It seems right to put some distance between the camera and the focal reducer, right? Because most modern Newtonians already have relatively fast focal ratios, these telescopes do not usually use focal reducers. Explore Scientific Keys to the Universe Sale. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. 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. It was used strictly for imaging, not visual observing. 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. 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. 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. He also holds a Ph.D. in engineering physics from McMaster University. Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. 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 working distance of the GSO 0.5x focal reducer with 1.25" barrel and the GSO 0.5x focal reducer with 2" barrel is about 51mm to 53mm, approximately, from the middle of the metal cell that holds the lens. CPWI has an extensive object database, employs PointXP mount modeling, and more. Many Ritchey-Chretien telescopes available today are made by GSO. Possibly the design of the Antares was changed .. Not a bit. Not noticed any optical problems. So it provides a 0.63x design reduction factor when used with an f/10 SCT at the specified working distance. Never used one, but read the reviews here that suggest a coating problem. 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. 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. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. Equation (4) shows the relationship between the distance d2 and the reduction factor MR. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. If used before or beyond the working distance, unwanted image distortion may result. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. 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. 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. ), 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. This would tell us exactly how well aberrations are corrected. More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. 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. Copyright 2021 Stargazers Lounge Contiguous US Customers:All items we sell ship for free within the Contiguous US. 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. 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. 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. It features a standard male SCT thread (2" OD, 24 TPI) on one side and a standard SCT female thread on the other. Turn it on and push Align. In about three minutes, youre ready to observe! 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. They usually have a 2" barrel that slides into the telescope focuser. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Sharpness is essentially the same. Figure 2 shows the effective of a focal reducer on the light from a telescope objective. 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. 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. Reducer Lens .7x - EdgeHD 1400 Learn More. With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. Over the course of a several nights of general observing, I swapped back and forth between the Antares and Celestron R/Cs on a wide variety of objects open clusters, brighter galaxies, a couple of nebulae, and globular clusters as well. 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. Can these economical focal reducers from GSO and other vendors result in good images? This is a. Orders placed after 12:00 PM Pacific Time will be shipped the next business day. The most significant mechanical variation, however, is the quality and precision of the threading. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. 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. 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 must be in stock at the time of Price Match for us to make a guarantee. He tested this on an 8 Celestron , I have a Celestron 6SE. control and Sky Viewer display makes selecting your target easy. 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. However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. The previous post shows the reducer on what appear to be two different refractors. 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. Melotte 15 - First Process in PixInsight (easy! I focus using a moonlight electronic focuser and focusmax. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. The Antares focal reducer comes in small box. Copyright 2003-2022 Agena AstroProducts. Reproduction without permission prohibited. 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. WiFi technology encircles the globe in a web of connectivity, knowledge, and information. 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. Meade once made an f/3.3 focal reducer for SCT scopes. You need to be a member in order to leave a comment. I have an 8SE, and am thinking about getting a focal reducer. The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. . That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. Perfect for the serious student, professional scientist and discriminating hobbyist. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing). 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. If the reducer is placed closer to the eyepiece or camera than the distance D, the reduction factor decreases. You attach the focal reducer to the rear port on a SCT and can keep it covered. Here, there was a subtle difference . It is not a corrector or flattener. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. But while the image gets brighter, the size of the image circle gets proportionately smaller. This should not be the case if they have their purportedly different focal lengths. 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! Celestron makes a series of focal reducers for the Edge HD line that are matched to the 8", 9.25", 11", and 14" apertures of these scopes. I doubt there is any difference between the Antares and the Celestron except price. The most popular accessories for your new telescope! This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. Obviously bright objects like Jupiter or The Moon show the reflections. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. I only have the Celestron f/6.3. In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? It threads onto the rear cell of 5" to 16" Celestron and Meade Schmidt-Cassegrain telescopes, making it possible to have a dual focal ratio instrument without sacrificing image quality. This was most noticeable on the eyepiece end of the RC, where the metal rim surrounding the lens was about 1mm thicker than on the Celestron. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. I have the Antares and have no complaints. 2023 Celestron, LLC. 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. 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. I have had the Japan unit on the back of my C5 since 1994 or thereabouts. 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. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. 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. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. CEL-94245. Antares or Celestron? This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. InternetSales@optcorp.com, 800-483-6287 The Celestron f/6.3 is ~150 compared to the Antares at ~70. 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. They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. Thank you so much for the informative article, I now understand better how to integrate my reducer into my system to get better performance. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. All additional accessories mount onto the exterior/male threads. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. Does anyone have any experience with the Celestron and Antares focal reducers? Orders placed over the weekend will be shipped on the following Monday. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? 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. A focal reducer does just the opposite of a Barlow lens or focal extender. The lens that the ZWO comes with give a perfect wide angle image of what is in front of it. Also, the focusers of most Newtonians do not have enough in-travel to accommodate a focal reducer. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. Wonder how they would stack up with a Japanese 6.3. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. 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. The most commonly available focal reducers for SCTs are the f/6.3 reducers from Celestron and a similar f/6.3 focal reducer from Meade. 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. Celestron or Antares? In both cases will end with a similar tfov. 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. 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. 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). Unique focal reducer and field corrector lens accessory Reduces the focal length and f/ ratio of your Schmidt-Cassegrain telescope by 37% Provides a dual focal ratio instrument, without sacrificing image quality Compatible with all Schmidt-Cassegrain telescopes (see compatible list in description) Share Customers Also Purchased Description I have this one Opticstar F6.3 Focal Reducer / Corrector. I wish there was. 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. Reducer Lens .7x - EdgeHD 1100 Learn More. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. Style: But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. Sign up to get exclusive deals, observing tips, and new product announcements. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? As one increases, the other decreases. 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. Again, these focal reducers are often provided by the telescope manufacturer. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. 3. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. 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! 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. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. I found both to be very good. 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 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. 2. If you do so, you will achieve the design reduction factor. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. I'd favor the Japanese Celestron version over the others that are commercially available. In such cases, we will be happy to take the item back as per our standard return terms. 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%.