looks virtually identical, except for the lettering. Reducer - Corrector There are also third-party vendors such as Hotech. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. It's highly unlikely that they could be so precisely identical unless they were. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. Once installed, you can add additional accessories like T-Adapters, 1.25 Visual Back, Star Diagonal, or Off-Axis Guider. I even lost track of which reducer I was using. 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). In such cases, we will be happy to take the item back as per our standard return terms. These reducers have a back focus (or design working distance) of 80mm. 3. 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. This is a. I'd favor the Japanese Celestron version over the others that are commercially available. Meade once made an f/3.3 focal reducer for SCT scopes. A slight nod to the Antares for heft and higher transmission, but points to the Celestron for nice threads and better contrast. They usually have a 2" barrel that slides into the telescope focuser. I have both the Antares and the Celestron reducers. Please note, orders placed after 10am on 2/28/2023 will be delayed. This fully multi-coated lens provides maximum light transmission with near full-field illumination. Because I have not heard any complaints about the made in China R/C. Explore Scientific Keys to the Universe Sale. . If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. Try & buy if you like - usual mates rates. USD $80.00. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. Hi. Most reducers have a design reduction factor, MRD, that assumes the reducer is placed at a specific working distance, D, from the back surface of the focal reducer itself. By We reserve the right to verify a competitor's advertised price and the availability of the item. Things change but when I rebought I got an Antares and it seems about the same to me. 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. This appendix summarizes how this works based on simple equations from the book Telescope Optics by Rutten and van Venrooij. The Reduction Factor and the Amount of Reduction are inversely related. Or, when the distance of the focal reducer to the focal plane of the objective d1 equals the focal length of the focal reducer FR, the reduction factor MR = 0.5x. 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. No difference. I use the same back spacing for both on a small 6" Celestron SCT. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so. 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. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. JavaScript seems to be disabled in your browser. CPWI has an extensive object database, employs PointXP mount modeling, and more. The price for an item/offer must be listed and valid at the time of match. More aggressive reduction, or using these reducers with larger sensors, will result in aberrations and distortions near the edge of the image. Unleash the full pointing accuracy of your Celestron computerized telescope with a specialized telescope control software suite. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. I was originally hoping to do this with a made in Japan Celestron, but ended up with a newer China version but thats probably better in the end since it is the version now available, with the Japan ones rarer and only available used. 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. Field stop diameters are one of the specified specs of eyepieces. Weasner's Meade and Antares Focal Reducers Review A few large telescopes and mounts are excluded from this free shipping offer. 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. Many focal reducers are meant to be used within a few millimeters of the specified working distance to achieve the best possible image results. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. Several functions may not work. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. 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. Oceanside Photo & Telescope wants our customers to shop with confidence knowing that you will always get the best deal available. 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. Regardless, the difference was miniscule and is more than adequate on both and exceeds a 8 or 6 SCTs baffle tube diameter. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. When using the diagonal, keep the field stops of the eyepieces under 20mm. Images in the Celestron tended to appear ever-so-slightly dimmer (maybe? F6.3 Focal reducer for F/10 or higher telescopes, 43mm aperture, 4-Element, Fully Multicoated. For visual use, this means you get lower power with the same eyepiece and a wider field of view. 800-483-6287 In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. 2. Reducer - Corrector | Celestron Orders placed after 12:00 PM Pacific Time will be shipped the next business day. Some third-party vendors also make reducers for SCT scopes. Celestron or Antares f/6.3 focal reducer for SCT? I focus using a moonlight electronic focuser and focusmax. Nebula Filters. Designed distancing using the reducer with a 1.25 visual back and 1.25 Televue mirror diagonal; Antares or Celestron? Telescope Focal Reducers & Correctors - High Point Scientific How does it look thats what matters. But I am rusty, can you condense a bit for me please? I use the Celestron version and it seems OK for both visual and imaging. 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. At least these two units I tested make the answer - whatever. 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. A longer effective focal length leads to higher magnification with a given eyepiece for visual observers. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. They only publish the value of D, the working distance (sometimes called the back focus distance) and the design reduction factor MRD. What an enjoyable read and detailed comparison. Hello! 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. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. Read our 101 article or get in touch. ), 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. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. 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. 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. More important, its clear that the Antares is a reducer/corrector, just like the Celestron and not merely a reducer. 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). The lens that the ZWO comes with give a perfect wide angle image of what is in front of it. Reproduction without permission prohibited. 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. They are reported as identical. A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. Most Feather Touch focusers cost between $300-$350. It must be in stock at the time of Price Match for us to make a guarantee. 3. No retailers currently carry this product. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? 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. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. I don't know. Celestron or Antares f/6.3 focal reducer for SCT? In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. Reducer Lens .7x - EdgeHD 1400 Learn More. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. For the best experience on our site, be sure to turn on Javascript in your browser. 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. You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. The visual back must be removed first. More about this below. These reducers can also be used for visual observing with SCT scopes with eyepieces with a field stop as large as 24-27mm. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Some coma is visible in the corners, but the image is quite good for EAA applications. control and Sky Viewer display makes selecting your target easy. Right off the bat, I was struck by how similar the two R/Cs were. However, these will not impact optical performance. If I had to guess, the difference is maybe 10-15 grams. Have a promo code? Photographically you also get a wider field and much shorter exposures. 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. Best evidence would by obtained by using a camera and evaluating the image both by eye and with a computer analysis. Today, our world-class team of optical and electronic engineers continues to push the boundaries of technology. Looking forward to the day when I can do a shoot-out between a Japan and China Celestron, just for kicks. Besides observing from his heavily light polluted backyard in Los Angeles, Manish enjoys conducting astronomy outreach programs in local schools. Newtonian reflectors will seldom be able to accommodate the in-focus travel demanded by focal reducers. Opticstar F6.3 Focal Reducer / Corrector. The Antares f6.3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6.3. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. (Note: Using the simple equations above, the focal length of this reducer can be estimated to be about 350mm). 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. because they really dont matter. 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. 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. Fumbling around in the dark, fine threads might be a problem. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. Thanks Peter! And, the reality is that every F/6.3 RC out there Celestron, Hirsch, Astromania, etc., etc. Michael 1 ronin Members 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. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. We have corrected # (iii) after equations 6 & 7. We will be glad to help. 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. Since the focal length of the reducer, FR, is fixed, as d2 increases then MR decreases. Reducer Lens .7x - EdgeHD 925 My Celestron was made in China and the Antares in Canada. So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. 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. 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. Many Ritchey-Chretien telescopes available today are made by GSO. My experience is that CN sellers are way above those listing elsewhere. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. Learn more about extra solar planets imagery, 3D Star rendering, observation planning, telescope control, multiple-panel printing, and much more. This is very impressive performance given how hard this problem is to mitigate in general. Request stock alerts and we'll let you know when the item is back in stock. 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 . A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. 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. 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. 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 used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. Celestron is considered better in terms of QA, less likely to come with free dust, hair or fingerprint. . Thanks for pointing this out. The naming convention of SCT focal reducers is a little confusing. 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. 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. 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. Sharpness is essentially the same. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. Get ready for a night of astroimaging with your mount faster than previously thought possible with All-Star Polar Alignment. 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. Obviously bright objects like Jupiter or The Moon show the reflections. Using these numbers in equation 4 in the Appendix, below, we can easily calculate that the focal length of this unit is approximately103mm (it will be 103mm plus the small amount by which the rear lens surface of the reducer is recessed beneath the reducer housing). 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. But when not in the box or on the telescope, there is no cover for the other end. 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. All rights reserved. However, some focal reducers can be used on other models of telescopes, but this is not always possible. 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. Nada. 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. 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. Stars in the corner of the image frame are indistinguishable between the Antares and the Celestron. Focal Reducer, 2", 0.7X - Antares It is recommended for . Can these economical focal reducers from GSO and other vendors result in good images?
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