For the best experience on our site, be sure to turn on Javascript in your browser. With the Celestron Reducer/Corrector Lens, thats precisely what you get. 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). The review is a subjective visual impression, which is interesting but not best evidence. Things change but when I rebought I got an Antares and it seems about the same to me. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). Reducer Lens .7x - EdgeHD 1400 Learn More. Yet, the Antares still easily and fully threaded without any hitches. The naming convention of SCT focal reducers is a little confusing. Celestron or Antares f/6.3 focal reducer for SCT? However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. Maybe I got a lemon. This is the simplest way to attach your ASI121 to your telescope. Brightness, color, and contrast were subtly different, but could be as much the day they were coated as any real difference in the two brands. They usually have a 2" barrel that slides into the telescope focuser. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. A wider field of view and a lower magnification is also useful, with some focal reducers and with some eyepieces, for visual observers with telescopes with long focal ratios. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. 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. If used with other f/ratios, the field flattening characteristic may be unpredictable. In every configuration, there were essentially parfocal, requiring only a tiny fine focus adjustment when changing correctors. Article Agena AstroProducts, 2019. 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 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. In terms of reduction and correction - which are what reducer/correctors are supposed to do - both are superb. In such cases, we will be happy to take the item back as per our standard return terms. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. For Ritchey-Chretien telescopes such as those manufactured by GSO, there are also dedicated focal reducers with a reduction factor of 0.7x to 0.8x. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. 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. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. I even lost track of which reducer I was using. How about for visual observers? 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. Can these economical focal reducers from GSO and other vendors result in good images? Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. Thanks for pointing this out. Reducer - Corrector Learn More. Specially-designed focal reducers are available for use with these telescopes. Thanks guys, I'm trying to get my ZWO ASI120MC-S to work with my 90mm Meade. We reserve the right to verify a competitor's advertised price and the availability of the item. For this test, I used a single configuration R/C, Click-lock, and 1.25 diagonal with the adapter. Powered by Invision Community. 2023 OPT Telescopes. Once focused it's pretty good. You may need spacers or a T-adapter to ensure the correcting working distance. All rights reserved. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. Add a 0.63x reducer, and the brightness of extended objects increases by (1/0.63)2 = 2.5. 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. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. Due to the design, the Reducer/Corrector lens does diminish a small amount of field curvature common to all Schmidt Cassegrain telescopes but does not eliminate it. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer. Place the plastic covers on the lens when not in use to reduce the dust collection. Yellow and orange members of open clusters stood out a bit more as the various stars displayed their individuality. ), but stars seemed a bit tighter and their colors were richer and more dramatic. 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. 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. Despite never removing it no matter what I was looking at. Brian Ventrudo is a writer, scientist, and astronomy educator. 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. The threads were similar on the eyepiece end, but a bit smoother. The lens has a knurled surface, providing a tremendous gripping surface for threading/unthreading. The reducer fits all Meade and Celestron . 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. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. - thanks. You currently have javascript disabled. Possibly the design of the Antares was changed .. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. Reducer Lens .7x - EdgeHD 1100. Sign up to receive sale alerts, news about upcoming celestial events, and telescope tips from our experts! 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. Right off the bat, I was struck by how similar the two R/Cs were. We will match any online price that we confirm as valid. He also holds a Ph.D. in engineering physics from McMaster University. It is not a corrector or flattener. Sharpness is essentially the same. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. If you do so, you will achieve the design reduction factor. Many focal reducers are meant to be used within a few millimeters of the specified working distance to achieve the best possible image results. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. Many Ritchey-Chretien telescopes available today are made by GSO. 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. ), 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. 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. control and Sky Viewer display makes selecting your target easy. It can also be used with any other small chip CCD camera having a 1.25" nosepiece, such as the Celestron NexImage, Meade DSI . Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. 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. Reviews. We have tested our current batch and it works with Meade, Celestron, and Baader SCT accessories. 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. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. This was most noticeable on the eyepiece end of the RC, where the metal rim surrounding the lens was about 1mm thicker than on the Celestron. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. Melotte 15 - First Process in PixInsight (easy! 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). It must be in stock at the time of Price Match for us to make a guarantee. I've only used it a few times but it looks good to me. 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. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. Photographically you also get a wider field and much shorter exposures. 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. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. Most manufacturers provide this specification. 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 very impressive performance given how hard this problem is to mitigate in general. By using this site, you agree to our Terms of Use. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. The Reducer/Corrector can also be used for terrestrial digiscoping. Product Details. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. The most significant mechanical variation, however, is the quality and precision of the threading. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. At least these two units I tested make the answer - whatever. Description. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. It's highly unlikely that they could be so precisely identical unless they were. It has only one cover, which surprised me. 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? 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. 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. 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! 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. Community Forum Software by IP.BoardLicensed to: Cloudy Nights, E of San Francisco Bay and W of the Awahnee, This is not recommended for shared computers, reviews here that suggest a coating problem, Back to Celestron Computerized Telescopes, Looking for advice on first refractor and camera. Reducer Lens .7x - EdgeHD 800 Learn More. I have had the Japan unit on the back of my C5 since 1994 or thereabouts. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. Thks for that and its not for visual it for astrophotography. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. Never noticed any anomalies with this unit. 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. This fully multi-coated lens provides maximum light transmission with near full-field illumination. 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. Reducer Lens .7x - EdgeHD 800 I focus using a moonlight electronic focuser and focusmax. Thanks for the extremely valuable article. Each focal reducer has a fixed specification called the working distance or required back focus. Most focal reducers are designed to operate optimally at the working distance in the optical path to achieve their specified reduction factor, which is usually between 0.5x and 0.8x. No idea what the issue is. They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. Unlike . This may be a problem if the focuser tube or the diagonal (for visual observing) is too narrow to accept light at this larger angle. 2. With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. 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. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. For the best experience on our site, be sure to turn on Javascript in your browser. Your price: $579.00. 800-483-6287 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. Any comments gratefully received. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. It's easy! The most popular accessories for your new telescope! The equations in the Appendix show how this all works. He tested this on an 8 Celestron , I have a Celestron 6SE. There are many different types of focal reducers and they all effect. Reducer Lens .7x - EdgeHD 1400 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. Again, to my surprise, there was absolutely no difference between the Celestron and Antares on any star. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. I have the Antares and have no complaints. 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. I own both and concur heartily. Meade does not make an equivalent line of focal reducers for the ACF scopes, although some models of Meade ACF are already at f/8, faster than the f/10 ratio of Celestron Edge HD scopes. I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. 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. 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. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. looks virtually identical, except for the lettering. 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. 1.2" in that scope is a field stop of 43mm at f/10 and 27mm at f/6.3. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. Please note, orders placed after 10am on 2/28/2023 will be delayed. How does it look thats what matters. Now It only focuses near things, like some kind of macro zoom. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. I wont bother with differences in packaging, caps, etc. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. Go behind the scenes with Celestrons product development team and learn more about our award-winning and patented innovations.

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