Celestron & Antares f/6.3 Reducer/Corrector Shoot-out The stock Celestron visualback is just under 2 long. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. 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. SKU: CEL-94245. The threads were similar on the eyepiece end, but a bit smoother.
Reducer - Corrector | Celestron However, with appropriate spacers and a camera with a known back-focus, it is easy to determine the exact amount of focal reduction for a given setup (some imaging software packages will also let you derive this from images). More details are found in the Appendix of this article.
Focal Reducer, 2", 0.7X - Antares The working distance (backfocus) of the Celestron f/6.3 reducer is specified to be 105mm from the base of the male SCT thread on the camera side. First, I wanted to compare the actual reduction provided by these competitors, as many threads here cite different ideal spacing from the reducer to eyepiece focal plane to achieve the correct f/6.3 result. It was used strictly for imaging, not visual observing. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. looks virtually identical, except for the lettering. We have placed cookies on your device to help make this website better. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. We will be glad to help.
Back-Focus 101: DSLR Cameras & the Celestron f/6.3 Reducer - YouTube I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. In this configuration, the 29.5mm camera nosepiece and a 6mm extension ring positions the reducer at a working distance of 53.5mm from the camera sensor, which is located 12.5mm inside the front edge of the camera. 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. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. Explore Scientific Keys to the Universe Sale. Hi. Reviews. If yes, what kind of focal reducers can I use? How about for visual observers? I have both the Antares and the Celestron reducers. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. 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. Please note, orders placed after 10am on 2/28/2023 will be delayed. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing.
Reducer Lens .7x - EdgeHD 1100 - Celestron I own both and concur heartily. The previous post shows the reducer on what appear to be two different refractors. 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. 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. Because I have not heard any complaints about the made in China R/C. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. Planetarium software package which provides easy-to-understand explanations and impressive visuals of all kinds. 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. The lens has a knurled surface, providing a tremendous gripping surface for threading/unthreading. Still not sure what is the right gear for you? However I've also read that the back focal distance on the Celestron is 105mm while the Antares is 81mm so they couldn't be identical. 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. 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. 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. 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. F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. 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. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. Field stop diameters are one of the specified specs of eyepieces. Blue Fireball M42 T/T2 Thread Camera Adapter for Prime Focus Photography - 2" # P-06, Celestron T-Ring for Canon EOS Camera # 93419, GSO 2" Crayford Focuser for SCTs - Dual Speed, Length of male SCT thread = 5mm (0.2") but this is preceded by an unthreaded part on the eyepiece side making the total length = 8.8mm (0.35"), Length of female SCT thread = 7.5mm (0.3"). 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. 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. However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. Now It only focuses near things, like some kind of macro zoom. That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. Equation (4) shows the relationship between the distance d2 and the reduction factor MR. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers.
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. 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. It's usually specified in millimeters. Wow, that is a very detailed discussion! More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. 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. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. The design reduction factor of a focal reducer is the relative amount by which the effective focal length of the telescope is reduced when the focal reducer is used at its specified working distance or back focus. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. Sky recognition technology that has revolutionized the manual telescope by eliminating the confusion common among beginners and enhancing the user experience for even seasoned telescope users. But while the image gets brighter, the size of the image circle gets proportionately smaller. 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. The visual back must be removed first. 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.
Astro-Tech Schmidt-Cassegrain f/6.3 Focal Reducer Field Flattener Since the focal plane of an eyepiece is rarely precisely known(except for some brands such as Baader Planetarium and Tele Vue), and because the nosepiece of an eyepiece is of a fixed length, the actual reduction factor will be close to, but not exactly at, its designed reduction factor.
0.5X focal reducer for Celestron, Meade, and Orion CCD imaging cameras It can also be used with any other small chip CCD camera having a 1.25" nosepiece, such as the Celestron NexImage, Meade DSI . Advanced designs for Schmidt-Cassegrain scopes such as the Meade ACF or Celestron Edge HD have optical elements in the tube to correct for coma and field flatness. 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. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. I read another thread in a different forum about F6.3 reducer correctors and one amateur posted an image about glue coming out of an astromania f6.3 reducer which he planned to return. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. 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.
Antares F/6.3 SCT Focal Reducer | OPT Telescopes The equations in the Appendix show how this all works. ED stands for "extra-low dispersion," which refers to the composition and optical properties of the glass used for the lenses. 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. Michael 1 ronin Members Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. 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. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. Some are available in 1.25" barrel format but with C threads. Meade and Celestron both sell such SCT-T adapters with the correct optical length. CEL-94245. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. It's highly unlikely that they could be so precisely identical unless they were. The Antares focal reducer comes in small box. None of this was offensive, nor did it interfere with views in any significant way. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. 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. I even lost track of which reducer I was using. No results, please adjust your filters. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. If the reducer is placed closer to the eyepiece or camera than the distance D, the reduction factor decreases. 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!
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