Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. It is not a corrector or flattener. A few large telescopes and mounts are excluded from this free shipping offer. control and Sky Viewer display makes selecting your target easy. You attach the focal reducer to the rear port on a SCT and can keep it covered. 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. CPWI has an extensive object database, employs PointXP mount modeling, and more. It is recommended for . Antares f/6.3 Focal Reducer for SCTs - Awesome Astro 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! With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. The female end attaches to the rear cell of the telescope. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. Clearly cost is a big factor for satisfied users. Nebula Filters. For the best experience on our site, be sure to turn on Javascript in your browser. The price for an item/offer must be listed and valid at the time of match. No retailers currently carry this product. No results, please adjust your filters. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. 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. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. We do not price match competitors if they are out of stock. I have the Antares and am not unhappy with it, but for AP I would want more back focal distance if those numbers are accurate. Contiguous US Customers:All items we sell ship for free within the Contiguous US. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). 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. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Sign up for OPT news, exclusive offers, and updates on the latest gear! But when not in the box or on the telescope, there is no cover for the other end. I use it on my C8 SCT with a 1000d, and it seems to do everything written on the tin. Free shipping $189.95 The most significant mechanical variation, however, is the quality and precision of the threading. Check out our 2022 telescope buying guide here! Over the course of a several nights of general observing, I swapped back and forth between the Antares and Celestron R/Cs on a wide variety of objects open clusters, brighter galaxies, a couple of nebulae, and globular clusters as well. If you want to save a few buck watch the classifieds on CN. I found both to be very good. USD $80.00. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. Celestron makes a series of focal reducers for the Edge HD line that are matched to the 8", 9.25", 11", and 14" apertures of these scopes. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Wonder how they would stack up with a Japanese 6.3. Obviously bright objects like Jupiter or The Moon show the reflections. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. One of the most important factors in a telescope is its transmissionthe percentage of light that reaches the focal plane. Increase that distance, and greater reduction results and visa versa. An image of about 24mm across, approximately, allows an observer to use a 1.25" eyepiece with a maximal field stop. 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. Reducer Lens .7x - EdgeHD 1400 Description. because they really dont matter. In this configuration, the 29.5mm camera nosepiece and a 6mm extension ring positions the reducer at a working distance of 53.5mm from the camera sensor, which is located 12.5mm inside the front edge of the camera. 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. 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. No small animals were harmed in making these observations. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. Today, our world-class team of optical and electronic engineers continues to push the boundaries of technology. Telescope Focal Reducers & Correctors - High Point Scientific Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). The Celestron f/6.3 is ~150 compared to the Antares at ~70. Using this same example of an 8" SCT and a 0.63x reducer, a visual observer can also enjoy brighter images and a wider field of view. 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. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. Housings, threads, reduction, correction, blah, blah, blah. Very helpful, thanks a lot for this article! First, let's have a look at some key optical parameters are needed to understand focal reducers. 2023 Celestron, LLC. Steve 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. Celestron's EdgeHD reducers feature a custom 5 element optical design engineered to maintain the flat-field performance of our award-winning EdgeHD optical system. This should not be the case if they have their purportedly different focal lengths. Clean, fun jokes the tradition continues - Page 106 Explore Scientific - Keys to the Universe Sale. 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. JavaScript seems to be disabled in your browser. The resultant reduction factor was measured to be 0.46x. There are also third-party vendors such as Hotech. 2023 OPT Telescopes. 800-483-6287 The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. Thanks guys, appreciate the feedback. We process your personal data as stated in our. Focal Reducer, 2", 0.7X. For the best experience on our site, be sure to turn on Javascript in your browser. In this case, an additional T-adapter (with an optical length of 50mm) is needed to get the spacing correct for a DSLR or other camera with a 55mm back focus. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). This rugged, 3-in-1 device features a true tactical 3-mode flashlight, a hand warmer, and a portable power bank for recharging your personal electronics on the go. Increasing the operating distance, that is, moving a focal reducer away from the eyepiece or camera reduces its reduction factor, or conversely increases the amount of reduction. Copyright 2003-2022 Agena AstroProducts. Try & buy if you like - usual mates rates. How about for visual observers? 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. Antares f/6.3 SCT Focal Reducer - Rother Valley Optics Ltd Meade and Celestron both sell such SCT-T adapters with the correct optical length. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. 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. 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. I've never found my 0.63 reducer causing CA when used with my SCT. When you said, "in some cases" a focal reducer also works as a flattener/corrector, are you saying that not all focal reducers are flatteners/corrector? Again, to my surprise, there was absolutely no difference between the Celestron and Antares on any star. The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). The stock Celestron visualback is just under 2 long. All Rights Reserved. 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) Share Customers Also Purchased Description if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place.