Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. InternetSales@optcorp.com, 800-483-6287 Well done. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. 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. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. 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. That said any comparison reviews are helpful. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. Sign up to receive sale alerts, news about upcoming celestial events, and telescope tips from our experts! Stars had a tiny bit more sparkle and pop. Given the results of Test #1, I wanted to see if there was any truth to this assumption. We have tested our current batch and it works with Meade, Celestron, and Baader SCT accessories. 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. 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. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. Here, there was a subtle difference . These reducers have a back focus (or design working distance) of 80mm. Again, these focal reducers are often provided by the telescope manufacturer. The Celestron f/6.3 is ~150 compared to the Antares at ~70. 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"). * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. This rugged, 3-in-1 device features a true tactical 3-mode flashlight, a hand warmer, and a portable power bank for recharging your personal electronics on the go. Most amateur astronomers are familiar with a Barlow lens (or a focal extender), a negative or diverging lens that effectively increases the focal length and the focal ratio of a telescope's objective lens. Things change but when I rebought I got an Antares and it seems about the same to me. Add a 0.63x reducer, and the brightness of extended objects increases by (1/0.63)2 = 2.5. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. By 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. It's usually specified in millimeters. Check out our 2022 telescope buying guide here! The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. Focal Reducer, 2", 0.7X. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. In practice, it's important to remember that you will rarely operate at the exact working distance and at the exact reduction factor that is specified. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. Hello! Focal Reducer for SCT - ACF - Stargazers Lounge 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. Read our 101 article or get in touch. In both cases will end with a similar tfov. October 11, 2010 in Discussions - Scopes / Whole setups. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. Melotte 15 - First Process in PixInsight (easy! Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. Celestron & Antares f/6.3 Reducer/Corrector Shoot-out 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. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. Please re-enable javascript to access full functionality. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. What an enjoyable read and detailed comparison. 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. Antares f/6.3 SCT Focal Reducer - Rother Valley Optics Ltd The female end attaches to the rear cell of the telescope. Reducer Lens .7x - EdgeHD 925 Learn More. 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. 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. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. . We tested GSO's 1.25" 0.5x focal reducer at a variety of operating distances and calculated the field of view through a telescope to derive the actual reduction factor that is plotted below. I had a Celestron, Antares and Hirsch for awhile and compared them over about a year. It features a standard male SCT thread (2" OD, 24 TPI) on one side and a standard SCT female thread on the other. Celestron or Antares f/6.3 focal reducer for SCT? 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. The lens is housed in machined aluminum for are machined aluminum black anodized. They only publish the value of D, the working distance (sometimes called the back focus distance) and the design reduction factor MRD. We have corrected # (iii) after equations 6 & 7. Powered by Invision Community. Enter it during checkout! 3. The resultant reduction factor was measured to be 0.46x. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). JavaScript seems to be disabled in your browser. The threads were similar on the eyepiece end, but a bit smoother. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. 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. Newtonian reflectors will seldom be able to accommodate the in-focus travel demanded by focal reducers. However, manufacturers virtually never provide this specification. For the best experience on our site, be sure to turn on Javascript in your browser. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. Thanks Peter! 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. No retailers currently carry this product. Please let us know what topics you are interested in. 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. Bear in mind you can't squeeze blood out of a turnip, i.e. For visual use, this means you get lower power with the same eyepiece and a wider field of view. Field stop diameters are one of the specified specs of eyepieces. Reducer - Corrector 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. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. 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. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. 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. 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. The naming convention of SCT focal reducers is a little confusing. Sharpness is essentially the same. This award-winning optical system reduces visual defects like field curvature and coma, creating an ultra-flat field for pinpoint stars all the way to the edge of todays largest imaging sensors. 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. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. control and Sky Viewer display makes selecting your target easy. Using this same example of an 8" SCT and a 0.63x reducer, a visual observer can also enjoy brighter images and a wider field of view. In such cases, we will be happy to take the item back as per our standard return terms. 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. If you do so, you will achieve the design reduction factor. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. Meade once made an f/3.3 focal reducer for SCT scopes. 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. The Reduction Factor and the Amount of Reduction are inversely related. Can these economical focal reducers from GSO and other vendors result in good images? Does anyone have any experience with the Celestron and Antares focal reducers? Antares f/6.3 Focal Reducer for SCTs - Awesome Astro Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. So, this past week I challenged the Antares and Celestron models to a head-to-hear on my C8 on some decent nights of good seeing and transparency in my Bortle 5-6 urban skies. These scopes are compatibles with focal reducers. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. 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. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. 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 Celestrons aplanatic EdgeHD optics revolutionized astroimaging. 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. The two samples I have PERFORM IDENTICALLY. Michael 1 ronin Members I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. Clearly cost is a big factor for satisfied users. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. We reserve the right to verify a competitor's advertised price and the availability of the item. CEL-94245. The working distance or required back focus, explained above, is usually specified and is far more important in practice. 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. Back-Focus 101: DSLR Cameras & the Celestron f/6.3 Reducer - YouTube They are also less expensive than many external focusers of similar build quality. The reducer fits all Meade and Celestron . Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. 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. Antares Click Lock Visual Back - Cats & Casses - Cloudy Nights As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. To calculate how much back focus spacing you need to add, take the thickness of the filter and divide it by 3. Observing the microscopic world has never been easier! Contiguous US Customers:All items we sell ship for free within the Contiguous US. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. But when not in the box or on the telescope, there is no cover for the other end. Also read the reviews here, including those at 4 stars. . There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). None of this was offensive, nor did it interfere with views in any significant way. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. Possibly the design of the Antares was changed .. 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. Each focal reducer has a fixed specification called the working distance or required back focus. The stock Celestron visualback is just under 2 long. How to Set the Correct Back Focus for Your Telescope (Guide) Sky recognition technology that has revolutionized the manual telescope by eliminating the confusion common among beginners and enhancing the user experience for even seasoned telescope users. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. 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. How does it look thats what matters. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. The nominal design reduction factor of these reducers is typically 0.5x. 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. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. Now It only focuses near things, like some kind of macro zoom. He tested this on an 8 Celestron , I have a Celestron 6SE. 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. Any comments gratefully received. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? 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. If I had to chose one, I would base my decision on your level of light pollution perhaps the Antares for its slightly higher transmission if you live under less light polluted skies, but the Celestron for its greater contrast if you are dealing with a suburban or urban light dome. 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. Turn it on and push Align. In about three minutes, youre ready to observe! The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. A reducer is a set of converging (or positive) lenses that cause the light from a telescope objective to converge at a steeper angle to the focal plane as if it were coming from an objective with a faster (lower) focal ratio and a shorter focal length. 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. which looks like the same one. This filter threads on to the rear cell of your Celestron or Meade SCT telescope.
antares vs celestron focal reducer