Sign up for OPT news, exclusive offers, and updates on the latest gear! Not one detectable iota of discernable difference. I use the same back spacing for both on a small 6" Celestron SCT. Thanks guys, I'm trying to get my ZWO ASI120MC-S to work with my 90mm Meade. We reserve the right to verify a competitor's advertised price and the availability of the item. 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! Explore Scientific Keys to the Universe Sale. Reducer Lens .7x - EdgeHD 925 All Rights Reserved. There are many different types of focal reducers and they all effect. 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. I also used several eyepieces including the ES 24mm/68, 17.5mm and 12.5mm Morpheuses, and a 10.5mm Pentax XL. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. I have this one Opticstar F6.3 Focal Reducer / Corrector. 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. My application is mostly visual now, but I'm looking to do more astrophotography over time. Possibly the design of the Antares was changed .. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; The threads were similar on the eyepiece end, but a bit smoother. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. Great for home, classroom, or home-school use, this kit includes all the essential items youll need to begin exploring the wonders of the microscopic world. 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. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. If you do so, you will achieve the design reduction factor. With the Celestron Reducer/Corrector Lens, thats precisely what you get. The price for an item/offer must be listed and valid at the time of match. 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. F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. InternetSales@optcorp.com. No idea what the issue is. By My experience is that CN sellers are way above those listing elsewhere. 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 . 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. 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). I think that the FRs made in Japan in the day may have been better. The stars at the edge could be worse or better. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. Given the results of Test #1, I wanted to see if there was any truth to this assumption. 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. At a significantly lower price point, the Antares is a steal, and theres no need to upgrade to the Celestron if you already have one. Is that distance D= Fo-d1=Fo-(d2/MR)? Maybe I got a lemon. looks virtually identical, except for the lettering. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. 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. Your mileage may vary. 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. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. Observing the microscopic world has never been easier! 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. It is not a corrector or flattener. During check-out, you will be presented with several shipping choices and costs. control and Sky Viewer display makes selecting your target easy. Copyright 2003-2022 Agena AstroProducts. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. More details are found in the Appendix of this article. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). Copyright 2021 Stargazers Lounge But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. However, this also came at a cost, as the sky background in the Antares was slightly brighter. Get ready for a night of astroimaging with your mount faster than previously thought possible with All-Star Polar Alignment. 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 It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. 3. 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. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Check out our 2022 telescope buying guide here! 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. Try & buy if you like - usual mates rates. If yes, what kind of focal reducers can I use? Michael 1 ronin Members Increase that distance, and greater reduction results and visa versa. I even lost track of which reducer I was using. 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. Thanks. Style: But while the image gets brighter, the size of the image circle gets proportionately smaller. 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. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. Celestron or Antares f/6.3 focal reducer for SCT? Orders placed after 12:00 PM Pacific Time will be shipped the next business day. 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. 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. 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. I am new to these optic topics, and I want to ask you what happens with Masutov like SW or Celestron 4 or 7 inches. With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? 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. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. The naming convention of SCT focal reducers is a little confusing. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. 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. They never really recovered from selling a few 15 years back with element reversed. He tested this on an 8 Celestron , I have a Celestron 6SE. Unscrew that wide angle lens and put it away, then attach the ASI120 to the nose-piece that came with the camera and fit that into the eyepiece holder. I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. You may need spacers or a T-adapter to ensure the correcting working distance. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Many focal reducers for refractors have a working distance (or back focus distance) of 55mm. 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. Once focused it's pretty good. Thanks Peter! He received his first telescope at the age of 5 and completed his first university course in astronomy at the age of 12, eventually receiving a master's degree in the subject. Wonder how they would stack up with a Japanese 6.3. 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. 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. Have always disliked the crude, noisy SCT threads, but I get it. CPWI has an extensive object database, employs PointXP mount modeling, and more. Read our 101 article or get in touch. Hi - most interesting - may I ask .. the brighter guys - "if a camera sensor is too small for a n adaper, will a focal reduer allow me to get greater use from the camera? JavaScript seems to be disabled in your browser. 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). Well done. WiFi technology encircles the globe in a web of connectivity, knowledge, and information. Many Ritchey-Chretien telescopes available today are made by GSO. GSO, for example, has a 0.75x reducer for RC scopes with a back focus of 80mm, which is usually enough room for a wide range of astronomy cameras and accessories and spacers as needed. We will match any online price that we confirm as valid. 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. 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. Can these economical focal reducers from GSO and other vendors result in good images? 2023 Celestron, LLC. He also holds a Ph.D. in engineering physics from McMaster University. Brightness, color, and contrast were subtly different, but could be as much the day they were coated as any real difference in the two brands. If it's positioned further from the eyepiece or camera and closer to the telescope objective, the reduction factor increases. The focal length and design working distance for this focal reducer were not available from the manufacturer. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. JavaScript seems to be disabled in your browser. Powered by Invision Community. The most significant mechanical variation, however, is the quality and precision of the threading. I have the Antares and have no complaints. 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! Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Anyway, when purchased my R/C the "original" Celestron unit was not readily available and was offered instead the one sold under the shop's own label (in my case Tecnosky, but I saw the same product offered under TS label). 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. This should not be the case if they have their purportedly different focal lengths. 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. If you want to save a few buck watch the classifieds on CN. One problem with getting opinions is that most of use do not have both reducers or have never done a side by side comparison. This is the simplest way to attach your ASI121 to your telescope. because they really dont matter. Some third-party vendors also make reducers for SCT scopes. Thks for that and its not for visual it for astrophotography. 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. Hi. 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. October 11, 2010 in Discussions - Scopes / Whole setups. I wont bother with differences in packaging, caps, etc. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. I've looked through one from Meade and first impression was that it was like the Celestron version. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. For the best experience on our site, be sure to turn on Javascript in your browser. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. It works fine but you should stick with 1.25 EPs; or can use 2" EPs without corrector. 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. Wow, that is a very detailed discussion! 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. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. Add a 0.63x reducer, and the brightness of extended objects increases by (1/0.63)2 = 2.5. 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"). Reducer Lens .7x - EdgeHD 1400 Your price: $579.00. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Steve 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. Antares or Celestron? EclipSmart solar products feature Solar Safe filter technology providing the ultimate protection from harmful solar radiation, including both IR and UV light, and filters 99.999% of visible light. Go behind the scenes with Celestrons product development team and learn more about our award-winning and patented innovations. High power views will provide flatter fields all the way to the edge, both visually and photographically. As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. . Orders placed over the weekend will be shipped on the following Monday. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. DUE TO EXTREMELY HIGH DEMAND, WE WILL NOT BE TAKING NEW ORDERS UNTIL MONDAY, DECEMBER 14. Several functions may not work. However, doesn't fit in the telescope and even if it did wouldn't work. Some are available in 1.25" barrel format but with C threads. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. Fortunately, my neighbors are not out in their backyards at 11 pm, or they may have thought I was torturing a small mammal. 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 . That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. It was used strictly for imaging, not visual observing. 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%. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. 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. Reducer Lens .7x - EdgeHD 925 Learn More. You currently have javascript disabled. We do not price match competitors if they are out of stock. 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. But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. Explore Scientific - Keys to the Universe Sale. But I am rusty, can you condense a bit for me please? The nominal design reduction factor of these reducers is typically 0.5x. Reducer Lens .7x - EdgeHD 1100. Yet, the Antares still easily and fully threaded without any hitches. The visual back must be removed first. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. 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. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. We process your personal data as stated in our. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. However, these will not impact optical performance. 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. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. They are also less expensive than many external focusers of similar build quality. Generally, views through the Antares seemed a little more transparent and brighter. By using this site, you agree to our Terms of Use. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. 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. 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. Sign up for a new account in our community. Nebula Filters. Field stop diameters are one of the specified specs of eyepieces. I have an 8SE, and am thinking about getting a focal reducer. 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. 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. 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. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. Opticstar F6.3 Focal Reducer / Corrector. Request stock alerts and we'll let you know when the item is back in stock. ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Reducer Lens .7x - EdgeHD 1100 Learn More. Your eyepieces are the first accessories you should learn to use with your telescope. Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. Such an image circle is still large enough to encompass the relatively large sensor of many deep-sky astronomy cameras. I focus using a moonlight electronic focuser and focusmax. I own both and concur heartily. So it provides a 0.63x design reduction factor when used with an f/10 SCT at the specified working distance. Contiguous US Customers:All items we sell ship for free within the Contiguous US. However, I noticed immediately that the Antares had a bit more of an heft to it, giving it a solid feel the Celestron didnt possess. You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. You attach the focal reducer to the rear port on a SCT and can keep it covered. Most manufacturers provide this specification. Overall, this reducer does a phenomenal job at preventing gradients due to internal reflections from the camera sensor back to the glass in the reducer, as I suffered with the Antares reducer. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. When using the diagonal, keep the field stops of the eyepieces under 20mm. Using one on such a scope would make demands on the eyepiece design and increase the exit pupil to an extent that focal reduction on fast Newts is not practical. Again, to my surprise, there was absolutely no difference between the Celestron and Antares on any star. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. Meade and Celestron both sell such SCT-T adapters with the correct optical length. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. Enter it during checkout! The Antares FR2-0.7X is the same 4-element f/6.3 lens system used for f/10 Schmidt-Cassegrain telescopes but in a 2" barrel threaded for standard filters. Please re-enable javascript to access full functionality. Stars in the corner of the image frame are indistinguishable between the Antares and the Celestron. The Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes is a low-price option for reducing the focal length of your Schmidt-Cassegrain telescope from f/10 to f/6.3. Benefits limited to hardware and conditions? Copyright 2003-2022 Agena AstroProducts. For visual use, this means you get lower power with the same eyepiece and a wider field of view. 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. If used with other f/ratios, the field flattening characteristic may be unpredictable. 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. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. I am a purely visual observer, so will evaluate for visual use only. The Celestron f/6.3 is ~150 compared to the Antares at ~70. Thanks for the extremely valuable article. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. Read our guide! But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. 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. No results, please adjust your filters. Because most modern Newtonians already have relatively fast focal ratios, these telescopes do not usually use focal reducers. The internal surfaces are blackened and glare-threaded to provide the highest contrast. . 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. CEL-94245. Reducer Lens .7x - EdgeHD 800 Learn More.

Wex Fleet Card Product Codes, Spanish Revival Furniture For Sale, 333 Grand Street, Jersey City, Washington County, Md Arrests, How To Read Expiration Date On Ragu Sauce, Articles A