The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. Because I have not heard any complaints about the made in China R/C. The Celestron f/6.3 is ~150 compared to the Antares at ~70. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. During a twenty-year scientific career, he developed laser systems to detect molecules found in interstellar space and planetary atmospheres, and leveraged his expertise to create laser technology for optical communications networks. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. 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. Who cares? Manish Panjwani has been an active amateur astronomer since before Halley's Comet last flew by our neighborhood. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. As mentioned in Section 2 of this guide, the reduction factor of a focal reducer depends on its position in the optical path relative to the eyepiece or camera. Hence, there is a chance that you may not be able to thread your SCT diagonal or other SCT accessory on to this reducer for these or for any other brand. 1.2" in that scope is a field stop of 43mm at f/10 and 27mm at f/6.3. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. Sign up for OPT news, exclusive offers, and updates on the latest gear! The camera side of the focal reducer is threaded for a T-adapter with wide M48 threads, or in some cases, with smaller M42 threads. 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. 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. Reducer Lens .7x - EdgeHD 1100 - Celestron I am a purely visual observer, so will evaluate for visual use only. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. Reducer - Corrector If the focal reducer is to be used for visual observation, the visual back is threaded onto the eyepiece side of the reducer, and then a star diagonal and eyepiece are installed as usual. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. Sign up for a new account in our community. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. I have an 8SE, and am thinking about getting a focal reducer. . The Celestron f/6.3 is ~150 compared to the Antares at ~70. You need to be a member in order to leave a comment. Reducer Lens .7x - EdgeHD 925 Learn More. 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. The Antares focal reducer comes in small box. 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. Read our guide! No results, please adjust your filters. 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. What I do know is that the Antares and the Celestron samples that I have perform exactly the same from the center right out to the edges. An image of about 24mm across, approximately, allows an observer to use a 1.25" eyepiece with a maximal field stop. One of the most important factors in a telescope is its transmissionthe percentage of light that reaches the focal plane. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions. Now, Celestron is using that same technology to allow star gazers to connect to the night sky and enhance their experience of the cosmos in fun and unique ways. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. and you will be fine. However, this also came at a cost, as the sky background in the Antares was slightly brighter. However, some focal reducers can be used on other models of telescopes, but this is not always possible. because they really dont matter. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; Hmmm . It must be in stock at the time of Price Match for us to make a guarantee. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). 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. Based on Test 1 and Test 2, I think there is perhaps more validity to opposing statements here in these forums that the Antares and current China-made Celestron do, indeed, have exactly the same optics just with different housings and branding. This means that there must be sufficient travel on the telescope focuser to make up for this. I think there may be some confusion here, because Antares makes a variety of reducers for eyepieces and scopes in addition to this SCT R/C but this definitely is a reducer/corrector. I only have the Celestron f/6.3. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. 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 focus using a moonlight electronic focuser and focusmax. They are reported as identical. 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. No small animals were harmed in making these observations. Also read the reviews here, including those at 4 stars. ), but stars seemed a bit tighter and their colors were richer and more dramatic. Completely stuck, completely frustrated. 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. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. Focal Reducers - Complete Overview and Function - YouTube This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. No retailers currently carry this product. The reduction factor MR can also be written in terms of d2 as: When the focal reducer is placed at the working distance, D, that is when d2=D, then the reduction factor MR is equal to the design reduction factor MRD: Equations (6) and (7) imply these important considerations: Most manufacturers do not publish the focal length of their focal reducers, so it is not usually possible to calculate the working distance and design reduction factor. Clearly cost is a big factor for satisfied users. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. The threads were similar on the eyepiece end, but a bit smoother. If you want to save a few buck watch the classifieds on CN. Images made with my ZWO 533 camera testing both show them to be essentially the same. Right off the bat, I was struck by how similar the two R/Cs were. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. Steve If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. It's usually specified in millimeters. Style: The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. Each focal reducer has a fixed specification called the working distance or required back focus. The Buyer's Guide To Eyepieces at the top of the Eyepieces forum has a column for this spec. They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. Reviews. 2. We only send interesting emails and will never sell your data. The working distance or required back focus, explained above, is usually specified and is far more important in practice. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. Meade once made an f/3.3 focal reducer for SCT scopes. 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 used strictly for imaging, not visual observing. Enter it during checkout! Sign up to receive sale alerts, news about upcoming celestial events, and telescope tips from our experts! The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. Even though the manufacturer did not specify the working distance or focal length of this reducer, it is easy to see from this plot that this item provides its stated reduction of 0.5x when it is placed at a working distance of 51.5mm between the base of the threads on the mount and the focal plane of the eyepiece or camera. Back-Focus 101: DSLR Cameras & the Celestron f/6.3 Reducer - YouTube For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. Request stock alerts and we'll let you know when the item is back in stock. The Reducer/Corrector can also be used for terrestrial digiscoping. More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. control and Sky Viewer display makes selecting your target easy. Reducer Lens .7x - EdgeHD 925 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. 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. No negative issues to report. 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. Astro-Tech Schmidt-Cassegrain f/6.3 Focal Reducer Field Flattener Not a bit. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. I use it on my C8 SCT with a 1000d, and it seems to do everything written on the tin. It features a standard male SCT thread (2" OD, 24 TPI) on one side and a standard SCT female thread on the other. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. Please let us know what topics you are interested in. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. Despite never removing it no matter what I was looking at. There are also third-party vendors such as Hotech. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. The Reduction Factor and the Amount of Reduction are inversely related. Antares or Celestron? Celestrons aplanatic EdgeHD optics revolutionized astroimaging. . Your eyepieces are the first accessories you should learn to use with your telescope. Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. Focal reducers for refractors are easy to use. If you do so, you will achieve the design reduction factor. They usually have a 2" barrel that slides into the telescope focuser. I would not use the reducer with a 2" diagonal or eyepiece in the C6. Antares f/6.3 Focal Reducer for SCTs - Awesome Astro Several functions may not work. - thanks. If it's positioned further from the eyepiece or camera and closer to the telescope objective, the reduction factor increases. 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. I have Hirsch focal reducer, which is yet another clone of the Celestron reducer. Focal Reducers | Celestron Please Log in to save it permanently. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. The EdgeHD .7x Focal Reducer Lens makes your EdgeHD 1100 one full F-Stop faster than f/10, reducing your exposure time by half to capture the same brightness of object . Regardless, the difference was miniscule and is more than adequate on both and exceeds a 8 or 6 SCTs baffle tube diameter. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. Thanks. 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. Stars had a tiny bit more sparkle and pop. 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. Focal reducers for refractors with focal ratio of f/7 to f/9, roughly, have a design reduction factor of about 0.75x to 0.8x and produce a flat field by correcting for the curvature of the objective lens. Please re-enable javascript to access full functionality. He also holds a Ph.D. in engineering physics from McMaster University. If a stronger level of focal reduction is used, say 0.5x, then the image circle may be too small to fill the sensor of larger cameras. Maybe I got a lemon. How about for visual observers? 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. Turn it on and push Align. In about three minutes, youre ready to observe! That said any comparison reviews are helpful. M44 was a perfect target for this, as its large size maxes out the FOV on a C8 with a corrector, and its bright stars make great targets for measuring the very edge of the visible field. A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. 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. Download the Celestron PWI Telescope Control Software. 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. Melotte 15 - First Process in PixInsight (easy! Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. The stars at the edge could be worse or better. 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! The more focal reduction, the further inward the focal plane will be. However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. 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. Check out our 2022 telescope buying guide here! 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. It's highly unlikely that they could be so precisely identical unless they were. While most Barlow lenses and focal extenders work with most kinds of telescopes available to amateur astronomers, focal reducers are designed to work in a narrow range of focal ratios of a telescope objective. The working distance of the GSO 0.5x focal reducer with 1.25" barrel and the GSO 0.5x focal reducer with 2" barrel is about 51mm to 53mm, approximately, from the middle of the metal cell that holds the lens. Benefits limited to hardware and conditions? Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes.
Where Is The Itv Meridian News Backdrop,
Highland Park Recreation Center,
Articles A
