It can also be used with any other small chip CCD camera having a 1.25" nosepiece, such as the Celestron NexImage, Meade DSI . 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. Several functions may not work. 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. Oceanside Photo & Telescope wants our customers to shop with confidence knowing that you will always get the best deal available. In every configuration, there were essentially parfocal, requiring only a tiny fine focus adjustment when changing correctors. Stock focusers in an SCT move the mirror of the scope to change the position of the focal plane, and they have sufficient travel to accommodate a focal reducer. You cannot, for example, use a 0.63x focal reducer intended for a standard Celestron or Meade SCT and use it on a Celestron Edge HD or a Meade ACF. More details are found in the Appendix of this article. No retailers currently carry this product. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. Reducer Lens .7x - EdgeHD 800 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. Fumbling around in the dark, fine threads might be a problem. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. Sign up to get exclusive deals, observing tips, and new product announcements. Years ago, I bought the Antares version, and moved over to the Celestron. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. Reducer Lens .7x - EdgeHD 800 Learn More. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. However, even though the imprint on the item states "Reducer / Corrector" please note that his is a reducer only. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. 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. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. We process your personal data as stated in our. Sharpness is essentially the same. My application is mostly visual now, but I'm looking to do more astrophotography over time. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. 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. Copyright 2021 Stargazers Lounge One of the most important factors in a telescope is its transmissionthe percentage of light that reaches the focal plane. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? Description. 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. The lens that the ZWO comes with give a perfect wide angle image of what is in front of it. Thanks guys, appreciate the feedback. The more focal reduction, the further inward the focal plane will be. Thanks for the extremely valuable article. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. That was fun. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. ), 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. The working distance or required back focus, explained above, is usually specified and is far more important in practice. Antares or Celestron? Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. 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. Practical Considerations of Focal Reducers, 4.2 Back Focus Requirements of Focal Reducers, GSO makes focal reducers for their line of Ritchey-Chretien, Celestron makes a series of focal reducers for the Edge HD line, 0.75x focal reducers for these telescopes, focal reducer for an 8-inch Celestron EdgeHD, A Primer on T-Rings and T-Adapters for Astronomy and Astrophotography, Choosing the Best Telescope for Beginners 2023, Top Night Sky & Astronomy Events in August 2022, Top Night Sky & Astronomy Events in July 2022, Selecting a Baader Planetarium Star Diagonal, A Guide to Choosing Astronomy Eyepieces for Binoviewers, Choosing a Magnifying Finder Scope for Your Telescope, A focal reducer will provide its design reduction factor only when it is placed at the exact working distance from the focal plane of the eyepiece or camera, Reducing the operating distance, that is, moving a focal reducer closer to the eyepiece or camera increases its reduction factor, or conversely reduces the amount of focal reduction. Unlike . Also, the focusers of most Newtonians do not have enough in-travel to accommodate a focal reducer. A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. Many Ritchey-Chretien telescopes available today are made by GSO. 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. Not noticed any optical problems. 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. For imaging, a T-adapter is threaded to the camera side of the focal reducer, which in turns connects to the camera with the appropriate hardware. 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. This would tell us exactly how well aberrations are corrected. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. 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. In terms of reduction and correction - which are what reducer/correctors are supposed to do - both are superb. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. They are reported as identical. I was referring to the C6 to answer you specifically. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. The focal length and design working distance for this focal reducer were not available from the manufacturer. None of this was offensive, nor did it interfere with views in any significant way. But while the image gets brighter, the size of the image circle gets proportionately smaller. For the best experience on our site, be sure to turn on Javascript in your browser. In this case, d2 = FR/2, which means the back of the focal reducer is located at a distance FR/2 from the camera or eyepiece. 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). I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. 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. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. For example, with a 0.8x focal reducer, a telescope with a focal length of 800mm will operate at 800 x 0.8 = 640mm when the reducer is placed at the working distance specified by the manufacturer. The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. 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. 2023 OPT Telescopes. 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. Never used one, but read the reviews here that suggest a coating problem. However, these will not impact optical performance. In such cases, we will be happy to take the item back as per our standard return terms. The Celestron f/6.3 is ~150 compared to the Antares at ~70. I use it on my C8 SCT with a 1000d, and it seems to do everything written on the tin. The female end attaches to the rear cell of the telescope. The f/6.3 reducer is operating at f/5-f/5.5 with a 2" diagonal, depending on the back focus length of the diagonal. We only send interesting emails and will never sell your data. Again, to my surprise, there was absolutely no difference between the Celestron and Antares on any star. Nada. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. 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. Enter it during checkout! Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. Like many of us with SCTs, I have bought and sold a number of f/6.3 reducer/correctors over the years, and I have always been curious how they really stack up to each other. 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. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? control and Sky Viewer display makes selecting your target easy. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. It must be in stock at the time of Price Match for us to make a guarantee. 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. CEL-94245. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. It is not a corrector or flattener. Reducer Lens .7x - EdgeHD 1400 Learn More. 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. 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. 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. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Reducer Lens .7x - EdgeHD 925 Very helpful, thanks a lot for this article! Go behind the scenes with Celestrons product development team and learn more about our award-winning and patented innovations. My Celestron was made in China and the Antares in Canada. 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. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). To further factor out my natural astigmatism (I normally wear glasses while observing), I did the tests with my regular progressive lenses, single vision glasses I use when observing, and naked eye. Field stop diameters are one of the specified specs of eyepieces. Explicitly designed for Celestron Schmidt-Cassegrain telescopes, this unique lens reduces your telescopes focal length and f/ ratio by 37%, turning your long focal length telescope into a fast, short focal length instrument. But when not in the box or on the telescope, there is no cover for the other end. 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. 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. For this test, I used a single configuration R/C, Click-lock, and 1.25 diagonal with the adapter. Meade once made an f/3.3 focal reducer for SCT scopes. If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. October 11, 2010 in Discussions - Scopes / Whole setups. Thanks guys, I'm trying to get my ZWO ASI120MC-S to work with my 90mm Meade. Focal reducers (and focal reducer/field flatteners combos) are usually used with two types of telescopes, refractors and compound telescopes such as Schmidt-Cassegrain or Ritchey-Chretien. 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. We do not price match competitors if they are out of stock. We reserve the right to verify a competitor's advertised price and the availability of the item. 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. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. There is a way to make subjective data more useful and that way is proper blind, or better still. Because most modern Newtonians already have relatively fast focal ratios, these telescopes do not usually use focal reducers. Just one question. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. You currently have javascript disabled. 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 Obviously bright objects like Jupiter or The Moon show the reflections. I wish there was. These RC reducers cannot be used with other types of telescopes. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA, Availability: Item has been discontinued by Agena and we no longer carry this item. 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. 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. 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. You may need spacers or a T-adapter to ensure the correcting working distance. Brian Ventrudo is a writer, scientist, and astronomy educator. I focus using a moonlight electronic focuser and focusmax. 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.