring your stars are as sharp as possible.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a coma corrector with the iOptron 200mm f\/4 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. All fast Newtonian reflectors inherently produce an optical aberration called coma, which makes stars at the edge of the field of view appear elongated. For imaging, a coma corrector is considered an essential accessory to achieve sharp, point-like stars across the entire sensor. This OTA does not include one.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 800mm focal length of the iOptron Newtonian affect my choice of deep-sky targets?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e800mm focal length\u003c\/strong\u003e provides a relatively wide field of view, making it ideal for large deep-sky objects. It is perfectly suited for framing targets such as:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe North America Nebula (NGC 7000)\u003c\/li\u003e\n\u003cli\u003eThe Andromeda Galaxy (M31)\u003c\/li\u003e\n\u003cli\u003eThe Orion Nebula (M42)\u003c\/li\u003e\n\u003cli\u003eThe Veil Nebula complex in Cygnus\u003c\/li\u003e\n\u003c\/ul\u003e\nFor smaller targets like most galaxies and planetary nebulae, this focal length still provides enough image scale to capture significant detail.\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the iOptron 200mm f\/4 Newtonian good for planetary imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile this telescope is optimized for deep-sky imaging, it can be used for planetary work. To achieve the high magnification needed for planets like Jupiter and Saturn, you will need to use a 3x or 5x Barlow lens. This will increase the effective focal length and make it easier to capture fine details in planetary atmospheres. However, its primary strength remains wide-field, deep-sky astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the included 35mm extension tube do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe included \u003cstrong\u003e2\" diameter, 35mm extension tube\u003c\/strong\u003e is used to push the camera further back from the focuser to reach the focal plane. Depending on your specific camera, filter wheel, or off-axis guider, you may need this extra back-focus travel. It threads into the focuser to provide a rigid, non-flexing extension.\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eNewtonian Reflector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e200mm (8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e800mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e10:1 dual-speed Crayford\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Length\u003c\/td\u003e\n\u003ctd\u003e27.75 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Outside Diameter\u003c\/td\u003e\n\u003ctd\u003e9.5 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e20 lbs 6 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Extension Tube\u003c\/td\u003e\n\u003ctd\u003e2\" diameter, 35mm length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003e29 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e34 x 16 x 13 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThis product includes the Optical Tube Assembly (OTA) and a 35mm extension tube only. Tube rings, a dovetail bar, finder scope, and other mounting accessories are not included.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThis optical tube assembly does not require software and does not have a dedicated manual available for download.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/ioptron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eiOptron 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":47391575441693,"sku":"IOP-6312","price":879.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/iOptron-200mm-Imaging-Newtonian.jpg?v=1704921679"},{"product_id":"ioptron-250mm-f-4-imaging-newtonian","title":"iOptron 250mm f\/4 Imaging Newtonian","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e250mm (10\") Parabolic Primary Mirror\u003c\/li\u003e\n\u003cli\u003e1000mm Focal Length\u003c\/li\u003e\n\u003cli\u003eFast f\/4 Focal Ratio\u003c\/li\u003e\n\u003cli\u003e10:1 Dual-Speed Focuser\u003c\/li\u003e\n\u003cli\u003e34 lb 1 oz Optical Tube Assembly Weight\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\u003eiOptron 250mm f\/4 Imaging Newtonian\u003c\/h2\u003e\n\u003cp\u003eThe iOptron 250mm f\/4 Imaging Newtonian combines a massive 250mm aperture with a fast f\/4 optical system to create a powerful instrument for deep-sky astrophotography. Its 1000mm focal length provides an ideal image scale for capturing galaxies and nebulae, while the 34 lb 1 oz optical tube assembly is built for serious imaging platforms. Fine focusing is achieved with a 10:1 dual-speed focuser, ensuring critically sharp stars across your field of view.\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\u003e250mm f\/4 Optics: A Wide-Field, Light-Gathering Powerhouse\u003c\/h3\u003e\n\u003cp\u003eThe heart of this telescope is its 250mm (10-inch) primary mirror. This large aperture gathers a tremendous amount of light, allowing you to resolve faint details in distant celestial objects. Paired with a fast f\/4 focal ratio, this Newtonian drastically reduces required exposure times compared to slower f\/8 or f\/10 systems, letting you collect more data in a single night.\u003c\/p\u003e\n\u003cp\u003eThe 1000mm focal length offers a generous field of view, perfect for framing large targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000). For imagers using modern CMOS or DSLR cameras, this combination of aperture and speed is purpose-built for capturing high-signal, low-noise images of the deep sky.\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\u003eImaging-Ready Design: 34 lb OTA with a 10:1 Dual-Speed Focuser\u003c\/h3\u003e\n\u003cp\u003eEngineered for astrophotography, this OTA includes critical features for obtaining the best results. The 10:1 dual-speed focuser allows for precise, minute adjustments, which is essential for achieving perfect focus at a fast f\/4 focal ratio. An included 2-inch, 35mm long extension tube helps ensure your camera can reach focus with various imaging train configurations.\u003c\/p\u003e\n\u003cp\u003eAt 34 lb 1 oz, the optical tube requires a substantial equatorial mount with sufficient payload capacity to ensure stable, accurate tracking for long exposures. The 12-inch outside diameter means standard, widely available tube rings and accessories will be compatible with this instrument.\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\u003e250mm vs. 200mm Newtonians: The 56% Light-Gathering Advantage\u003c\/h3\u003e\n\u003cp\u003eWhen choosing an imaging Newtonian, aperture is a primary consideration. Compared to a smaller 200mm (8-inch) Newtonian, the iOptron 250mm model offers a significant step up in light-gathering capability.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight Grasp:\u003c\/strong\u003e A 250mm mirror has approximately 56% more surface area than a 200mm mirror. This translates directly into brighter images and the ability to capture fainter details in the same amount of time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResolution:\u003c\/strong\u003e The larger aperture also provides higher theoretical resolution, allowing you to resolve finer details in globular clusters like M13 or planetary nebulae like the Ring Nebula (M57), assuming good seeing conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount Requirements:\u003c\/strong\u003e The trade-off for this increase in aperture is weight. The 34 lb 1 oz OTA weight necessitates a more robust (and costly) mount than a typical 8-inch Newtonian requires.\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 kind of mount is required for the iOptron 250mm f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an optical tube weight of \u003cstrong\u003e34 lb 1 oz\u003c\/strong\u003e, you will need a robust equatorial mount. For imaging, a good rule of thumb is to keep the payload at 50-60% of the mount's stated capacity. Therefore, a mount in the 60-70 lb payload class (like an iOptron CEM70 or similar) is recommended for stable, precise tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the f\/4 focal ratio of the iOptron 250mm Newtonian affect imaging times?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe f\/4 focal ratio is considered very fast in astrophotography. Compared to an f\/8 system of the same aperture, an f\/4 system is four times faster. This means you can capture the same amount of signal in one-quarter of the time, allowing you to complete projects more quickly or go deeper on faint targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the iOptron 250mm f\/4 Newtonian suitable for visual astronomy?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile designed for imaging, this telescope is also a capable visual instrument. The large \u003cstrong\u003e250mm aperture\u003c\/strong\u003e will provide stunning, bright views of deep-sky objects. However, the f\/4 focal ratio will be demanding on eyepieces and will show significant coma away from the center of the field without a visual coma corrector.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat accessories are needed to start imaging with the iOptron 250mm f\/4 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis product is an Optical Tube Assembly (OTA) only. To begin imaging, you will need to supply several key components separately:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTube Rings and a Dovetail Plate:\u003c\/strong\u003e To attach the telescope to your mount.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA Coma Corrector:\u003c\/strong\u003e Essential for achieving sharp stars across the field with a fast f\/4 Newtonian.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA Finder Scope or Guide Scope:\u003c\/strong\u003e For locating objects and autoguiding.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAn Equatorial Mount:\u003c\/strong\u003e With sufficient payload capacity (see above).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA Camera:\u003c\/strong\u003e A dedicated astronomy camera or DSLR.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the iOptron 250mm f\/4 Newtonian perform on large targets like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e1000mm focal length\u003c\/strong\u003e combined with the f\/4 speed makes it an excellent choice for large targets like M31. When paired with a camera sensor like an APS-C or even full-frame (with a suitable coma corrector), you can frame the entire galaxy, including its faint outer arms, in a single shot while the \u003cstrong\u003e250mm aperture\u003c\/strong\u003e resolves dust lanes and star-forming regions within its spiral structure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a coma corrector with the iOptron 250mm f\/4 Imaging Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, for imaging, a coma corrector is considered mandatory for an f\/4 Newtonian. Coma is an optical aberration inherent to parabolic mirrors that makes stars at the edge of the field appear comet-shaped. A coma corrector is a lens assembly that corrects this, ensuring pinpoint stars across your entire camera sensor.\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eNewtonian\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e250mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1000mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e10:1 dual-speed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e34lb. 1oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutside Diameter\u003c\/td\u003e\n\u003ctd\u003e12 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExtension Tube\u003c\/td\u003e\n\u003ctd\u003e2\" diameter 35mm L |\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Length\u003c\/td\u003e\n\u003ctd\u003einches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGross Weight (Shipping)\u003c\/td\u003e\n\u003ctd\u003e48 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e44 x 20 x 18 in\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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/ioptron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eiOptron 2-Year Telescope Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":47391767822621,"sku":"IOP-6313","price":1119.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/iOptron-250mm-Imaging-Newtonian.jpg?v=1704921597"},{"product_id":"ioptron-300mm-f-4-imaging-newtonian","title":"iOptron 300mm f\/4 Imaging Newtonian","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eClear Aperture:\u003c\/strong\u003e 300mm (11.8\")\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal Ratio:\u003c\/strong\u003e f\/4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal Length:\u003c\/strong\u003e 1200mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOTA Weight:\u003c\/strong\u003e 48 lbs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocuser:\u003c\/strong\u003e 10:1 dual-speed\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\u003eiOptron 300mm f\/4 Imaging Newtonian\u003c\/h2\u003e\n\u003cp\u003eThe iOptron 300mm f\/4 Imaging Newtonian combines a massive 300mm (11.8\") primary mirror with a fast f\/4 optical system to deliver a powerful instrument for deep-sky astrophotography. Its 1200mm focal length provides ideal image scale for large nebulae and galaxies, while the 48 lb optical tube assembly is built for stability. A precision 10:1 dual-speed focuser ensures you can achieve the critical focus required by the fast optical design.\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\u003e300mm Aperture and f\/4 Speed for Deep-Sky Imaging\u003c\/h3\u003e\n\u003cp\u003eThe core of this telescope is its large 300mm aperture, which gathers a tremendous amount of light to resolve faint details in distant galaxies and nebulae. Paired with a fast f\/4 focal ratio, this instrument significantly reduces required exposure times, allowing you to capture more data in a single night compared to slower f\/8 or f\/10 systems. This speed is a critical advantage for capturing faint, extended objects from the Messier and NGC catalogs.\u003c\/p\u003e\n\u003cp\u003eIt is important to note that all fast Newtonian reflectors exhibit coma at the edge of the field. To achieve pinpoint stars across the entire frame, pairing this OTA with a high-quality coma corrector is essential for serious 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\u003eA 48 lb OTA with a 10:1 Dual-Speed Focuser\u003c\/h3\u003e\n\u003cp\u003eThis optical tube weighs in at a substantial 48 lbs and measures 45.5 inches in length, demanding a robust equatorial mount for stable, untrailed astrophotography. Mounts in the CEM70, EQ6-R, or a higher payload class are required to carry this instrument effectively. The solid construction ensures that the optical elements remain aligned during long imaging sessions.\u003c\/p\u003e\n\u003cp\u003eFor astrophotography, precise focus is non-negotiable. The included 10:1 dual-speed focuser allows for extremely fine adjustments, which is critical for hitting the narrow critical focus zone of an f\/4 optical system. This ensures your images are as sharp as the optics will allow.\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\u003eFraming Large Nebulae at a 1200mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eThe 1200mm focal length provides a versatile image scale that is well-suited for a wide range of deep-sky targets. It can comfortably frame large objects like the Andromeda Galaxy (M31) or the Orion Nebula (M42) using common APS-C or full-frame sensors. This makes it an ideal workhorse for capturing showcase celestial objects in high resolution.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-Field Capability:\u003c\/strong\u003e Captures expansive nebulae and star clusters in a single frame.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Extension Tube:\u003c\/strong\u003e A 2-inch, 35mm long extension tube is included to help achieve the correct spacing for various cameras and accessory combinations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Resolution Views:\u003c\/strong\u003e The combination of large aperture and moderate focal length resolves fine details in planetary nebulae and globular clusters like the Hercules Cluster (M13).\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 kind of mount is required for the 48 lb iOptron 300mm f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eDue to its 48 lb weight and 45.5-inch length, a heavy-duty equatorial mount is mandatory for astrophotography. Look for mounts with a payload capacity of at least 60-70 lbs to ensure stability and reliable tracking. Mounts like the iOptron CEM70, Sky-Watcher EQ8-R, or similar are appropriate choices.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the iOptron 300mm f\/4 Imaging Newtonian frame a target like the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith its 1200mm focal length, this telescope will provide a relatively tight field of view that is perfect for capturing the core of the Orion Nebula (M42), including the Trapezium, in high detail with most astronomy cameras. On a camera with an APS-C sensor, you will frame the brightest regions of the nebula beautifully, while a full-frame sensor will capture more of the surrounding nebulosity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a coma corrector with this iOptron Imaging Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. It is highly recommended. The fast f\/4 focal ratio inherent to this telescope's design will naturally produce coma, an optical aberration that makes stars at the edge of the field of view appear elongated. A coma corrector is a necessary accessory to achieve sharp, round stars across your entire image sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is an f\/4 focal ratio important for an imaging telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn f\/4 system is considered \"fast\" because it allows the camera sensor to collect the same amount of light in a fraction of the time compared to a \"slower\" telescope (like an f\/8 or f\/10). For example, an f\/4 scope gathers light four times faster than an f\/8 scope. This means shorter sub-exposures, less chance for tracking errors to ruin a shot, and more total imaging time in a single session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the 10:1 dual-speed focuser used for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 10:1 dual-speed focuser provides two focusing knobs. The larger knob makes coarse adjustments to get the image roughly in focus. The smaller knob moves the focuser 1\/10th as much for each rotation, allowing for the extremely precise, fine adjustments needed to achieve perfect focus for sharp, high-resolution astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the included 2\" 35mm extension tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 35mm extension tube is used to adjust the spacing between the focuser and your camera. Different cameras, filter wheels, and off-axis guiders require different amounts of back focus. The extension tube helps ensure you can reach focus with a variety of imaging train configurations.\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eNewtonian\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e300mm (11.8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1200mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e10:1 dual-speed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Length\u003c\/td\u003e\n\u003ctd\u003e45.5 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Outside Diameter\u003c\/td\u003e\n\u003ctd\u003e14 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e48 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExtension Tube\u003c\/td\u003e\n\u003ctd\u003e2\" diameter, 35mm length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Weight \u0026amp; Dimensions\u003c\/td\u003e\n\u003ctd\u003e65 lbs, 52 x 22 x 20 inches\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\"\u003e300mm f\/4 Newtonian Optical Tube Assembly\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2\" Extension Tube (35mm)\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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/ioptron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eiOptron 2-Year Telescope and 1-Year Accessory Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":47391792136477,"sku":"IOP-6315","price":1539.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/iOptron-300mm-Imaging-Newtonian.jpg?v=1704921633"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/ioptron-imaging-newtonian-telescopes.oembed","provider":"David Astro","version":"1.0","type":"link"}