Quite interestingly it bears the very same engravings of the Meade 4000 r/c (including "series 4000") except for "MEADE". There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. 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. Thanks for the extremely valuable article. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. Focal reducers for SCT, RC, and field-flattened Edge HD or ACF telescopes thread onto the back of the telescope tube with 2"-24 or 3"-28 SCT threads. He also holds a Ph.D. in engineering physics from McMaster University. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. Field stop diameters are one of the specified specs of eyepieces. It's usually specified in millimeters. 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. These RC reducers cannot be used with other types of telescopes. But I am rusty, can you condense a bit for me please? The equations in the Appendix show how this all works. 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). The price for an item/offer must be listed and valid at the time of match. We do not price match competitors if they are out of stock. Stars had a tiny bit more sparkle and pop. Michael 1 ronin Members One problem with getting opinions is that most of use do not have both reducers or have never done a side by side comparison. Yet, the Antares still easily and fully threaded without any hitches. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. But nearly every observer who installs one of these devices is pleased with their performance. I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. which looks like the same one. There are also third-party vendors such as Hotech. 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. 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. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions. This is one of our best-selling items, and customers have reported that this product is at least as good as, and probably better than, other leading f/6.3 focal reducers sold on the market for a lot more. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. The most popular accessories for your new telescope! I only have the Celestron f/6.3. Our patented SkyAlign alignment technology makes setting up a computerized telescope simple, fast, and accurate. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. 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. Product Details. I use the same back spacing for both on a small 6" Celestron SCT. 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. Enter it during checkout! Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. By 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). Some coma is visible in the corners, but the image is quite good for EAA applications. A focal reducer does just the opposite of a Barlow lens or focal extender. 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. Turn it on and push Align. In about three minutes, youre ready to observe! 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. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. Celestron Solar Safe filter technology is GUARANTEED SAFE for direct solar observation and has been independently tested by SAI Global Assurance Services. 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. 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. You need to be a member in order to leave a comment. The stock Celestron visualback is just under 2 long. 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. Planetarium software package which provides easy-to-understand explanations and impressive visuals of all kinds. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. What an enjoyable read and detailed comparison. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. 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. If used before or beyond the working distance, unwanted image distortion may result. 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. 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. Some are available in 1.25" barrel format but with C threads. The Antares focal reducer comes in small box. 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. Figure 2 shows the effective of a focal reducer on the light from a telescope objective. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. 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. 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. 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. 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. Antares Click Lock Visual Back - posted in Cats & Casses: Here is the situation:I bought a Celestron CPC 1100 for visual use.Want to put on the scope simulteanously a6.3 focal reducer, filter wheel, and aneyepiece turret. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. It seems right to put some distance between the camera and the focal reducer, right? For the best experience on our site, be sure to turn on Javascript in your browser. However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? We only send interesting emails and will never sell your data. Free shipping $189.95 Start Chat Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. 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. 800-483-6287 Perfect for the serious student, professional scientist and discriminating hobbyist. Images in the Celestron tended to appear ever-so-slightly dimmer (maybe? Not noticed any optical problems. Oceanside Photo & Telescope wants our customers to shop with confidence knowing that you will always get the best deal available. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. It is recommended for . Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; I've never found my 0.63 reducer causing CA when used with my SCT. Thks for that and its not for visual it for astrophotography. 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 most significant mechanical variation, however, is the quality and precision of the threading. Generally, views through the Antares seemed a little more transparent and brighter. 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. Thanks guys, I'm trying to get my ZWO ASI120MC-S to work with my 90mm Meade. 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. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Thanks for pointing this out. So, if you have a filter that is 3mm thick, you need to add 1mm of spacing to your imaging train to retain the correct back focus. The stars at the edge could be worse or better. Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. CPWI has an extensive object database, employs PointXP mount modeling, and more. 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. 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. An f/6.3 reducer is designed to reduce the focal ratio of an f/10 SCT to f/6.3. If used with other f/ratios, the field flattening characteristic may be unpredictable. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. 1.2" in that scope is a field stop of 43mm at f/10 and 27mm at f/6.3. I have Hirsch focal reducer, which is yet another clone of the Celestron reducer. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads My experience is that CN sellers are way above those listing elsewhere. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. There is a way to make subjective data more useful and that way is proper blind, or better still. 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. By using this site, you agree to our Terms of Use. 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. ), 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. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. 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. Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. I don't know. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. These reducers have a back focus (or design working distance) of 80mm. 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). No idea what the issue is. Reducer Lens .7x - EdgeHD 800 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. 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. 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. 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). This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. No retailers currently carry this product. 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. - thanks. They are reported as identical. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. Your price: $579.00. 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. For the best experience on our site, be sure to turn on Javascript in your browser. As I understand it, compared to the old Meade SCT's, the ACF is already "coma corrected", so the standard Meade, Celestron etc F6.3 focal reducers are not suitable and will only worsen the images. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. Again, these focal reducers are often provided by the telescope manufacturer. Please re-enable javascript to access full functionality. Bear in mind you can't squeeze blood out of a turnip, i.e. For example, many focal reducers designed for f/7 or f/8 ED refractors such as those from Tele Vue, William Optics, Sky-Watcher, and Meade are designed to have a working distance (or back focus) of 55mm. Please let us know what topics you are interested in. But when not in the box or on the telescope, there is no cover for the other end. 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. Depending on the design of the telescope, they may require separate focal reducers if they require focal reducers at all. 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. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. 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. Also read the reviews here, including those at 4 stars. A few large telescopes and mounts are excluded from this free shipping offer. The visual back must be removed first. If yes, what kind of focal reducers can I use? I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. Fortunately, my neighbors are not out in their backyards at 11 pm, or they may have thought I was torturing a small mammal. 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. Reducer Lens .7x - EdgeHD 925 Learn More. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. 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. 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.
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