As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. I've only used it a few times but it looks good to me. In this case, an additional T-adapter (with an optical length of 50mm) is needed to get the spacing correct for a DSLR or other camera with a 55mm back focus. For the best experience on our site, be sure to turn on Javascript in your browser. However I've also read that the back focal distance on the Celestron is 105mm while the Antares is 81mm so they couldn't be identical. This telescope control software replaces the hand control and allows the user to remotely control their Celestron computerized telescope from their personal PC or laptop. 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. https://www.celestron.com/products/reducer-corrector, //cdn.shopify.com/s/files/1/1935/4371/products/94175_reducer_corrector_01.jpg?v=1603736883, //cdn.shopify.com/s/files/1/1935/4371/products/94175_reducer_corrector_01_medium.jpg?v=1603736883, Popular Science by Celestron StarSense Explorer DX 5" Smartphone App-Enabled Schmidt Cassegrain Telescope, Advanced VX 8" Schmidt-Cassegrain Telescope, C9.25 Optical Tube Assembly (CGE Dovetail), Advanced VX 6" Schmidt-Cassegrain Telescope, Advanced VX 700 Maksutov Cassegrain Telescope, CGX-L Equatorial 925 Schmidt-Cassegrain Telescope, CPC 1100 GPS (XLT) Computerized Telescope, CGX-L Equatorial 1400 Schmidt-Cassegrain Telescope, CGX-L Equatorial 1100 Schmidt-Cassegrain Telescope, CGX Equatorial 925 Schmidt-Cassegrain Telescope, CGX Equatorial 800 Schmidt-Cassegrain Telescope, CGX Equatorial 1100 Schmidt-Cassegrain Telescope, CGEM II 1100 Schmidt-Cassegrain Telescope, Advanced VX 9.25" Schmidt-Cassegrain Telescope, Advanced VX 11" Schmidt-Cassegrain Telescope, Not compatible with #93648 Off-Axis Guider, not compatible with #93519 2" Mirror Diagonal (discontinued), Currently not compatible due to mechanical interferences. In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. In every configuration, there were essentially parfocal, requiring only a tiny fine focus adjustment when changing correctors. Great for home, classroom, or home-school use, this kit includes all the essential items youll need to begin exploring the wonders of the microscopic world. I only have the Celestron f/6.3. Reproduction without permission prohibited. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions. But when not in the box or on the telescope, there is no cover for the other end. The most significant mechanical variation, however, is the quality and precision of the threading. Place the plastic covers on the lens when not in use to reduce the dust collection. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. Sign up to get exclusive deals, observing tips, and new product announcements. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. That said any comparison reviews are helpful. 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. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. Thks for that and its not for visual it for astrophotography. We process your personal data as stated in our. Focal reducers for refractors with focal ratio of f/7 to f/9, roughly, have a design reduction factor of about 0.75x to 0.8x and produce a flat field by correcting for the curvature of the objective lens. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. Brightness, color, and contrast were subtly different, but could be as much the day they were coated as any real difference in the two brands. It's important to match the back focus to within a millimeter or two to get an optimal image, especially with cameras with larger sensors. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. My application is mostly visual now, but I'm looking to do more astrophotography over time. Using one on such a scope would make demands on the eyepiece design and increase the exit pupil to an extent that focal reduction on fast Newts is not practical. For imaging, a T-adapter is threaded to the camera side of the focal reducer, which in turns connects to the camera with the appropriate hardware. Start here to find the perfect telescope for you! In such cases, we will be happy to take the item back as per our standard return terms. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Yet, the Antares still easily and fully threaded without any hitches. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. The key points are as follows: So just remember that a smaller distance (from the camera or eyepiece) means a lower amount of reduction (and vice versa). However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. 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. 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 have the Antares and am not unhappy with it, but for AP I would want more back focal distance if those numbers are accurate. No retailers currently carry this product. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. I read another thread in a different forum about F6.3 reducer correctors and one amateur posted an image about glue coming out of an astromania f6.3 reducer which he planned to return. Reducer Lens .7x - EdgeHD 1100 Learn More. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. Please Log in to save it permanently. Some are available in 1.25" barrel format but with C threads. I was referring to the C6 to answer you specifically. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. This is a. ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. InternetSales@optcorp.com, 800-483-6287 Contiguous US Customers:All items we sell ship for free within the Contiguous US. Never noticed any anomalies with this unit. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. It can also be used with any other small chip CCD camera having a 1.25" nosepiece, such as the Celestron NexImage, Meade DSI . The easiest way to use a focal reducer is to make sure you place it at the specified working distance in front of your camera or eyepiece. This article explains the basics of how focal reducers work with an astronomy telescope. The threads were similar on the eyepiece end, but a bit smoother. Given the results of Test #1, I wanted to see if there was any truth to this assumption. . which looks like the same one. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. No experience with the Antares reducers, but I haven't personally seen a difference between Celestron and my current pair of made in Japan Meade reducers. These RC reducers cannot be used with other types of telescopes. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. I doubt there is any difference between the Antares and the Celestron except price. For visual use, this means you get lower power with the same eyepiece and a wider field of view. Fumbling around in the dark, fine threads might be a problem. For Stephen Wilkerson: The ZWO ASI120MC-S does come with a wide angle lens, HOWEVER, it is NOT intended to used when you are using the ASI120 camera attached to your telescope. Copyright 2003-2022 Agena AstroProducts. These 0.63x focal reducers were originally designed to optimize for an image circle to match 36mm x 24mm film or its digital equivalent for astrophotography. In terms of reduction and correction - which are what reducer/correctors are supposed to do - both are superb. We will be glad to help. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. Download the Celestron PWI Telescope Control Software. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. Advanced designs for Schmidt-Cassegrain scopes such as the Meade ACF or Celestron Edge HD have optical elements in the tube to correct for coma and field flatness. Can these economical focal reducers from GSO and other vendors result in good images? Maybe I got a lemon. If you want to save a few buck watch the classifieds on CN. I have the Japanese version and although I haven't used it in quite awhile, the views through it were superb with no internal reflections at all. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Style: All Rights Reserved. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. This may be a problem if the focuser tube or the diagonal (for visual observing) is too narrow to accept light at this larger angle. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. As I understand it, compared to the old Meade SCT's, the ACF is already "coma corrected", so the standard Meade, Celestron etc F6.3 focal reducers are not suitable and will only worsen the images. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? 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. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads Will not focus with the stuff I have. 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. If I had to guess, the difference is maybe 10-15 grams. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. If a stronger level of focal reduction is used, say 0.5x, then the image circle may be too small to fill the sensor of larger cameras. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). SKU: CEL-94245. Very helpful, thanks a lot for this article! Wow, that is a very detailed discussion! Over the course of a several nights of general observing, I swapped back and forth between the Antares and Celestron R/Cs on a wide variety of objects open clusters, brighter galaxies, a couple of nebulae, and globular clusters as well. The female end attaches to the rear cell of the telescope. Melotte 15 - First Process in PixInsight (easy! As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. Powered by Invision Community. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. If used with other f/ratios, the field flattening characteristic may be unpredictable. Product Details 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. In both cases will end with a similar tfov. Depending on the design of the telescope, they may require separate focal reducers if they require focal reducers at all. 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). What an enjoyable read and detailed comparison. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Again, these focal reducers are often provided by the telescope manufacturer. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. When placed in the focal plane in front of a camera or eyepiece, a focal reducer leads to a wider field of view and a brighter image of extended objects, which is important for reducing the exposure times when imaging faint extended objects like nebulae or galaxies. Hence, there is a chance that you may not be able to thread your SCT diagonal or other SCT accessory on to this reducer for these or for any other brand. However, I noticed immediately that the Antares had a bit more of an heft to it, giving it a solid feel the Celestron didnt possess. However, some focal reducers can be used over a wider range of working distances, especially those with simpler optical design, and especially when used with cameras with smaller sensors. Read our 101 article or get in touch. Possibly the design of the Antares was changed .. 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. 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. If I had to chose one, I would base my decision on your level of light pollution perhaps the Antares for its slightly higher transmission if you live under less light polluted skies, but the Celestron for its greater contrast if you are dealing with a suburban or urban light dome. Things change but when I rebought I got an Antares and it seems about the same to me. The female end attaches to the rear cell of the telescope. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. It has only one cover, which surprised me. StevieDvd Members 1,182 1,812 Location: Stevenage, UK Posted March 9, 2021 (edited) Don't know but your welcome to try out my Meade 6.3 sct reducer next time you are passing. Planetarium software package which provides easy-to-understand explanations and impressive visuals of all kinds. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. At least these two units I tested make the answer - whatever. Reducer Lens .7x - EdgeHD 1100. JavaScript seems to be disabled in your browser. Check out our 2022 telescope buying guide here! We will match any online price that we confirm as valid. That's partly because focal reducers correct for field curvature, which itself depends on the focal ratio and other optical design factors of the telescope. This fully multi-coated lens provides maximum light transmission with near full-field illumination. In practice, it's important to remember that you will rarely operate at the exact working distance and at the exact reduction factor that is specified. Most reducers have a design reduction factor, MRD, that assumes the reducer is placed at a specific working distance, D, from the back surface of the focal reducer itself. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. Since the focal plane of an eyepiece is rarely precisely known(except for some brands such as Baader Planetarium and Tele Vue), and because the nosepiece of an eyepiece is of a fixed length, the actual reduction factor will be close to, but not exactly at, its designed reduction factor. ), but stars seemed a bit tighter and their colors were richer and more dramatic. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. Orders placed over the weekend will be shipped on the following Monday. Focal reducers for many SCTs and their flat-field equivalents usually have a back-focus distance of 105mm. However, this also came at a cost, as the sky background in the Antares was slightly brighter. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. Read our guide! For the best experience on our site, be sure to turn on Javascript in your browser. Wonder how they would stack up with a Japanese 6.3. I have both the Antares and the Celestron reducers. I think that the FRs made in Japan in the day may have been better. 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. The nominal design reduction factor of these reducers is typically 0.5x. Its a good thing I have the super lube handy or my neighbors wont be happy with me.come to think of it, Im sure the small mammals here wouldnt be thrilled either! Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. Fastar Technology allows imagers the option of drastically increasing the speed and sensitivity of their Celestron optical tube, allowing bright, detailed images with short exposures. No difference. Performance wise what differences might there be using the reducer on a smaller scope. Product Details. More details are found in the Appendix of this article. Not one detectable iota of discernable difference. Enter it during checkout! Some refractors such the TeleVue Nagler-Petzval (NP), the Takahashi "FSQ", and the William Optics Redcat/WhiteCat 51 have inherently flat fields because of internal optical elements. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. The designed reduction factor (0.5x in the case of the GSO reducer example above) should be considered a rule of thumb or approximate value in most cases, rather than a very precise number. 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. Start Chat 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. Who cares? More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. We do not price match competitors if they are out of stock. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. Many reducers, such as the Celestron HD focal reducer mentioned above, and many focal reducers for apochromatic refractors, are meant to be used within a few millimeters (or less) of the specified working distance to achieve the best possible image results. I am a purely visual observer, so will evaluate for visual use only. 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. I have this one Opticstar F6.3 Focal Reducer / Corrector. If the focal reducer is to be used for visual observation, the visual back is threaded onto the eyepiece side of the reducer, and then a star diagonal and eyepiece are installed as usual. What I do know is that the Antares and the Celestron samples that I have perform exactly the same from the center right out to the edges. I think there may be some confusion here, because Antares makes a variety of reducers for eyepieces and scopes in addition to this SCT R/C but this definitely is a reducer/corrector. We reserve the right to verify a competitor's advertised price and the availability of the item. This Antares 1.25" 0.5x focal reducer lens (tele-compressor) is used under the Orion brand name to thread into the nosepiece of Orion StarShoot Solar System cameras and StarShoot Deep Space Color Imaging Camera. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. It is not a corrector or flattener. It features a standard male SCT thread (2" OD, 24 TPI) on one side and a standard SCT female thread on the other. You need to be a member in order to leave a comment. The author finds differences in throughput and color balance, but then says he thinks the lenses are identical and he reaches his conclusions based on very long observing session. Some third-party vendors also make reducers for SCT scopes. They never really recovered from selling a few 15 years back with element reversed. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. 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. Focal reducers for SCT, RC, and field-flattened Edge HD or ACF telescopes thread onto the back of the telescope tube with 2"-24 or 3"-28 SCT threads. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Clearly cost is a big factor for satisfied users. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? 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. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. USD $80.00. Many Ritchey-Chretien telescopes available today are made by GSO. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. Reducer - Corrector Learn More. Does anyone have any experience with the Celestron and Antares focal reducers? a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. The lens is housed in machined aluminum for are machined aluminum black anodized. If used before or beyond the working distance, unwanted image distortion may result. Copyright 2003-2022 Agena AstroProducts. 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 example, with a 0.8x focal reducer, a telescope with a focal length of 800mm will operate at 800 x 0.8 = 640mm when the reducer is placed at the working distance specified by the manufacturer. 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). It covers the basic optics and design specifications of a focal reducer, and goes through some practical factors to consider when selecting and using a focal reducer. and you will be fine. Not a bit. I use the same back spacing for both on a small 6" Celestron SCT. . I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. Due to the design, the Reducer/Corrector lens does diminish a small amount of field curvature common to all Schmidt Cassegrain telescopes but does not eliminate it. Imagine having two telescopes in one a long focal length instrument for lunar and planetary work and a short focal length scope for deep sky observing and astrophotography. The internal surfaces are blackened and glare-threaded to provide the highest contrast. CPWI has an extensive object database, employs PointXP mount modeling, and more. Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. The most commonly available focal reducers for SCTs are the f/6.3 reducers from Celestron and a similar f/6.3 focal reducer from Meade. I wish there was. This is very impressive performance given how hard this problem is to mitigate in general. If yes, what kind of focal reducers can I use? This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors.