{"product_id":"baader-sundancer-ii-telecentric-system-tz-3s","title":"Baader SunDancer II Telecentric System","description":"\u003ch1\u003eBaader SunDancer II Telecentric System\u003c\/h1\u003e\n\u003cul\u003e\n\u003cli\u003eAchromatic 3x telecentric system\u003c\/li\u003e\n\u003cli\u003eFour-lens optical design, BBAR (Broad-Band Anti-Reflection) coating\u003c\/li\u003e\n\u003cli\u003eAnti-reflective thread and blackened lens edges against reflections and for maximum contrast\u003c\/li\u003e\n\u003cli\u003eImage circle 35mm in 65 mm distance to T-2 threaded base\u003c\/li\u003e\n\u003cli\u003e1¼\" and 2\" nosepiece with 1¼\" filter thread, T-2 thread on camera side\u003c\/li\u003e\n\u003cli\u003eThe optical design places the telescope's focal point 28 mm behind the end of the 1¼\" nosepiece\u003c\/li\u003e\n\u003cli\u003e5-year warranty if handled properly\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: when using as a telecentric for H-alpha or CaK solar observation, it is mandatory to include a suitable D-ERF filter in front of the telescope aperture to prevent damage to the lens groups in the telecentric due to overheating. Heat\/melting damage is not a warranty case, but only occurs due to improper operation.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch2\u003eBaader SunDancer II 3x Telecentric System TZ-3S\u003c\/h2\u003e\n\u003cp\u003eTelecentric systems are mainly used in H-alpha filters for solar observation, where the 1\/100 lambda plane-parallel etalon in the H-alpha filter requires a perfectly parallelised beam of light over the entire image. These telecentrics deliver very sharp images, but are usually only optimised for the H-alpha wavelength.\u003cbr\u003e\u003cbr\u003eThis\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eachromatic SunDancer 3x telecentric\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis designed for the entire visible spectrum and can therefore not only be used on H-alpha systems, but also replace a Barlow lens. Due to the parallel beam of light, it is very good-natured with regard to the working distance: While the magnification factor of a Barlow lens changes with the distance to eyepiece or camera (zoom eyepieces are also based on this principle), the magnification factor and image quality of the TZ-3 do not change, even if the new focal point deviates very significantly from the working distance of the optical design (65 mm).\u003cbr\u003e\u003cbr\u003eThe achromatic SunDancer II TZ-3S illuminates an image circle of 35mm at a distance of 65mm from the base body, ideal for the small sensors of modern, fast planetary cameras that require high magnifications for photographing the moon and planets. The contrast is better than with simple barlows or the eyepiece projection often used for high magnifications. With the 3x telecentric system, the high magnifications which are necessary for visual observations can also be achieved with long focal length orthoscopic eyepieces. The interpupillary distance of the eyepieces used does not change either.\u003cbr\u003e\u003cbr\u003eThe connection on the telescope side is made via a dual 1.25\"\/2\" nosepiece with safety kerfs (these prevent tilting due to an incorrectly positioned safety groove and at the same time provide a secure hold). On the camera side, the T-2 thread provides a tilt-proof, fixed connection even to heavy cameras or to T-2 eyepiece clamps. For the T-2 thread, adapter rings are available for almost all common connection systems (e.g. M48 \/ 2\"\/ M68).\u003c\/p\u003e\n\u003ch2\u003eComparing telecentric systems with Barlow lenses\u003c\/h2\u003e\n\u003cp\u003eA telecentric system extends the focal length similar to a Barlow lens, but with parallel rays of light. This means that the working distance is almost the same, and the quality and image scale remain the same. At the same time, the TZ-3S delivers a high-contrast image. For the following comparison shot, a church steeple was photographed with an APS-C DSLR with the same camera settings; once with a Baader Q-Barlow, which was brought to a triple magnification factor with spacer sleeves, and once with the TZ-3S. On cameras with less than 35mm image circle, edge shading is no longer a problem and you benefit from higher contrast of the telecentric.\u003c\/p\u003e\n\u003ch2\u003eComparison of Baader SunDancer II H-alpha-Filter and Baader SunDancer II TZ-3S\u003cbr\u003e\n\u003c\/h2\u003e\n\u003cp\u003eThe telecentric system of the Baader SunDancer II H-alpha Filter (#1363056, € 3345,-) is the same as the Baader SunDancer II 3x telecentrics TZ-3S, but additionally contains a 2nm (FWHM) blocking filter. It shimmers golden when you look into the SunDancer from the telescope side. This blocking filter is absolutely necessary to protect the actual H-alpha filter from solar radiation. The 3x telecentric system is available as Baader SunDancer II 3x Telecentric TZ-3S without block filter, e.g. for use with other H-alpha filters. The blocking filter, however, is not available separately.\u003cbr\u003e\u003cbr\u003eThe blocking filter reflects the sunlight just before the etalon and the telecentric system. This protects the etalon from excessive heat. In addition, an etalon also transmits wavelengths that are a multiple of the desired transmission line; these are also blocked by the blocking filter, too.\u003c\/p\u003e\n\u003cp\u003eTZ-optical systems are essential for undeteriorated performance of heated SolarSpectrum filters:\u003c\/p\u003e\n\u003cp\u003ePlease note that for H-alpha observations below 1 Ang halfbandwidth (FWHM) a telecentric lens system is absolutely mandatory, in order to achieve the recommended focal ratio of f\/30 to (preferably) f\/40! Because only with a telecentric approach you can create a perfectly parallel optical path which is essential for the unrestricted function of such a complicated etalon.\u003cbr\u003e\u003cbr\u003eA TZ-lens-system is an ESSENTIAL prerequisite. One could also optically - or by means of a Barlow lens - bring a telescope to a focal ratio of f\/30, but this does not mean at all that a parallel optical path is created. And mind you, a still slightly conical optical path with f\/30 sent into an etalon with 0.5 Ang FWHM would only provide the contrast as if the filter had a FWHM of 0.7 Ang or much worse.\u003cbr\u003e\u003cbr\u003eIt doesn't have to be a TZ-4. The 2\" Research Grade TZ-3 Telecentric System (3x focal length) (#2459257) with 46mm clear aperture is much better in terms of optical calculation than the 20 year older TZ-4. So it makes sense for the user to start with a TZ-3 RG and rather stop down the telescope aperture to get to f\/30. This will bring out the real contrast of the chosen SolarSpectrum-filter much better than with a poorly matched system where, for example, the older TZ-4 has a smaller clear aperture than the Solar Spectrum-Etalon would require. In the long run, a newly calculated, large RG TZ-4 is in preparation - it is worth to wait for it and to get familiar with H-alpha observation with the TZ-3 first. In the end one will certainly need both systems (RG-TZ-3 and RG-TZ-4) and adjust the telescope aperture individually - as the system would require to enable an f\/ratio of f\/30 at minimum or f\/40 as optimum.\u003cbr\u003e\u003cbr\u003eOnly AFTER the H-alpha etalon you can extend the field size by reducing the f-ratio with adding the new ResearchGrade telecompressor 0.4 into the optical train.\u003cbr\u003e\u003cbr\u003eBasically - a Barlow lens has no place in an H-alpha system!\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"data-table\"\u003e\n\u003ctbody\u003e\n\u003ctr class=\"first odd\"\u003e\n\u003cth class=\"label\"\u003eMANUFACTURER\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003eBaader Planetarium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"even\"\u003e\n\u003cth class=\"label\"\u003eSKU (#)\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003e1363070\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"odd\"\u003e\n\u003cth class=\"label\"\u003eEAN CODE\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003e4047825042903\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"even\"\u003e\n\u003cth class=\"label\"\u003eFOCAL LENGTH EXTENSION\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003e3x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"odd\"\u003e\n\u003cth class=\"label\"\u003eUSAGE\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003efor H-alpha observation with SolarSpectrum filters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"even\"\u003e\n\u003cth class=\"label\"\u003eOUTER CONNECTION (LENS SIDED)\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003eBarrel, 1¼\", 2\" (50,8mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"last odd\"\u003e\n\u003cth class=\"label\"\u003eOUTER CONNECTION (EYEPIECE\/-CAMERA-SIDED)\u003c\/th\u003e\n\u003ctd class=\"data last\"\u003eThread, T-2 (M42 x 0,75), 1,4\"(35mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eIn the Box\u003c\/h3\u003e\n\u003cp\u003eBaader SunDancer II Telecentric System\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eWarranty \u0026amp; Manuals\u003c\/h3\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/istronomyplus.com\/pages\/baader-warranty\" rel=\"noopener\" target=\"_blank\"\u003eBaader 2-Year Warranty\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0267\/1172\/0013\/files\/baader_sundancer_ii_h_alpha_filter_manual_and_applications_tipps.pdf?v=1631973767\" target=\"_blank\"\u003eBaader SunDancer II H-alpha Filter – Manual and Applications Tipps\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0267\/1172\/0013\/files\/baader_sundancer_ii_quickstart.pdf?v=1631973766\" target=\"_blank\"\u003eBaader SunDancer II - Quickstart\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0267\/1172\/0013\/files\/solarspectrum_h_alpha_filter_baader_planetarium_telecentric_systems_346e0461-a02c-49c7-bbef-768fd3c3e48c.pdf?v=1700410227\" target=\"_blank\"\u003eSolar Spectrum H-alpha-filter and Telecentric Systems - Application and Tips \u003c\/a\u003e\u003c\/p\u003e","brand":"Baader Planetarium","offers":[{"title":"TZ-3S","offer_id":49098869440741,"sku":"BAA-TZ-3S (Baader #1363070)-1","price":532.0,"currency_code":"CAD","in_stock":true},{"title":"TZ-4S","offer_id":49098869473509,"sku":"BAA-TZ-4S (Baader #1363080)","price":561.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/5_31d5080c-d52b-4ae9-b420-4d6ed76e2ff5.webp?v=1739046285","url":"https:\/\/istronomyplus.com\/products\/baader-sundancer-ii-telecentric-system-tz-3s","provider":"Astronomy Plus – Telescopes \u0026 Astrophotography Canada","version":"1.0","type":"link"}