How about for visual observers? These RC reducers cannot be used with other types of telescopes. 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. No results, please adjust your filters. 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. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. Reducer Lens .7x - EdgeHD 1400 Learn More. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image.
Focal Reducers | Celestron 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. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. 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. The equations in the Appendix show how this all works. There are many different types of focal reducers and they all effect. The two samples I have PERFORM IDENTICALLY. 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. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. Focal Reducer, 2", 0.7X. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. 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. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. Once focused it's pretty good. Please re-enable javascript to access full functionality. However, this also came at a cost, as the sky background in the Antares was slightly brighter. Request stock alerts and we'll let you know when the item is back in stock. 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). Your price: $579.00. In these equations: The combined focal length of the objective and focal reducer is given by Equation 1: For example, when d1=0, that is, the focal reducer is at the focal plane of the objective, Fcomb=Fo, so the focal reducer has no effect. So it provides a 0.63x design reduction factor when used with an f/10 SCT at the specified working distance. Things change but when I rebought I got an Antares and it seems about the same to me. CPWI has an extensive object database, employs PointXP mount modeling, and more.
Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes - Agena Astro Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. However, in principle, the reduction factor of a focal reducer can be varied by changing the distance from the back of the focal reducer to the camera or eyepiece. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! 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. All rights reserved. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). This is a. If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. First, let's have a look at some key optical parameters are needed to understand focal reducers. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. Very helpful, thanks a lot for this article! Reproduction without permission prohibited. But I am rusty, can you condense a bit for me please? Never noticed any anomalies with this unit. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. The lens has a knurled surface, providing a tremendous gripping surface for threading/unthreading.
Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. The female end attaches to the rear cell of the telescope. Celestron or Antares? 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. You currently have javascript disabled. Steve Much to my surprise, swapping back and forth between the two correctors using all three diagonal configurations, I also could detect absolutely no change in reduction between the two reducers. 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 doubt there is any difference between the Antares and the Celestron except price. The review is a subjective visual impression, which is interesting but not best evidence. 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). How does it look thats what matters. I was originally hoping to do this with a made in Japan Celestron, but ended up with a newer China version but thats probably better in the end since it is the version now available, with the Japan ones rarer and only available used. Observing the microscopic world has never been easier! I have the Antares and have no complaints. Because most modern Newtonians already have relatively fast focal ratios, these telescopes do not usually use focal reducers. 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. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. If I had to go out on a very thick limb, I would have to say that these two reducers/correctors are, indeed, identical the exact same glass in slightly different housings with different lettering. 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. 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.
Antares f/6.3 SCT Focal Reducer - Rother Valley Optics Ltd For this shoot-out, I used a standard Celestron C8 with Starbright coatings. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; The nominal design reduction factor of these reducers is typically 0.5x. With the barrel 1.25 reducer won't focus, all I get is fuzzy snowballs. Perfect for the serious student, professional scientist and discriminating hobbyist. 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! Sharpness is essentially the same. We will be glad to help. 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. 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've never found my 0.63 reducer causing CA when used with my SCT. Most amateur astronomers are familiar with a Barlow lens (or a focal extender), a negative or diverging lens that effectively increases the focal length and the focal ratio of a telescope's objective lens. Reducer Lens .7x - EdgeHD 925 Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? Nada. Hello! Copyright 2003-2022 Agena AstroProducts. Meade once made an f/3.3 focal reducer for SCT scopes. Also read the reviews here, including those at 4 stars. For the best experience on our site, be sure to turn on Javascript in your browser. None of this was offensive, nor did it interfere with views in any significant way. 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. It has only one cover, which surprised me. 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. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor.
F 6.3 focal reducer/corrector. - Discussions - Stargazers Lounge The click-lock with a 2 dielectric diagonal with a somewhat shorter light path, using both a 2 ES 28mm/68 and the same low-profile adapter with a 1.25 ES 24mm/68. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. 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. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. 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. 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. Start Chat This innovative software solves the time-consuming problem of trying to pinpoint the North Celestial Pole. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. But while the image gets brighter, the size of the image circle gets proportionately smaller. No retailers currently carry this product. Stars had a tiny bit more sparkle and pop. Check out our 2022 telescope buying guide here! . They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. Never used one, but read the reviews here that suggest a coating problem. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. 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. That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. 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. Try & buy if you like - usual mates rates. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. 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 me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. The stock Celestron visualback is just under 2 long. I use the Celestron version and it seems OK for both visual and imaging. We have placed cookies on your device to help make this website better. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. 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. All additional accessories mount onto the exterior/male threads. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. 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. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. 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. Is that distance D= Fo-d1=Fo-(d2/MR)? Enter it during checkout! This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. 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. 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. 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 Reducers - Complete Overview and Function - YouTube 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. Some coma is visible in the corners, but the image is quite good for EAA applications. Images made with my ZWO 533 camera testing both show them to be essentially the same. During a twenty-year scientific career, he developed laser systems to detect molecules found in interstellar space and planetary atmospheres, and leveraged his expertise to create laser technology for optical communications networks. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. 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. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Housings, threads, reduction, correction, blah, blah, blah. 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. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. 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. The focal length and design working distance for this focal reducer were not available from the manufacturer. The Buyer's Guide To Eyepieces at the top of the Eyepieces forum has a column for this spec. Unique focal reducer and field corrector lens accessory, Reduces the focal length and f/ ratio of your Schmidt-Cassegrain telescope by 37%, Provides a dual focal ratio instrument, without sacrificing image quality, Compatible with all Schmidt-Cassegrain telescopes (see compatible list in description). Obviously bright objects like Jupiter or The Moon show the reflections. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. The reducer fits all Meade and Celestron . 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. Your mileage may vary. I own both and concur heartily. Many Ritchey-Chretien telescopes available today are made by GSO. Brian Ventrudo is a writer, scientist, and astronomy educator. Increase that distance, and greater reduction results and visa versa. However, these will not impact optical performance. By using this site, you agree to our Terms of Use. 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. ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration. 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. However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. 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. At least these two units I tested make the answer - whatever. High power views will provide flatter fields all the way to the edge, both visually and photographically. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. An image of about 24mm across, approximately, allows an observer to use a 1.25" eyepiece with a maximal field stop. 3. These reducers have a back focus (or design working distance) of 80mm. 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 faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. 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. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. Copyright 2003-2022 Agena AstroProducts. Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. An f/6.3 reducer is designed to reduce the focal ratio of an f/10 SCT to f/6.3. The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). Benefits limited to hardware and conditions? I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. 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 imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. Fumbling around in the dark, fine threads might be a problem. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Completely stuck, completely frustrated. 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%. Hmmm .
Watch this before you buy Celestron 8SE SCT, or a Focal Reducer or a 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. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. Who cares? They never really recovered from selling a few 15 years back with element reversed. 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.
Reducer Lens .7x - EdgeHD 1100 - Celestron I was referring to the C6 to answer you specifically. 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. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. Right off the bat, I was struck by how similar the two R/Cs were. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. 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). There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). 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.
Celestron & Antares f/6.3 Reducer/Corrector Shoot-out And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Again, these focal reducers are often provided by the telescope manufacturer. I'd favor the Japanese Celestron version over the others that are commercially available. You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. They are reported as identical. CPWI has an extensive object database, employs PointXP mount modeling, and more.