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You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Anyway, when purchased my R/C the "original" Celestron unit was not readily available and was offered instead the one sold under the shop's own label (in my case Tecnosky, but I saw the same product offered under TS label). So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. Most Feather Touch focusers cost between $300-$350. It's easy! I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. A focal reducer does just the opposite of a Barlow lens or focal extender. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Field stop diameters are one of the specified specs of eyepieces. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. Nebula Filters. I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. I'm going with the Celestron. A wider field of view and a lower magnification is also useful, with some focal reducers and with some eyepieces, for visual observers with telescopes with long focal ratios. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). CPWI has an extensive object database, employs PointXP mount modeling, and more. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. ), ASI Air Plus - Connected items are 'greyed out', Cost of ordering used equipment U.S. - Can can more than double figure, Tuthill Isostatic Mount and Star Trap Power Module. The lens that the ZWO comes with give a perfect wide angle image of what is in front of it. The Antares is supposed to be pretty comparable. I focus using a moonlight electronic focuser and focusmax. Never used one, but read the reviews here that suggest a coating problem. Please note, orders placed after 10am on 2/28/2023 will be delayed. Style: For example, many focal reducers designed for f/7 or f/8 ED refractors such as those from Tele Vue, William Optics, Sky-Watcher, and Meade are designed to have a working distance (or back focus) of 55mm. I am a purely visual observer, so will evaluate for visual use only. This is the distance at which the reducer must be placed in front of the eyepiece or camera focal plane in order to operate at the design reduction factor. The working distance of the GSO 0.5x focal reducer with 1.25" barrel and the GSO 0.5x focal reducer with 2" barrel is about 51mm to 53mm, approximately, from the middle of the metal cell that holds the lens. However, with appropriate spacers and a camera with a known back-focus, it is easy to determine the exact amount of focal reduction for a given setup (some imaging software packages will also let you derive this from images). A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. Fumbling around in the dark, fine threads might be a problem. Celestron's EdgeHD reducers feature a custom 5 element optical design engineered to maintain the flat-field performance of our award-winning EdgeHD optical system. Unscrew that wide angle lens and put it away, then attach the ASI120 to the nose-piece that came with the camera and fit that into the eyepiece holder. How about for visual observers? Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. Copyright 2021 Stargazers Lounge Well done. Not noticed any optical problems. The visual back must be removed first. For Ritchey-Chretien telescopes such as those manufactured by GSO, there are also dedicated focal reducers with a reduction factor of 0.7x to 0.8x. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; Not a bit. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. . The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. Some are available in 1.25" barrel format but with C threads. Your wishlist has been temporarily saved. Manish Panjwani has been an active amateur astronomer since before Halley's Comet last flew by our neighborhood. This award-winning optical system reduces visual defects like field curvature and coma, creating an ultra-flat field for pinpoint stars all the way to the edge of todays largest imaging sensors. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. Antares' f/6.3 focal reducer provides a faster f/6.3 system for imaging or visual use when used with an f/10 SCT or other compatible telescopes. The female end attaches to the rear cell of the telescope. More details are found in the Appendix of this article. Celestron makes a series of focal reducers for the Edge HD line that are matched to the 8", 9.25", 11", and 14" apertures of these scopes. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Scope size might influence choice as well, as a C6 might benefit from the Antares' transparency, while larger scopes might benefit from the Celestron's higher contrast. They are commonly available in 1.25" and 2" threaded cells that conveniently thread into the nosepiece of a compatible camera or the barrel of an eyepiece. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. You need to be a member in order to leave a comment. In both cases will end with a similar tfov. Please Log in to save it permanently. Not one detectable iota of discernable difference. A couple of tiny dust particles between lens elements, uneven lens edge blackening, very minor coating blemishes, or even a very small fine lens scratch or two are very common in this Antares product and must be accepted as normal for this item. Start here to find the perfect telescope for you! You don't need to follow these equations to use a focal reducer, but they do show how the reduction factor changes with the placement of the reducer. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. We reserve the right to verify a competitor's advertised price and the availability of the item. Most manufacturers provide this specification. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. Explore Scientific - Keys to the Universe Sale. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. One problem with getting opinions is that most of use do not have both reducers or have never done a side by side comparison. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? This filter threads on to the rear cell of your Celestron or Meade SCT telescope. For the best experience on our site, be sure to turn on Javascript in your browser. They never really recovered from selling a few 15 years back with element reversed. control and Sky Viewer display makes selecting your target easy. I was going to measure the difference in grams, but my lovely wife caught me trying to use her precious, high-tech kitchen scale for the cause, and put the kibosh on it. It threads onto the rear cell of 5" to 16" Celestron and Meade Schmidt-Cassegrain telescopes, making it possible to have a dual focal ratio instrument without sacrificing image quality. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. Free shipping $189.95 Theoretically each of these combinations all varied-length light paths should have resulted in slightly different reductions between the Celestron and Antares, since they supposedly have different focal lengths. This superb fully multi-coated multi-element focal reducer takes advantage of the latest computer aided design techniques to achieve the highest standards of performance set by the brand leaders at a fraction of the cost. Bear in mind you can't squeeze blood out of a turnip, i.e. The working distance (backfocus) of the Celestron f/6.3 reducer is specified to be 105mm from the base of the male SCT thread on the camera side. I only have the Celestron f/6.3. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Sky recognition technology that has revolutionized the manual telescope by eliminating the confusion common among beginners and enhancing the user experience for even seasoned telescope users. For visual use, this means you get lower power with the same eyepiece and a wider field of view. In this case, d2 = FR/2, which means the back of the focal reducer is located at a distance FR/2 from the camera or eyepiece. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Check out our 2022 telescope buying guide here! No negative issues to report. Now, Celestron is using that same technology to allow star gazers to connect to the night sky and enhance their experience of the cosmos in fun and unique ways. Thanks guys, appreciate the feedback. JavaScript seems to be disabled in your browser. Request stock alerts and we'll let you know when the item is back in stock. The camera side of the focal reducer is threaded for a T-adapter with wide M48 threads, or in some cases, with smaller M42 threads. and you will be fine. It was used strictly for imaging, not visual observing. I use it on my C8 SCT with a 1000d, and it seems to do everything written on the tin. I must admit, as well, that I no longer place a lot of stock in the notion that Chinese optics are inferior to Japanese or Taiwanese any longer, as manufacturing technology has really leveled the playing field today, with most Chinese optics being excellent. Even though the manufacturer did not specify the working distance or focal length of this reducer, it is easy to see from this plot that this item provides its stated reduction of 0.5x when it is placed at a working distance of 51.5mm between the base of the threads on the mount and the focal plane of the eyepiece or camera. Does anyone have any experience with the Celestron and Antares focal reducers? Focal reducers for refractors are easy to use. Increasing the operating distance, that is, moving a focal reducer away from the eyepiece or camera reduces its reduction factor, or conversely increases the amount of reduction. A reducer is a set of converging (or positive) lenses that cause the light from a telescope objective to converge at a steeper angle to the focal plane as if it were coming from an objective with a faster (lower) focal ratio and a shorter focal length. However, these will not impact optical performance. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Never noticed any anomalies with this unit. The reduction factor MR can also be written in terms of d2 as: When the focal reducer is placed at the working distance, D, that is when d2=D, then the reduction factor MR is equal to the design reduction factor MRD: Equations (6) and (7) imply these important considerations: Most manufacturers do not publish the focal length of their focal reducers, so it is not usually possible to calculate the working distance and design reduction factor. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). Celestrons aplanatic EdgeHD optics revolutionized astroimaging. Read our 101 article or get in touch. Reducer Lens .7x - EdgeHD 925 Learn More. Photographically you also get a wider field and much shorter exposures. I would not use the reducer with a 2" diagonal or eyepiece in the C6. 3. Keep in mind that these differences were very subtle, and could be due to normal variations in coatings among different runs, and not necessarily unique to the brands. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions. It is not a corrector or flattener. October 11, 2010 in Discussions - Scopes / Whole setups. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. At a significantly lower price point, the Antares is a steal, and theres no need to upgrade to the Celestron if you already have one. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? As a real-world example plot showing the above relationships, let's look at the 1.25" GSO focal reducer that provides a design reduction factor of 0.5x. Wow, that is a very detailed discussion! The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. We will be glad to help. My experience is that CN sellers are way above those listing elsewhere. Once focused it's pretty good. Reducer Lens .7x - EdgeHD 800 But I am rusty, can you condense a bit for me please? Just point the telescope at any three bright objectsstars, bright planets, or even the Moonand your telescope can orient itself with the night sky. You also wont be unhappy spending the few extra bucks on the Celestron for the pretty orange lettering, particularly if you can pick one up used, as I did. Wonder how they would stack up with a Japanese 6.3. CPWI has an extensive object database, employs PointXP mount modeling, and more. Thanks for the extremely valuable article. Place the plastic covers on the lens when not in use to reduce the dust collection. But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. The Reducer/Corrector is easy to install by threading the unit onto the rear cell of your Schmidt-Cassegrain telescope (or the reducer plate of the C11 and C14). DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. ), but stars seemed a bit tighter and their colors were richer and more dramatic. Very helpful, thanks a lot for this article! As mentioned in Section 2 of this guide, the reduction factor of a focal reducer depends on its position in the optical path relative to the eyepiece or camera. Unleash the full pointing accuracy of your Celestron computerized telescope with a specialized telescope control software suite. The reducer fits all Meade and Celestron . I wish there was. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. Now It only focuses near things, like some kind of macro zoom. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. I've looked through one from Meade and first impression was that it was like the Celestron version. However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. Unlike SCT telescopes, Ritchey-Chretien telescopes and Celestron Edge HD or Meade ACF scopes have internal optics that provide an inherently flat field, so these telescopes require a special focal reducer than does not provide additional correction for field curvature. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. Stock focusers in an SCT move the mirror of the scope to change the position of the focal plane, and they have sufficient travel to accommodate a focal reducer. No results, please adjust your filters. Years ago, I bought the Antares version, and moved over to the Celestron. This article explains the basics of how focal reducers work with an astronomy telescope. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). You attach the focal reducer to the rear port on a SCT and can keep it covered. The more focal reduction, the further inward the focal plane will be. For both imaging and visual observing, these reducers also improve image sharpness at the edge of the field by correcting for coma and field curvature. The Antares FR2-0.7X is the same 4-element f/6.3 lens system used for f/10 Schmidt-Cassegrain telescopes but in a 2" barrel threaded for standard filters. I have this one Opticstar F6.3 Focal Reducer / Corrector. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. Like many of us with SCTs, I have bought and sold a number of f/6.3 reducer/correctors over the years, and I have always been curious how they really stack up to each other. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Or, when the distance of the focal reducer to the focal plane of the objective d1 equals the focal length of the focal reducer FR, the reduction factor MR = 0.5x. I have an 8SE, and am thinking about getting a focal reducer. Here, there was a subtle difference . That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. Sharpness is essentially the same. Reducer Lens .7x - EdgeHD 925 Opticstar F6.3 Focal Reducer / Corrector. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer.