Completely stuck, completely frustrated. As one increases, the other decreases. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. Celestron & Antares f/6.3 Reducer/Corrector Shoot-out Reducer Lens .7x - EdgeHD 1100. Will not focus with the stuff I have. 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. Clearly cost is a big factor for satisfied users. 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. An f/6.3 reducer is designed to reduce the focal ratio of an f/10 SCT to f/6.3. WiFi technology encircles the globe in a web of connectivity, knowledge, and information. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Maybe I got a lemon. For the best experience on our site, be sure to turn on Javascript in your browser. Please Log in to save it permanently. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. 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. Yet, the Antares still easily and fully threaded without any hitches. Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. So it provides a 0.63x design reduction factor when used with an f/10 SCT at the specified working distance. Focal Reducer, 2", 0.7X. Contiguous US Customers:All items we sell ship for free within the Contiguous US. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.International Customers:Free shipping does not apply to international orders. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. Sign up to get exclusive deals, observing tips, and new product announcements. 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 reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. 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. This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. They only publish the value of D, the working distance (sometimes called the back focus distance) and the design reduction factor MRD. Celestron or Antares f/6.3 focal reducer for SCT? 3. InternetSales@optcorp.com. JavaScript seems to be disabled in your browser. Celestron Solar Safe filter technology is GUARANTEED SAFE for direct solar observation and has been independently tested by SAI Global Assurance Services. Reducer Lens .7x - EdgeHD 1100 - Celestron However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. Meade and Celestron both sell such SCT-T adapters with the correct optical length. Its a good thing I have the super lube handy or my neighbors wont be happy with me.come to think of it, Im sure the small mammals here wouldnt be thrilled either! 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. control and Sky Viewer display makes selecting your target easy. Well done. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. However, some focal reducers can be used on other models of telescopes, but this is not always possible. This Antares 1.25" 0.5x focal reducer lens (tele-compressor) is used under the Orion brand name to thread into the nosepiece of Orion StarShoot Solar System cameras and StarShoot Deep Space Color Imaging Camera. 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. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. I was going to measure the difference in grams, but my lovely wife caught me trying to use her precious, high-tech kitchen scale for the cause, and put the kibosh on it. Celestron or Antares f/6.3 focal reducer for SCT? Reducer - Corrector 2.2 Using a Focal Reducer at the Working Distance, 2.3 Adjusting the Reduction Factor of a Focal Reducer, 3.3 Focal Reducers for Compound Telescopes, 3.5 Focal Reducers for Ritchey-Chretien and Field Flattened Scopes, 3.6 Focal Reducers in 1.25" and 2" Barrel Formats, 4. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. For the best experience on our site, be sure to turn on Javascript in your browser. Fumbling around in the dark, fine threads might be a problem. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. For visual use, this means you get lower power with the same eyepiece and a wider field of view. Figure 1 shows the relationship between the focal reduction factor MR and the position of the reducer in the optical path. Housings, threads, reduction, correction, blah, blah, blah. The reducer fits all Meade and Celestron . They usually have a 2" barrel that slides into the telescope focuser. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. 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. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. Wow, that is a very detailed discussion! A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Watch this before you buy Celestron 8SE SCT, or a Focal Reducer or a 3. The Antares is supposed to be pretty comparable. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. Today, our world-class team of optical and electronic engineers continues to push the boundaries of technology. I've never found my 0.63 reducer causing CA when used with my SCT. 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. Please let us know what topics you are interested in. Right off the bat, I was struck by how similar the two R/Cs were. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. 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. I have an 8SE, and am thinking about getting a focal reducer. They are reported as identical. 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. We will be glad to help. Again, these focal reducers are often provided by the telescope manufacturer. 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. 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. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. SKU: CEL-94245. Now It only focuses near things, like some kind of macro zoom. 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. I use the same back spacing for both on a small 6" Celestron SCT. 1.2" in that scope is a field stop of 43mm at f/10 and 27mm at f/6.3. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. The Celestron f/6.3 is ~150 compared to the Antares at ~70. Reducer Lens .7x - EdgeHD 1400 Learn More. Also, the focusers of most Newtonians do not have enough in-travel to accommodate a focal reducer. Hmmm . Your eyepieces are the first accessories you should learn to use with your telescope. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; Theoretically each of these combinations all varied-length light paths should have resulted in slightly different reductions between the Celestron and Antares, since they supposedly have different focal lengths. Given the results of Test #1, I wanted to see if there was any truth to this assumption. There are also third-party vendors such as Hotech. 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. This standard distance is a consequence of the design of DSLR cameras for which the distance of the sensor to the outer edge of the flanges is about 45 mm, while the T-ring that attaches to the flange for astrophotography is about 10mm thick. The key points are as follows: So just remember that a smaller distance (from the camera or eyepiece) means a lower amount of reduction (and vice versa). 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. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. Wonder how they would stack up with a Japanese 6.3. Generally, views through the Antares seemed a little more transparent and brighter. 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. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. None of this was offensive, nor did it interfere with views in any significant way. The equations in the Appendix show how this all works. It has only one cover, which surprised me. Reducer Lens .7x - EdgeHD 925 Learn More. For the best experience on our site, be sure to turn on Javascript in your browser. 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. 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. We have placed cookies on your device to help make this website better. 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. Thanks for the extremely valuable article. It's easy! Thanks Peter! Never used one, but read the reviews here that suggest a coating problem. 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. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. The Reducer/Corrector is easy to install by threading the unit onto the rear cell of your Schmidt-Cassegrain telescope (or the reducer plate of the C11 and C14). if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. The nominal design reduction factor of these reducers is typically 0.5x. The author finds differences in throughput and color balance, but then says he thinks the lenses are identical and he reaches his conclusions based on very long observing session. Once focused it's pretty good. You need to be a member in order to leave a comment. I doubt there is any difference between the Antares and the Celestron except price. Copyright 2003-2022 Agena AstroProducts. The lens is housed in machined aluminum for are machined aluminum black anodized. Is that distance D= Fo-d1=Fo-(d2/MR)? An image of about 24mm across, approximately, allows an observer to use a 1.25" eyepiece with a maximal field stop. 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. The female end attaches to the rear cell of the telescope. Most reducers have a design reduction factor, MRD, that assumes the reducer is placed at a specific working distance, D, from the back surface of the focal reducer itself. I have this one Opticstar F6.3 Focal Reducer / Corrector. looks virtually identical, except for the lettering. I think I remember hearing the reduction factor is slightly different, cant remember more or less 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. Clean, fun jokes the tradition continues - Page 106 Unlike . This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. The most popular accessories for your new telescope! 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. Antares f/6.3 Focal Reducer for SCTs - Awesome Astro Stars in the corner of the image frame are indistinguishable between the Antares and the Celestron. With the barrel 1.25 reducer won't focus, all I get is fuzzy snowballs. They are commonly available in 1.25" and 2" threaded cells that conveniently thread into the nosepiece of a compatible camera or the barrel of an eyepiece. 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. It was used strictly for imaging, not visual observing. Enter it during checkout! You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. My experience is that CN sellers are way above those listing elsewhere. 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. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. Steve because they really dont matter. . Read our 101 article or get in touch. Thanks for any advice or experience you could share. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. 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. CEL-94245. This fully multi-coated lens provides maximum light transmission with near full-field illumination. A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. I've only used it a few times but it looks good to me. To test this, I used three set-ups: 1. They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. Each focal reducer has a fixed specification called the working distance or required back focus. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. It might work but it does not tell us anything about how well or to what extent the product works to correct the field of an SCT. It works fine but you should stick with 1.25 EPs; or can use 2" EPs without corrector. Because of their distinct optical design, slower Schmidt-Cassegrain telescopes (SCT) with focal ratios of f/10 require a different design of focal reducer compared to refractors. Celestron Nexstar+ 127 SLT, several budget plossl eyepieces, Celestron 8-24mm zoom EP and a 12.5mm illuminated double reticle EP, Svbony SV205 camera w/.5 focal reducer, Celestron SkyMaster 20x80 binos on a 40 yr old QuickSet PanHead tripod, Stellarium, Sharpcap and ManyCam on my laptop, SkyView and Nightshift on my phone and a dandy little $9 . 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. But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. Reproduction without permission prohibited. No idea what the issue is. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. Still not sure what is the right gear for you? The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. 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. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer. 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. From the SkyProdigy, a telescope so smart it can align itself, to our high-performance EdgeHD optical system, weve revolutionized the hobby of astronomy for beginners and advanced amateurs alike. I was originally hoping to do this with a made in Japan Celestron, but ended up with a newer China version but thats probably better in the end since it is the version now available, with the Japan ones rarer and only available used.
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