However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. Hmmm . So, this past week I challenged the Antares and Celestron models to a head-to-hear on my C8 on some decent nights of good seeing and transparency in my Bortle 5-6 urban skies. . All Rights Reserved. Each focal reducer has a fixed specification called the working distance or required back focus. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Despite never removing it no matter what I was looking at. Just one question. Steve These scopes are compatibles with focal reducers. 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. 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. 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. 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. In every configuration, there were essentially parfocal, requiring only a tiny fine focus adjustment when changing correctors. Celestron Solar Safe filter technology is GUARANTEED SAFE for direct solar observation and has been independently tested by SAI Global Assurance Services. 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). Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. Most focal reducers are designed to operate optimally at the working distance in the optical path to achieve their specified reduction factor, which is usually between 0.5x and 0.8x. 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. 2023 Celestron, LLC. You currently have javascript disabled. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). Community Forum Software by IP.BoardLicensed to: Cloudy Nights, E of San Francisco Bay and W of the Awahnee, This is not recommended for shared computers, reviews here that suggest a coating problem, Back to Celestron Computerized Telescopes, Looking for advice on first refractor and camera. Hi - most interesting - may I ask .. the brighter guys - "if a camera sensor is too small for a n adaper, will a focal reduer allow me to get greater use from the camera? Our patented SkyAlign alignment technology makes setting up a computerized telescope simple, fast, and accurate. We have tested our current batch and it works with Meade, Celestron, and Baader SCT accessories. 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 equations in the Appendix show how this all works. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. Description. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. Your eyepieces are the first accessories you should learn to use with your telescope. 3. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. Some are available in 1.25" barrel format but with C threads. Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. It is recommended for . Perfect for the serious student, professional scientist and discriminating hobbyist. I have Hirsch focal reducer, which is yet another clone of the Celestron reducer. Like you, I am primarily visually observing but I have everything together now that so I am going to start experimenting with photography so we'll see how it does there. 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. 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. I have the Antares and have no complaints. No negative issues to report. The Reducer/Corrector can also be used for terrestrial digiscoping. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. They are also less expensive than many external focusers of similar build quality. 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. More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. Orders placed over the weekend will be shipped on the following Monday. He received his first telescope at the age of 5 and completed his first university course in astronomy at the age of 12, eventually receiving a master's degree in the subject. Blue Fireball M42 T/T2 Thread Camera Adapter for Prime Focus Photography - 2" # P-06, Celestron T-Ring for Canon EOS Camera # 93419, GSO 2" Crayford Focuser for SCTs - Dual Speed, Length of male SCT thread = 5mm (0.2") but this is preceded by an unthreaded part on the eyepiece side making the total length = 8.8mm (0.35"), Length of female SCT thread = 7.5mm (0.3"). We do not price match competitors if they are out of stock. 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. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Can these economical focal reducers from GSO and other vendors result in good images? Sign up for OPT news, exclusive offers, and updates on the latest gear! Celestrons aplanatic EdgeHD optics revolutionized astroimaging. 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. So, if you have a filter that is 3mm thick, you need to add 1mm of spacing to your imaging train to retain the correct back focus. However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. 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. InternetSales@optcorp.com, 800-483-6287 Observing the microscopic world has never been easier! The more focal reduction, the further inward the focal plane will be. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. Reducer Lens .7x - EdgeHD 1100. The Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes is a low-price option for reducing the focal length of your Schmidt-Cassegrain telescope from f/10 to f/6.3. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. 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. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. This is one of our best-selling items, and customers have reported that this product is at least as good as, and probably better than, other leading f/6.3 focal reducers sold on the market for a lot more. 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 cannot, for example, use a 0.63x focal reducer intended for a standard Celestron or Meade SCT and use it on a Celestron Edge HD or a Meade ACF. 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. Getting the proper back-focus for your imaging camera is a vital step in getting the best data possible out of your telescope imaging/research rig. This article explains the basics of how focal reducers work with an astronomy telescope. For visual use, this means you get lower power with the same eyepiece and a wider field of view. 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. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. It's usually specified from the base of the mounting threads on the reducer's housing, and this is the most practical way of providing this specification. Focal Reducer, 2", 0.7X. While most Barlow lenses and focal extenders work with most kinds of telescopes available to amateur astronomers, focal reducers are designed to work in a narrow range of focal ratios of a telescope objective. I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. Because of their distinct optical design, slower Schmidt-Cassegrain telescopes (SCT) with focal ratios of f/10 require a different design of focal reducer compared to refractors. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA, Availability: Item has been discontinued by Agena and we no longer carry this item. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. Planetarium software package which provides easy-to-understand explanations and impressive visuals of all kinds. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. The female end attaches to the rear cell of the telescope. 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. Images made with my ZWO 533 camera testing both show them to be essentially the same. As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. Increase that distance, and greater reduction results and visa versa. In both cases will end with a similar tfov. Yellow and orange members of open clusters stood out a bit more as the various stars displayed their individuality. And, the reality is that every F/6.3 RC out there Celestron, Hirsch, Astromania, etc., etc. Because I have not heard any complaints about the made in China R/C. Your wishlist has been temporarily saved. Performance wise what differences might there be using the reducer on a smaller scope. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. Benefits limited to hardware and conditions? The visual back must be removed first. 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. Explore Scientific - Keys to the Universe Sale. 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. Try & buy if you like - usual mates rates. At least these two units I tested make the answer - whatever. Given past experience with them, I decided not to include the Meade version in my little experiment, as I have never met one I liked from getting one of the too-short focal length models, to one with some overflow cement in the doublet, to focus difficulties with some eyepieces. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. The distance d2, which measures the position of the new focal plane of the objective from the back of the focal reducer is given by Equation 5: In these equations, d1, d2, and MR are all variables that depend on each other through Equations 2 and 4. Housings, threads, reduction, correction, blah, blah, blah. You attach the focal reducer to the rear port on a SCT and can keep it covered. 800-483-6287 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. That was fun. The f/6.3 reducer is operating at f/5-f/5.5 with a 2" diagonal, depending on the back focus length of the diagonal. 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. Great report and verifies what I had thought all along, Fortunately, my neighbors are not out in their backyards at 11 pm, or they may have thought I was torturing a small mammal. It's highly unlikely that they could be so precisely identical unless they were. Quite interestingly it bears the very same engravings of the Meade 4000 r/c (including "series 4000") except for "MEADE". The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. 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. Will not focus with the stuff I have. Thanks guys, I'm trying to get my ZWO ASI120MC-S to work with my 90mm Meade. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). And when d1 = FR, that is, when the focal reducer is placed at a distance from the focal plane of the objective that's equal to the reducer's focal length, the focal length of the combined optical system is Fo, so it acts as a 0.5x reducer. I only have the Celestron f/6.3. It's usually specified in millimeters. 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. Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. No small animals were harmed in making these observations. I'd favor the Japanese Celestron version over the others that are commercially available. The Reduction Factor and the Amount of Reduction are inversely related. For the best experience on our site, be sure to turn on Javascript in your browser. But I am rusty, can you condense a bit for me please? Completely stuck, completely frustrated. I would pay slightly more for the Japan produced version, just because Hirsch was not bad either but sold it since I had 2 already. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. That said any comparison reviews are helpful. From the SkyProdigy, a telescope so smart it can align itself, to our high-performance EdgeHD optical system, weve revolutionized the hobby of astronomy for beginners and advanced amateurs alike. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Article Agena AstroProducts, 2019. In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? October 11, 2010 in Discussions - Scopes / Whole setups. You need to be a member in order to leave a comment. By Most Feather Touch focusers cost between $300-$350. USD $80.00. Reducer Lens .7x - EdgeHD 925 Your mileage may vary. My application is mostly visual now, but I'm looking to do more astrophotography over time. I would not use the reducer with a 2" diagonal or eyepiece in the C6. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. I found both to be very good. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. 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. Meade and Celestron both sell such SCT-T adapters with the correct optical length. There are also third-party vendors such as Hotech. Still not sure what is the right gear for you? There are many different types of focal reducers and they all effect. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. This is especially true when these reducers are used with cameras with smaller sensors with a dimension of about 1/4 to 1/3 the diameter of the reducer, and with telescopes with a focal ratio of f/7 or larger. More about this below. For this test, I used a single configuration R/C, Click-lock, and 1.25 diagonal with the adapter. Generally, views through the Antares seemed a little more transparent and brighter. I wont bother with differences in packaging, caps, etc. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. Contiguous US Customers:All items we sell ship for free within the Contiguous US. 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. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Nebula Filters. Watch this before you buy Celestron 8SE SCT, or a Focal Reducer or a Hyperstar 7,758 views Mar 28, 2018 145 Dislike Share Ray's Astrophotography 42.3K subscribers Note: I am not paid or. The lens is housed in machined aluminum for are machined aluminum black anodized. All additional accessories mount onto the exterior/male threads. I have/had both the Celestron (Japan) and Antares units. This article explained the basics of how focal reducers work with various kinds of telescopes and how their working distance affects their reduction factor, and it provided sufficient detail to help amateur astronomer choose and use the right focal reducer for a particular application. Your price: $579.00. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. We reserve the right to verify a competitor's advertised price and the availability of the item. It works fine but you should stick with 1.25 EPs; or can use 2" EPs without corrector. Antares or Celestron? 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. The naming convention of SCT focal reducers is a little confusing. 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. More details are found in the Appendix of this article. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). It must be in stock at the time of Price Match for us to make a guarantee. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. Using these numbers in equation 4 in the Appendix, below, we can easily calculate that the focal length of this unit is approximately103mm (it will be 103mm plus the small amount by which the rear lens surface of the reducer is recessed beneath the reducer housing). The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. Thanks. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. Based on Test 1 and Test 2, I think there is perhaps more validity to opposing statements here in these forums that the Antares and current China-made Celestron do, indeed, have exactly the same optics just with different housings and branding. 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. Practical Considerations of Focal Reducers, 4.2 Back Focus Requirements of Focal Reducers, GSO makes focal reducers for their line of Ritchey-Chretien, Celestron makes a series of focal reducers for the Edge HD line, 0.75x focal reducers for these telescopes, focal reducer for an 8-inch Celestron EdgeHD, A Primer on T-Rings and T-Adapters for Astronomy and Astrophotography, Choosing the Best Telescope for Beginners 2023, Top Night Sky & Astronomy Events in August 2022, Top Night Sky & Astronomy Events in July 2022, Selecting a Baader Planetarium Star Diagonal, A Guide to Choosing Astronomy Eyepieces for Binoviewers, Choosing a Magnifying Finder Scope for Your Telescope, A focal reducer will provide its design reduction factor only when it is placed at the exact working distance from the focal plane of the eyepiece or camera, Reducing the operating distance, that is, moving a focal reducer closer to the eyepiece or camera increases its reduction factor, or conversely reduces the amount of focal reduction. Antares Click Lock Visual Back - posted in Cats & Casses: Here is the situation:I bought a Celestron CPC 1100 for visual use.Want to put on the scope simulteanously a6.3 focal reducer, filter wheel, and aneyepiece turret. 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. 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. All Rights Reserved. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. Sharpness is essentially the same. Please Log in to save it permanently. Start Chat I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. 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. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. GSO, for example, has a 0.75x reducer for RC scopes with a back focus of 80mm, which is usually enough room for a wide range of astronomy cameras and accessories and spacers as needed. 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). All rights reserved. If it's positioned further from the eyepiece or camera and closer to the telescope objective, the reduction factor increases. Sign up to get exclusive deals, observing tips, and new product announcements. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Explore Scientific Keys to the Universe Sale, Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes, Skip to the beginning of the images gallery.