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Normal shipments will resume on Monday, March 6, 2023. nleash the full pointing accuracy of your Celestron computerized telescope with a specialized telescope control software suite. That was fun. Copyright 2003-2022 Agena AstroProducts. 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. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. 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 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. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; Powered by Invision Community. 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. 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. 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. These reducers have a back focus (or design working distance) of 80mm. During check-out, you will be presented with several shipping choices and costs. A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. Housings, threads, reduction, correction, blah, blah, blah. 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to the design reduction factor MRD: Equations (6) and (7) imply these important considerations: Most manufacturers do not publish the focal length of their focal reducers, so it is not usually possible to calculate the working distance and design reduction factor. 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. 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. Increase that distance, and greater reduction results and visa versa. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. 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. All Rights Reserved. For example, the focal reducer for an 8-inch Celestron EdgeHD telescope has a design reduction factor of 0.7x and a specified working distance (or back focus) of 105mm. I wont bother with differences in packaging, caps, etc. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.International Customers:Free shipping does not apply to international orders. 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. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. I've looked through one from Meade and first impression was that it was like the Celestron version. 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. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. This focal reducer from Celestron reduces the effective focal length by 0.63X Enjoy the wider field of view & faster exposure times at f/6.3 with f/10 telescopes f/11 telescopes, such as the C14 will perform at f/7 The Celestron f/6.3 Reducer has four fully-multicoated elements Reduce your exposure times by a factor of 3! This filter threads on to the rear cell of your Celestron or Meade SCT telescope. By Bear in mind you can't squeeze blood out of a turnip, i.e. On the trail, at the job site, in the classroom, or simply sitting at home relaxing the Celestron Elements ThermoTank 3 will keep your hands toasty. 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. 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. ED stands for "extra-low dispersion," which refers to the composition and optical properties of the glass used for the lenses. Thanks. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. With the Celestron Reducer/Corrector Lens, thats precisely what you get. However, this also came at a cost, as the sky background in the Antares was slightly brighter. My experience is that CN sellers are way above those listing elsewhere. Hmmm . It has only one cover, which surprised me. My application is mostly visual now, but I'm looking to do more astrophotography over time. Hello! Does anyone have any experience with the Celestron and Antares focal reducers? There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. What an enjoyable read and detailed comparison. 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. 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. Planetarium software package which provides easy-to-understand explanations and impressive visuals of all kinds. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. 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"). The brightness, shape, and distortion of specific stars in the exact same position at the edge of the field was precisely identical in both reducers. Theres a long-running debate in these forums and even statements from some reputable dealers that the Antares is just a reducer (even though it is labeled Reducer/Corrector), whereas the Celestron is a true R/C, which flattens the SCTs naturally curved field and provides some edge correction. 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. We process your personal data as stated in our. Enter it during checkout! Field stop diameters are one of the specified specs of eyepieces. 3. No results, please adjust your filters. This fully multi-coated lens provides maximum light transmission with near full-field illumination. As one increases, the other decreases. Your price: $579.00. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. 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. I only have the Celestron f/6.3. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. 2. I focus using a moonlight electronic focuser and focusmax. 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. No negative issues to report. 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. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. Nada. Steve The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? Celestrons aplanatic EdgeHD optics revolutionized astroimaging. 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. 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. High power views will provide flatter fields all the way to the edge, both visually and photographically. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. 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. They never really recovered from selling a few 15 years back with element reversed. If used with other f/ratios, the field flattening characteristic may be unpredictable. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. If you want to save a few buck watch the classifieds on CN. Turn it on and push Align. In about three minutes, youre ready to observe! More about this below. The previous post shows the reducer on what appear to be two different refractors. But while the image gets brighter, the size of the image circle gets proportionately smaller. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. For visual use, this means you get lower power with the same eyepiece and a wider field of view. 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. I was referring to the C6 to answer you specifically. How about for visual observers? For the best experience on our site, be sure to turn on Javascript in your browser. They are also less expensive than many external focusers of similar build quality. But I am rusty, can you condense a bit for me please? Please Log in to save it permanently. 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. Some coma is visible in the corners, but the image is quite good for EAA applications. 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. Melotte 15 - First Process in PixInsight (easy! Well done. 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. 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. However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. Performance wise what differences might there be using the reducer on a smaller scope. 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. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. Sign up to get exclusive deals, observing tips, and new product announcements. The internal surfaces are blackened and glare-threaded to provide the highest contrast. I have had the Japan unit on the back of my C5 since 1994 or thereabouts. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? We will match any online price that we confirm as valid. I own both and concur heartily. You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. Product Details. The design reduction factor of a focal reducer is the relative amount by which the effective focal length of the telescope is reduced when the focal reducer is used at its specified working distance or back focus. 3. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. The female end attaches to the rear cell of the telescope. The resultant reduction factor was measured to be 0.46x. F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. Please note, orders placed after 10am on 2/28/2023 will be delayed. Take control of your telescope! Many Ritchey-Chretien telescopes available today are made by GSO. Specially-designed focal reducers are available for use with these telescopes. There are also third-party vendors such as Hotech. InternetSales@optcorp.com, 800-483-6287 For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. Copyright 2003-2022 Agena AstroProducts. Maybe I got a lemon. 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. 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. If yes, what kind of focal reducers can I use? Several functions may not work. However, these will not impact optical performance. M44 was a perfect target for this, as its large size maxes out the FOV on a C8 with a corrector, and its bright stars make great targets for measuring the very edge of the visible field. It is recommended for . 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. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. Please let us know what topics you are interested in. We do not price match competitors if they are out of stock. 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. 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. I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. There is a way to make subjective data more useful and that way is proper blind, or better still. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. Read our 101 article or get in touch. . If I had to guess, the difference is maybe 10-15 grams. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Reproduction without permission prohibited. It might work but it does not tell us anything about how well or to what extent the product works to correct the field of an SCT. The lens is housed in machined aluminum for are machined aluminum black anodized. Reducer Lens .7x - EdgeHD 800 Some manufacturers will specify the working distance from the middle of the rear lens surface, and this number must then be converted into a practical working distance number by subtracting the amount by which the rear lens surface is recessed in its housing. I'm going with the Celestron. Contiguous US Customers:All items we sell ship for free within the Contiguous US. I wish there was. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. Despite never removing it no matter what I was looking at. control and Sky Viewer display makes selecting your target easy. For the best experience on our site, be sure to turn on Javascript in your browser. looks virtually identical, except for the lettering. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. Add a 0.63x reducer, and the brightness of extended objects increases by (1/0.63)2 = 2.5. Reducer Lens .7x - EdgeHD 1400 As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. 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. If you do so, you will achieve the design reduction factor. None of this was offensive, nor did it interfere with views in any significant way. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). CEL-94245. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. It was used strictly for imaging, not visual observing. Benefits limited to hardware and conditions? 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. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. A few large telescopes and mounts are excluded from this free shipping offer. Because I have not heard any complaints about the made in China R/C. ), 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. You currently have javascript disabled. 2023 OPT Telescopes. 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. Start here to find the perfect telescope for you! This would tell us exactly how well aberrations are corrected. 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. Thanks guys, appreciate the feedback. I've only used it a few times but it looks good to me. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. The reducer fits all Meade and Celestron . I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. With the barrel 1.25 reducer won't focus, all I get is fuzzy snowballs. This standard distance is a consequence of the design of DSLR cameras for which the distance of the sensor to the outer edge of the flanges is about 45 mm, while the T-ring that attaches to the flange for astrophotography is about 10mm thick. 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. Again, swapping back and forth for a couple of hours on M44, M35, and several brighter stars, I examined the shape of specific stars near the edge of the field with both correctors. Thanks for the extremely valuable article. Here, there was a subtle difference . 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. Read our guide! The price for an item/offer must be listed and valid at the time of match. Newtonian reflectors will seldom be able to accommodate the in-focus travel demanded by focal reducers. With this telescope and this focal reducer, it does not help to move to a 2" eyepiece and a 2" diagonal as the visual view will be akin to looking through a porthole within the larger apparent field of view of the eyepiece. They are reported as identical. The amount of reduction is simply the percentage by which a reducer shortens the effective focal length of a telescope and is calculated as (1 Reduction Factor) x 100%. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! On the camera side, the focal reducer has male M42x0.75 or M48x0.75 threads that attach directly to the T-ring (with an M42-M48 adapter if necessary). All Rights Reserved. Try & buy if you like - usual mates rates. 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. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. 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. Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. I am new to these optic topics, and I want to ask you what happens with Masutov like SW or Celestron 4 or 7 inches. Photographically you also get a wider field and much shorter exposures. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. Focal Reducer, 2", 0.7X. This should not be the case if they have their purportedly different focal lengths. Reducer Lens .7x - EdgeHD 925 Learn More. Using an eyepiece with a 27mm field stop with the reducer will illuminate the edge the same as using an eyepieces with a 42.9mm field stop without it. Focus misses by about 1 turnof the focus knob.Here is my solution:Buy a shorter 1.25 visual back for my scope. The equations in the Appendix show how this all works. In both cases will end with a similar tfov. Style: Oceanside Photo & Telescope wants our customers to shop with confidence knowing that you will always get the best deal available. Article Agena AstroProducts, 2019. Meade does not make an equivalent line of focal reducers for the ACF scopes, although some models of Meade ACF are already at f/8, faster than the f/10 ratio of Celestron Edge HD scopes. If used before or beyond the working distance, unwanted image distortion may result. 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. 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. 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. 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. Equation (4) shows the relationship between the distance d2 and the reduction factor MR. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads 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. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. Is that distance D= Fo-d1=Fo-(d2/MR)? Reducer - Corrector With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. 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. That means the base of the mounting threads of the focal reducer needs to be 55mm from the camera sensor to achieve the design reduction factor, which is usually 0.8x or 0.85x.