Reducer Lens .7x - EdgeHD 1100. I use it on my C8 SCT with a 1000d, and it seems to do everything written on the tin. 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. None of this was offensive, nor did it interfere with views in any significant way. Reducer Lens .7x - EdgeHD 800 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. Sign up for OPT news, exclusive offers, and updates on the latest gear! You may need spacers or a T-adapter to ensure the correcting working distance. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. InternetSales@optcorp.com, 800-483-6287 What I do know is that the Antares and the Celestron samples that I have perform exactly the same from the center right out to the edges. It's usually specified in millimeters. I'd favor the Japanese Celestron version over the others that are commercially available. 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. Unlike . 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. 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. 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. The internal surfaces are blackened and glare-threaded to provide the highest contrast. 800-483-6287 Some third-party vendors also make reducers for SCT scopes. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. . And when d1 = FR, that is, when the focal reducer is placed at a distance from the focal plane of the objective that's equal to the reducer's focal length, the focal length of the combined optical system is Fo, so it acts as a 0.5x reducer. By using this site, you agree to our Terms of Use. That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. Reducer Lens .7x - EdgeHD 925 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. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. Very helpful, thanks a lot for this article! 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. The visual back must be removed first. The Reducer/Corrector can also be used for terrestrial digiscoping. ED stands for "extra-low dispersion," which refers to the composition and optical properties of the glass used for the lenses. For the best experience on our site, be sure to turn on Javascript in your browser. 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. 2. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. 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. I use the Celestron version and it seems OK for both visual and imaging. The two samples I have PERFORM IDENTICALLY. This should not be the case if they have their purportedly different focal lengths. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. The click-lock with a 2 dielectric diagonal with a somewhat shorter light path, using both a 2 ES 28mm/68 and the same low-profile adapter with a 1.25 ES 24mm/68. At least these two units I tested make the answer - whatever. 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. Things change but when I rebought I got an Antares and it seems about the same to me. If it's positioned further from the eyepiece or camera and closer to the telescope objective, the reduction factor increases. Images made with my ZWO 533 camera testing both show them to be essentially the same. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. With spring galaxy season here, I decided to pick up a couple more to compare in a head-to-head shoot out. Depending on the design of the telescope, they may require separate focal reducers if they require focal reducers at all. Reducer Lens .7x - EdgeHD 800 Learn More. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads 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. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. This telescope control software replaces the hand control and allows the user to remotely control their Celestron computerized telescope from their personal PC or laptop. Read our guide! ), but stars seemed a bit tighter and their colors were richer and more dramatic. This innovative software solves the time-consuming problem of trying to pinpoint the North Celestial Pole. Completely stuck, completely frustrated. 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. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. In both cases will end with a similar tfov. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. This superb fully multi-coated multi-element focal reducer takes advantage of the latest computer aided design techniques to achieve the highest standards of performance set by the brand leaders at a fraction of the cost. 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! Reducer - Corrector Learn More. To test this, I used three set-ups: 1. This focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. Thanks. That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. What is likely is that fatigue sets in, and also that as the targets move toward or a way from the meridian there will be changes for that reason alone. Celestron or Antares f/6.3 focal reducer for SCT? Powered by Invision Community. Michael 1 ronin Members 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. Still not sure what is the right gear for you? Antares or Celestron? The review is a subjective visual impression, which is interesting but not best evidence. They usually have a 2" barrel that slides into the telescope focuser. Our patented SkyAlign alignment technology makes setting up a computerized telescope simple, fast, and accurate. Also read the reviews here, including those at 4 stars. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. 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). Today, our world-class team of optical and electronic engineers continues to push the boundaries of technology. Rather than a direct side-by-side, I swapped the reducers so that I was using them on the exact same, well-collimated instrument. 3. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. Upon close inspection, it was clear that the housing of Antares assembled in Canada version was a little more substantial than the Celestron. Explore Scientific Keys to the Universe Sale. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. 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 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. Meade once made an f/3.3 focal reducer for SCT scopes. The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. The distances d1 andd2 can also be expressed in terms of the focal length of the focal reducer FR with the lens equation: Using Equation 2, Equation 1 can also be expressed in terms of d2: The focal reduction factor of the focal reducer depends on its focal length and its distance from the focal plane of the objective as shown by Equation 4: Again, for example, when the focal reducer is placed at the original focal plane of the objective, d1=0 and MR=1, which means there is no focal reduction. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. CPWI has an extensive object database, employs PointXP mount modeling, and more. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. One of the most important factors in a telescope is its transmissionthe percentage of light that reaches the focal plane. 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. They are reported as identical. Focus misses by about 1 turnof the focus knob.Here is my solution:Buy a shorter 1.25 visual back for my scope. 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. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. 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. 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. 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. SKU: CEL-94245. Despite never removing it no matter what I was looking at. They never really recovered from selling a few 15 years back with element reversed. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. Some are available in 1.25" barrel format but with C threads. Specially-designed focal reducers are available for use with these telescopes. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. 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. We only send interesting emails and will never sell your data. 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. 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. Read our 101 article or get in touch. 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. All Rights Reserved. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. Reducer Lens .7x - EdgeHD 1100 Learn More. Thanks guys, appreciate the feedback. Article Agena AstroProducts, 2019. No difference. This article explains the basics of how focal reducers work with an astronomy telescope. However, this also came at a cost, as the sky background in the Antares was slightly brighter. The Antares focal reducer comes in small box. Opticstar F6.3 Focal Reducer / Corrector. Well done. Never noticed any anomalies with this unit. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. 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. Please Log in to save it permanently. Fastar Technology allows imagers the option of drastically increasing the speed and sensitivity of their Celestron optical tube, allowing bright, detailed images with short exposures. The Celestron f/6.3 is ~150 compared to the Antares at ~70. Thks for that and its not for visual it for astrophotography. It was used strictly for imaging, not visual observing. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. Style: 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. 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). 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. Much to my surprise, swapping back and forth between the two correctors using all three diagonal configurations, I also could detect absolutely no change in reduction between the two reducers. I've looked through one from Meade and first impression was that it was like the Celestron version. For both imaging and visual observing, these reducers also improve image sharpness at the edge of the field by correcting for coma and field curvature. 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. It's highly unlikely that they could be so precisely identical unless they were. Also, the focusers of most Newtonians do not have enough in-travel to accommodate a focal reducer. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. 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. 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. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. All additional accessories mount onto the exterior/male threads. 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. 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. Figure 6 shows a 1.25" focal reducer from GSO configured with a ZWO ASI224MC camera. I found both to be very good. 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. Focal Reducer, 2", 0.7X. Turn it on and push Align. In about three minutes, youre ready to observe! Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. 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. For imagers using longer focal-length refractors and SCTs, especially when using smaller sensors that place less demand on the focal reducer, there are economical alternatives for focal reducers from manufacturers such as GSO, Agena, and Antares. The Buyer's Guide To Eyepieces at the top of the Eyepieces forum has a column for this spec. Check out our 2022 telescope buying guide here! Sign up to get exclusive deals, observing tips, and new product announcements. 3. 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. Stars in the corner of the image frame are indistinguishable between the Antares and the Celestron. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. Torazz Who cares? The stock Celestron visualback is just under 2 long. But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. 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. These 0.63x focal reducers were originally designed to optimize for an image circle to match 36mm x 24mm film or its digital equivalent for astrophotography. When using the diagonal, keep the field stops of the eyepieces under 20mm. These RC reducers cannot be used with other types of telescopes. . Watch this before you buy Celestron 8SE SCT, or a Focal Reducer or a Hyperstar 7,758 views Mar 28, 2018 145 Dislike Share Ray's Astrophotography 42.3K subscribers Note: I am not paid or. 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's EdgeHD reducers feature a custom 5 element optical design engineered to maintain the flat-field performance of our award-winning EdgeHD optical system. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! For this shoot-out, I used a standard Celestron C8 with Starbright coatings. Normal shipments will resume on Monday, March 6, 2023. nleash the full pointing accuracy of your Celestron computerized telescope with a specialized telescope control software suite. Just one question. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. All Rights Reserved. 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. But when not in the box or on the telescope, there is no cover for the other end. But in the end they both do pretty much the same thing and it sounds like any performance difference is subtle. 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. Copyright 2021 Stargazers Lounge 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). A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. That was fun. Field stop diameters are one of the specified specs of eyepieces. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. Yellow and orange members of open clusters stood out a bit more as the various stars displayed their individuality. 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. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. Orders placed over the weekend will be shipped on the following Monday. I've only used it a few times but it looks good to me. A focal reducer does just the opposite of a Barlow lens or focal extender. 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. It seems right to put some distance between the camera and the focal reducer, right? There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. Please note, orders placed after 10am on 2/28/2023 will be delayed. 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. October 11, 2010 in Discussions - Scopes / Whole setups. For the best experience on our site, be sure to turn on Javascript in your browser. 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. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. looks virtually identical, except for the lettering. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. 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. 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. For visual use, this means you get lower power with the same eyepiece and a wider field of view. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. 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. The Celestron f/6.3 is ~150 compared to the Antares at ~70. The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). When you said, "in some cases" a focal reducer also works as a flattener/corrector, are you saying that not all focal reducers are flatteners/corrector? . However, manufacturers virtually never provide this specification. Some refractors such the TeleVue Nagler-Petzval (NP), the Takahashi "FSQ", and the William Optics Redcat/WhiteCat 51 have inherently flat fields because of internal optical elements. 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. Enter it during checkout! Again, these focal reducers are often provided by the telescope manufacturer. Never used one, but read the reviews here that suggest a coating problem. The stars at the edge could be worse or better. 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. If used before or beyond the working distance, unwanted image distortion may result. Like many of us with SCTs, I have bought and sold a number of f/6.3 reducer/correctors over the years, and I have always been curious how they really stack up to each other. Try & buy if you like - usual mates rates. 2023 Celestron, LLC. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. Reducer Lens .7x - EdgeHD 925 Learn More. 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 don't know. The female end attaches to the rear cell of the telescope. It is recommended for . This fully multi-coated lens provides maximum light transmission with near full-field illumination. Place the plastic covers on the lens when not in use to reduce the dust collection. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. 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 .