He tested this on an 8 Celestron , I have a Celestron 6SE. It's important to match the back focus to within a millimeter or two to get an optimal image, especially with cameras with larger sensors. There are many different types of focal reducers and they all effect. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. The review is a subjective visual impression, which is interesting but not best evidence. Sharpness is essentially the same. So it provides a 0.63x design reduction factor when used with an f/10 SCT at the specified working distance. You attach the focal reducer to the rear port on a SCT and can keep it covered. Benefits limited to hardware and conditions? Just one question. 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. The stars at the edge could be worse or better. Thanks Peter! CPWI has an extensive object database, employs PointXP mount modeling, and more. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. Focus misses by about 1 turnof the focus knob.Here is my solution:Buy a shorter 1.25 visual back for my scope. Most manufacturers provide this specification. Reducer Lens .7x - EdgeHD 800 Not noticed any optical problems. I have both the Antares and the Celestron reducers. 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. Thanks. Our patented SkyAlign alignment technology makes setting up a computerized telescope simple, fast, and accurate. Generally, views through the Antares seemed a little more transparent and brighter. How to Set the Correct Back Focus for Your Telescope (Guide) 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. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. All rights reserved. Reducer - Corrector Learn More. There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). JavaScript seems to be disabled in your browser. Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes - Agena Astro Some are available in 1.25" barrel format but with C threads. However, this also came at a cost, as the sky background in the Antares was slightly brighter. I think that the FRs made in Japan in the day may have been better. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. 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. 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. Figure 7 shows an example of an image of the Dumbbell Nebula taken with a 1.25" GSO focal reducer at a reduction factor of 0.63x with an 85mm f/7 refractor and a QHY5III-290M camera with a sensor with a 6.4mm diagonal. Take control of your telescope! The Antares focal reducer comes in small box. No retailers currently carry this product. 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. Stars had a tiny bit more sparkle and pop. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. This would tell us exactly how well aberrations are corrected. It is not a corrector or flattener. 0.5X focal reducer for Celestron, Meade, and Orion CCD imaging cameras Very helpful, thanks a lot for this article! 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 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. Check out our 2022 telescope buying guide here! Meade and Celestron both sell such SCT-T adapters with the correct optical length. Celestron Solar Safe filter technology is GUARANTEED SAFE for direct solar observation and has been independently tested by SAI Global Assurance Services. 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. To test this, I used three set-ups: 1. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet. Again, these focal reducers are often provided by the telescope manufacturer. USD $80.00. 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. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. 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. Many reducers, such as the Celestron HD focal reducer mentioned above, and many focal reducers for apochromatic refractors, are meant to be used within a few millimeters (or less) of the specified working distance to achieve the best possible image results. It was used strictly for imaging, not visual observing. Right off the bat, I was struck by how similar the two R/Cs were. I use the same back spacing for both on a small 6" Celestron SCT. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. By using this site, you agree to our Terms of Use. Just point the telescope at any three bright objectsstars, bright planets, or even the Moonand your telescope can orient itself with the night sky. Bear in mind you can't squeeze blood out of a turnip, i.e. 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. I own both and concur heartily. How does it look thats what matters. Please re-enable javascript to access full functionality. Your mileage may vary. 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. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. High power views will provide flatter fields all the way to the edge, both visually and photographically. The Best Dedicated Astronomy Cameras for Beginners, Astronomik OIII 12nm CCD Filter - T-Threads, Pegasus Astro Dual Motor Focus Controller, 10 Micron 12kg (26.45lbs) Stainless Steel Counterweight- GM 2000, I would like more information regarding stock availability dates. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. Some third-party vendors also make reducers for SCT scopes. 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. Completely stuck, completely frustrated. Most Feather Touch focusers cost between $300-$350. The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. We have placed cookies on your device to help make this website better. ), 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. However, even though the imprint on the item states "Reducer / Corrector" please note that his is a reducer only. Overall, this reducer does a phenomenal job at preventing gradients due to internal reflections from the camera sensor back to the glass in the reducer, as I suffered with the Antares reducer. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. The female end attaches to the rear cell of the telescope. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Because I have not heard any complaints about the made in China 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. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. 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. 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). First, let's have a look at some key optical parameters are needed to understand focal reducers. The lens is housed in machined aluminum for are machined aluminum black anodized. Also read the reviews here, including those at 4 stars. Some coma is visible in the corners, but the image is quite good for EAA applications. As often noted in reviews and forum threads, Antares products tend to have threads that are a little less precise, and this specimen certainly demonstrated this. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. Also, the focusers of most Newtonians do not have enough in-travel to accommodate a focal reducer.