antares vs celestron focal reducer antares vs celestron focal reducer

That was fun. 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. 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. 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. 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 . 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. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer. Focal Reducer, 2", 0.7X. InternetSales@optcorp.com. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). 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. 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. Advanced designs for Schmidt-Cassegrain scopes such as the Meade ACF or Celestron Edge HD have optical elements in the tube to correct for coma and field flatness. Reducer Lens .7x - EdgeHD 800 When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. Please let us know what topics you are interested in. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. I'd favor the Japanese Celestron version over the others that are commercially available. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. The resultant reduction factor was measured to be 0.46x. 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. There may have been an almost imperceptible difference, but the Antares and Celestron were producing precisely the same reduction. 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. All additional accessories mount onto the exterior/male threads. All rights reserved. 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. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. 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. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. It was used strictly for imaging, not visual observing. Newtonian reflectors will seldom be able to accommodate the in-focus travel demanded by focal reducers. Sign up for OPT news, exclusive offers, and updates on the latest gear! Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. Photographically you also get a wider field and much shorter exposures. Take control of your telescope! For the best experience on our site, be sure to turn on Javascript in your browser. 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. However, this also came at a cost, as the sky background in the Antares was slightly brighter. Place the plastic covers on the lens when not in use to reduce the dust collection. Wonder how they would stack up with a Japanese 6.3. You may need spacers or a T-adapter to ensure the correcting working distance. 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. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. Most Feather Touch focusers cost between $300-$350. control and Sky Viewer display makes selecting your target easy. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. Equation 6 & 7 item two & three does not make sense, both say increase its reduction (one should say reduce its reduction?). Obviously bright objects like Jupiter or The Moon show the reflections. As mentioned in Section 2 of this guide, the reduction factor of a focal reducer depends on its position in the optical path relative to the eyepiece or camera. Yellow and orange members of open clusters stood out a bit more as the various stars displayed their individuality. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. 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. More about this below. That is definitely a 2" eyepiece, but it is not a large or long focal length 2" eyepiece. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; The price for an item/offer must be listed and valid at the time of match. Can these economical focal reducers from GSO and other vendors result in good images? Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. Bear in mind you can't squeeze blood out of a turnip, i.e. My experience is that CN sellers are way above those listing elsewhere. It has only one cover, which surprised me. 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. A focal reducer does just the opposite of a Barlow lens or focal extender. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? Not a bit. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? Copyright 2021 Stargazers Lounge For example, with a 0.8x focal reducer, a telescope with a focal length of 800mm will operate at 800 x 0.8 = 640mm when the reducer is placed at the working distance specified by the manufacturer. As a Barlow's magnification increases with increasing distance from the Barlow, a focal reducer's reduction increases with increasing distance from the reducer. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. 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. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions. In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. Well done. Have a promo code? Thanks for pointing this out. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. Focal reducers for many SCTs and their flat-field equivalents usually have a back-focus distance of 105mm. 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. 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? 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. Check out our 2022 telescope buying guide here! The Reducer/Corrector is easy to install by threading the unit onto the rear cell of your Schmidt-Cassegrain telescope (or the reducer plate of the C11 and C14). Many focal reducers are meant to be used within a few millimeters of the specified working distance to achieve the best possible image results. and you will be fine. Housings, threads, reduction, correction, blah, blah, blah. Reducer Lens .7x - EdgeHD 1100. Most manufacturers provide this specification. But nearly every observer who installs one of these devices is pleased with their performance. 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. That's partly because focal reducers correct for field curvature, which itself depends on the focal ratio and other optical design factors of the telescope. However, some focal reducers can be used on other models of telescopes, but this is not always possible. A few large telescopes and mounts are excluded from this free shipping offer. As another example,GSO makes focal reducers for their line of Ritchey-Chretien imaging telescopes. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. which looks like the same one. They are designed (assuming you are referring to the f/6.3 version) for the f/10 light cone. You don't need to follow these equations to use a focal reducer, but they do show how the reduction factor changes with the placement of the reducer. 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. There are many different types of focal reducers and they all effect. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. 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. And when used in some refractors, the field flattening is not as accurate as it is in the f/10 SCTs. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. If I had to guess, the difference is maybe 10-15 grams. First, let's have a look at some key optical parameters are needed to understand focal reducers. 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. Reviews. Here, there was a subtle difference . 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. 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! Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. I only have the Celestron f/6.3. 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 . Reducer Lens .7x - EdgeHD 1400 Learn More. The working distance or required back focus, explained above, is usually specified and is far more important in practice. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. Copyright 2003-2022 Agena AstroProducts. 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. 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. The Best Dedicated Astronomy Cameras for Beginners, Astronomik OIII 12nm CCD Filter - T-Threads, Pegasus Astro Dual Motor Focus Controller, 10 Micron 12kg (26.45lbs) Stainless Steel Counterweight- GM 2000, I would like more information regarding stock availability dates. No small animals were harmed in making these observations. Thanks Peter! Explore Scientific - Keys to the Universe Sale. 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. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. This article explains the basics of how focal reducers work with an astronomy telescope. 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. - thanks. 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. However, doesn't fit in the telescope and even if it did wouldn't work. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. SKU: CEL-94245. 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. He also holds a Ph.D. in engineering physics from McMaster University. Given past experience with them, I decided not to include the Meade version in my little experiment, as I have never met one I liked from getting one of the too-short focal length models, to one with some overflow cement in the doublet, to focus difficulties with some eyepieces. What an enjoyable read and detailed comparison. Any comments gratefully received. Copyright 2003-2022 Agena AstroProducts. . JavaScript seems to be disabled in your browser. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. To further factor out my natural astigmatism (I normally wear glasses while observing), I did the tests with my regular progressive lenses, single vision glasses I use when observing, and naked eye. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. For this test, I used a single configuration R/C, Click-lock, and 1.25 diagonal with the adapter. Sharpness is essentially the same. Your wishlist has been temporarily saved. The Celestron is both a corrector and focal reducer and the Antares is just a focal reducer. Getting the proper back-focus for your imaging camera is a vital step in getting the best data possible out of your telescope imaging/research rig. 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 and Celestron both sell such SCT-T adapters with the correct optical length. Hi. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. I would not use the reducer with a 2" diagonal or eyepiece in the C6. It's easy! The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for for those Astronomers on the go. How about for visual observers? The stock Celestron visualback is just under 2 long. How does it look thats what matters. Meade once made an f/3.3 focal reducer for SCT scopes. All Rights Reserved. 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. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. We have tested our current batch and it works with Meade, Celestron, and Baader SCT accessories. It's usually specified in millimeters. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. 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.