Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. Because most modern Newtonians already have relatively fast focal ratios, these telescopes do not usually use focal reducers. I'm going with the Celestron. No idea what the issue is. A couple of tiny dust particles between lens elements, uneven lens edge blackening, very minor coating blemishes, or even a very small fine lens scratch or two are very common in this Antares product and must be accepted as normal for this item. Free shipping $189.95 DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. That said any comparison reviews are helpful. 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. Copyright 2003-2022 Agena AstroProducts. 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. I've only used it a few times but it looks good to me. I even lost track of which reducer I was using. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. Thanks for pointing this out. Orders placed over the weekend will be shipped on the following Monday. Reviews. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. 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. 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 I wont bother with differences in packaging, caps, etc. 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. Completely stuck, completely frustrated. 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. 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. 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. Just one question. Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. You also wont be unhappy spending the few extra bucks on the Celestron for the pretty orange lettering, particularly if you can pick one up used, as I did. 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). Orders placed after 12:00 PM Pacific Time will be shipped the next business day. One problem with getting opinions is that most of use do not have both reducers or have never done a side by side comparison. Our patented SkyAlign alignment technology makes setting up a computerized telescope simple, fast, and accurate. Now It only focuses near things, like some kind of macro zoom. Reducer Lens .7x - EdgeHD 925 Clean, fun jokes the tradition continues - Page 106 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. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. I have this one Opticstar F6.3 Focal Reducer / Corrector. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. Just point the telescope at any three bright objectsstars, bright planets, or even the Moonand your telescope can orient itself with the night sky. F 6.3 focal reducer/corrector. - Discussions - Stargazers Lounge That was fun. However, in principle, the reduction factor of a focal reducer can be varied by changing the distance from the back of the focal reducer to the camera or eyepiece. 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. Style: 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. 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. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). 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. 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. 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. The more focal reduction, the further inward the focal plane will be. 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. Take control of your telescope! Please re-enable javascript to access full functionality. 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. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. A focal reducer does just the opposite of a Barlow lens or focal extender. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. InternetSales@optcorp.com. As mentioned in Section 2.3, the reduction factor for these focal reducers can be varied by adding spacers to move the reducer further from the camera sensor or eyepiece. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration. If I had to guess, the difference is maybe 10-15 grams. I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. 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. I have Hirsch focal reducer, which is yet another clone of the Celestron reducer. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. All additional accessories mount onto the exterior/male threads. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. Increase that distance, and greater reduction results and visa versa. Does anyone have any experience with the Celestron and Antares focal reducers? The Antares is supposed to be pretty comparable. Can you help me? For Stephen Wilkerson: The ZWO ASI120MC-S does come with a wide angle lens, HOWEVER, it is NOT intended to used when you are using the ASI120 camera attached to your telescope. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. I have the Japanese version and although I haven't used it in quite awhile, the views through it were superb with no internal reflections at all. Some coma is visible in the corners, but the image is quite good for EAA applications. Meade once made an f/3.3 focal reducer for SCT scopes. But when not in the box or on the telescope, there is no cover for the other end. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. I must admit, as well, that I no longer place a lot of stock in the notion that Chinese optics are inferior to Japanese or Taiwanese any longer, as manufacturing technology has really leveled the playing field today, with most Chinese optics being excellent. 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. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Each focal reducer has a fixed specification called the working distance or required back focus. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Sign up to receive sale alerts, news about upcoming celestial events, and telescope tips from our experts! They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. Celestron or Antares f/6.3 focal reducer for SCT? Rather than a direct side-by-side, I swapped the reducers so that I was using them on the exact same, well-collimated instrument. Here, there was a subtle difference . There are also third-party vendors such as Hotech. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. Have a promo code? 0.63x Starizona Focal Reducer for SCTs- Awesome Astrophotography Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. 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. 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! 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. 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. Turn it on and push Align. In about three minutes, youre ready to observe! 2023 OPT Telescopes. Some are available in 1.25" barrel format but with C threads. 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. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. Please Log in to save it permanently. The working distance or required back focus, explained above, is usually specified and is far more important in practice. If used with other f/ratios, the field flattening characteristic may be unpredictable. 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. First, let's have a look at some key optical parameters are needed to understand focal reducers. control and Sky Viewer display makes selecting your target easy. And, the reality is that every F/6.3 RC out there Celestron, Hirsch, Astromania, etc., etc. The designed reduction factor (0.5x in the case of the GSO reducer example above) should be considered a rule of thumb or approximate value in most cases, rather than a very precise number. If yes, what kind of focal reducers can I use? A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. It's important to match the back focus to within a millimeter or two to get an optimal image, especially with cameras with larger sensors. But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. The Antares focal reducer comes in small box. Focal Reducers - Complete Overview and Function - YouTube 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. How does it look thats what matters. This is very impressive performance given how hard this problem is to mitigate in general. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. If you do so, you will achieve the design reduction factor. Reducer Lens .7x - EdgeHD 1100 Learn More. 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. No small animals were harmed in making these observations. 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. Place the plastic covers on the lens when not in use to reduce the dust collection. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Copyright 2021 Stargazers Lounge Steve We have placed cookies on your device to help make this website better. It has only one cover, which surprised me. For the best experience on our site, be sure to turn on Javascript in your browser. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. If it's positioned further from the eyepiece or camera and closer to the telescope objective, the reduction factor increases. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. 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. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. Wonder how they would stack up with a Japanese 6.3. The stars at the edge could be worse or better. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. If you want to save a few buck watch the classifieds on CN. 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. 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. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. 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. I've looked through one from Meade and first impression was that it was like the Celestron version. I use the same back spacing for both on a small 6" Celestron SCT. The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. Copyright 2003-2022 Agena AstroProducts. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. 2023 Celestron, LLC. 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. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; For the best experience on our site, be sure to turn on Javascript in your browser. I was referring to the C6 to answer you specifically. Upgrading the Focuser of Your Schmidt-Cassegrain Telescope - Agena Astro Astro-Tech Schmidt-Cassegrain f/6.3 Focal Reducer Field Flattener A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. It must be in stock at the time of Price Match for us to make a guarantee. It features a standard male SCT thread (2" OD, 24 TPI) on one side and a standard SCT female thread on the other. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. At least these two units I tested make the answer - whatever. 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. ), but stars seemed a bit tighter and their colors were richer and more dramatic. An image of about 24mm across, approximately, allows an observer to use a 1.25" eyepiece with a maximal field stop. Opticstar F6.3 Focal Reducer / Corrector. Using an eyepiece with a 27mm field stop with the reducer will illuminate the edge the same as using an eyepieces with a 42.9mm field stop without it. 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"). 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. The amount of reduction is simply the percentage by which a reducer shortens the effective focal length of a telescope and is calculated as (1 Reduction Factor) x 100%. The visual back must be removed first. Reproduction without permission prohibited. 800-483-6287 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. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. The review is a subjective visual impression, which is interesting but not best evidence. But nearly every observer who installs one of these devices is pleased with their performance. Reducer Lens .7x - EdgeHD 1100 - Celestron In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. All Rights Reserved. We process your personal data as stated in our. looks virtually identical, except for the lettering. The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). Keep in mind that these differences were very subtle, and could be due to normal variations in coatings among different runs, and not necessarily unique to the brands. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? SKU: CEL-94245. 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. Theres a long-running debate in these forums and even statements from some reputable dealers that the Antares is just a reducer (even though it is labeled Reducer/Corrector), whereas the Celestron is a true R/C, which flattens the SCTs naturally curved field and provides some edge correction. Figure 2 shows the effective of a focal reducer on the light from a telescope objective. and you will be fine. I am a purely visual observer, so will evaluate for visual use only. Powered by Invision Community. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. 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. This is the simplest way to attach your ASI121 to your telescope. Maybe I got a lemon. 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. . I found both to be very good. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. 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. Depending on the design of the telescope, they may require separate focal reducers if they require focal reducers at all. Field stop diameters are one of the specified specs of eyepieces. Housings, threads, reduction, correction, blah, blah, blah. That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. 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. Not one detectable iota of discernable difference. But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. Meade once made an f/3.3 focal reducer for SCT scopes. That means the base of the mounting threads of the focal reducer needs to be 55mm from the camera sensor to achieve the design reduction factor, which is usually 0.8x or 0.85x. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Thks for that and its not for visual it for astrophotography. Melotte 15 - First Process in PixInsight (easy! However, some focal reducers can be used on other models of telescopes, but this is not always possible. 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). Because I have not heard any complaints about the made in China R/C. I think that the FRs made in Japan in the day may have been better. He also holds a Ph.D. in engineering physics from McMaster University. 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. It seems right to put some distance between the camera and the focal reducer, right? Add a 0.63x reducer, and the brightness of extended objects increases by (1/0.63)2 = 2.5. You may need spacers or a T-adapter to ensure the correcting working distance. Celestron or Antares? When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x.