Just one question. The threads were similar on the eyepiece end, but a bit smoother. For the best experience on our site, be sure to turn on Javascript in your browser. Weasner's Meade and Antares Focal Reducers Review Not noticed any optical problems. 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. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. The reducer fits all Meade and Celestron . Focal reducer for 8SE - Celestron vs. Antares - Cloudy Nights OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! How does it look thats what matters. It is recommended for . Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. You need to be a member in order to leave a comment. Thanks for pointing this out. These reducers have a back focus (or design working distance) of 80mm. Quite interestingly it bears the very same engravings of the Meade 4000 r/c (including "series 4000") except for "MEADE". It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. It's easy! 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. Well done. 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). Never noticed any anomalies with this unit. Because I have not heard any complaints about the made in China R/C. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. With the Celestron Reducer/Corrector Lens, thats precisely what you get. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. Most refractor manufacturers such as William Optics, Tele Vue Optics, Explore Scientific, Sky-Watcher, William Optics, and Stellarvue make their own focal reducers optimized for use with their telescopes. Hello! Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. You attach the focal reducer to the rear port on a SCT and can keep it covered. For imagers using longer focal-length refractors and SCTs, especially when using smaller sensors that place less demand on the focal reducer, there are economical alternatives for focal reducers from manufacturers such as GSO, Agena, and Antares. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. Antares F/6.3 SCT Focal Reducer | OPT Telescopes For the best experience on our site, be sure to turn on Javascript in your browser. Get ready for a night of astroimaging with your mount faster than previously thought possible with All-Star Polar Alignment. I own both and concur heartily. I am a purely visual observer, so will evaluate for visual use only. They never really recovered from selling a few 15 years back with element reversed. I have an 8SE, and am thinking about getting a focal reducer. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. Not one detectable iota of discernable difference. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. 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. With the barrel 1.25 reducer won't focus, all I get is fuzzy snowballs. However, even though the imprint on the item states "Reducer / Corrector" please note that his is a reducer only. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. 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. 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. Yet, the Antares still easily and fully threaded without any hitches. Description. They are reported as identical. My Celestron was made in China and the Antares in Canada. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. This is very impressive performance given how hard this problem is to mitigate in general. ED stands for "extra-low dispersion," which refers to the composition and optical properties of the glass used for the lenses. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). I have the Antares and have no complaints. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. Maybe I got a lemon. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. 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. 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. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. Orders placed over the weekend will be shipped on the following Monday. It was used strictly for imaging, not visual observing. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Download the Celestron PWI Telescope Control Software. The two samples I have PERFORM IDENTICALLY. Contiguous US Customers:All items we sell ship for free within the Contiguous US. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. How to Set the Correct Back Focus for Your Telescope (Guide) Celestron Reducer Lens .7x - EdgeHD 925 The EdgeHD .7x Focal Reducer Lens makes your EdgeHD 925 one full F-Stop faster than f/10, reducing your exposure time by half to capture the same brightness of object 5-element lens design Maintains similar. Antares Click Lock Visual Back - Cats & Casses - Cloudy Nights For this shoot-out, I used a standard Celestron C8 with Starbright coatings. Nada. Wow, that is a very detailed discussion! 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. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. Not a bit. I have this one Opticstar F6.3 Focal Reducer / Corrector. If you are using a camera that has a back focus of less than 55mm, additional spacer rings will be required between the reducer and the camera. Sharpness is essentially the same. In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. Our proprietary StarBright XLT optical coatings dramatically increase transmission, up to 97.4% on our Schmidt corrector lenses. The Celestron f/6.3 is ~150 compared to the Antares at ~70. 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. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. 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. What is likely is that fatigue sets in, and also that as the targets move toward or a way from the meridian there will be changes for that reason alone. Turn it on and push Align. In about three minutes, youre ready to observe! 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. 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. Reducer Lens .7x - EdgeHD 925 Learn More. Housings, threads, reduction, correction, blah, blah, blah. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. It's usually specified in millimeters. 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). With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. We tested GSO's 1.25" 0.5x focal reducer at a variety of operating distances and calculated the field of view through a telescope to derive the actual reduction factor that is plotted below. Despite never removing it no matter what I was looking at. 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. Reproduction without permission prohibited. 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. Sign up for OPT news, exclusive offers, and updates on the latest gear! At least these two units I tested make the answer - whatever. What an enjoyable read and detailed comparison. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. 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. Possibly the design of the Antares was changed .. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer. Celestron or Antares? Once focused it's pretty good. Images in the Celestron tended to appear ever-so-slightly dimmer (maybe? It works fine but you should stick with 1.25 EPs; or can use 2" EPs without corrector. Here, there was a subtle difference . A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. 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%. Steve . CEL-94245. First, I wanted to compare the actual reduction provided by these competitors, as many threads here cite different ideal spacing from the reducer to eyepiece focal plane to achieve the correct f/6.3 result. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. Focal reducers for refractors are easy to use. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. 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. However, these will not impact optical performance. I've never found my 0.63 reducer causing CA when used with my SCT. - thanks. Regardless, the difference was miniscule and is more than adequate on both and exceeds a 8 or 6 SCTs baffle tube diameter. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. 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 would not use the reducer with a 2" diagonal or eyepiece in the C6. Focal Reducer for SCT - ACF - Stargazers Lounge This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. Antares f/6.3 Focal Reducer for SCTs - Awesome Astro 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. 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. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. SKU: CEL-94245. 1.2" in that scope is a field stop of 43mm at f/10 and 27mm at f/6.3. By 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. Agena's Guide to Focal Reducers - Agena Astro 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. This is a. 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. and you will be fine. Most Feather Touch focusers cost between $300-$350. 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. Please let us know what topics you are interested in. 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. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. If yes, what kind of focal reducers can I use? There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. Reducer - Corrector Learn More. During checkout, you may also be shown other optional faster shipping choices.US Customers in Hawaii and Alaska: Free shipping applies to almost all products. Antares f/6.3 SCT Focal Reducer - Rother Valley Optics Ltd Reducer Lens .7x - EdgeHD 800 3. The working distance or required back focus, explained above, is usually specified and is far more important in practice. Thks for that and its not for visual it for astrophotography. Reducer Lens .7x - EdgeHD 1100 - Celestron I think that the FRs made in Japan in the day may have been better. As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. The female end attaches to the rear cell of the telescope. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. 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. Copyright 2021 Stargazers Lounge When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. Explore Scientific Keys to the Universe Sale. CPWI has an extensive object database, employs PointXP mount modeling, and more. No results, please adjust your filters. 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. Can these economical focal reducers from GSO and other vendors result in good images? 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.