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No idea what the issue is. For me, I was looking for, and planning to keep, the one that yielded the greatest reduction. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. This is very impressive performance given how hard this problem is to mitigate in general. The Celestron f/6.3 is ~150 compared to the Antares at ~70. Reproduction without permission prohibited. But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. Sign up to get exclusive deals, observing tips, and new product announcements. The Antares is supposed to be pretty comparable. Sign up for our newsletter to get exclusive deals, observing tips, and new product announcements. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. 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. That includes, for example, a 1.25" eyepiece with an apparent field of view of 68 and a focal length of 24mm (eg. It's highly unlikely that they could be so precisely identical unless they were. High power views will provide flatter fields all the way to the edge, both visually and photographically. A focal reducer does just the opposite of a Barlow lens or focal extender. It is recommended for . We will match any online price that we confirm as valid. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Unleash the full pointing accuracy of your Celestron computerized telescope with a specialized telescope control software suite. Download the Celestron PWI Telescope Control Software. Maybe I got a lemon. This filter threads on to the rear cell of your Celestron or Meade SCT telescope. Have always disliked the crude, noisy SCT threads, but I get it. Again, to my surprise, there was absolutely no difference between the Celestron and Antares on any star. With the barrel 1.25 reducer won't focus, all I get is fuzzy snowballs. I think that the FRs made in Japan in the day may have been better. But is there a difference in quality between the Antares and the Celestron or Meade focal reducers? But when not in the box or on the telescope, there is no cover for the other end. If you want to save a few buck watch the classifieds on CN. 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%. 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. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. Generally, views through the Antares seemed a little more transparent and brighter. The price for an item/offer must be listed and valid at the time of match. . In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? A useful thing to know is how far from the objective lens (for a refractor) is the focal reducer located. looks virtually identical, except for the lettering. More about this below. 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. 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. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. Reducer Lens .7x - EdgeHD 1400 Sharpness is essentially the same. I would not use the reducer with a 2" diagonal or eyepiece in the C6. Better images are also obtained when using these focal reducers at a reduction factor of 0.5x 0.8x, approximately. 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. 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. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. Clearly cost is a big factor for satisfied users. Yellow and orange members of open clusters stood out a bit more as the various stars displayed their individuality. Completely stuck, completely frustrated. He tested this on an 8 Celestron , I have a Celestron 6SE. It's usually specified in millimeters. I'd favor the Japanese Celestron version over the others that are commercially available. This means that there must be sufficient travel on the telescope focuser to make up for this. 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. Sign up to receive sale alerts, news about upcoming celestial events, and telescope tips from our experts! It's easy! This filter threads on to the rear cell of your Celestron or Meade SCT telescope. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. Copyright 2003-2022 Agena AstroProducts. 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. The reducer features fully coated optics in an anodized aluminum filter ring with an ergonomic rubber grip. Take control of your telescope! Celestron or Antares f/6.3 focal reducer for SCT? Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? 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. This also resulted in the clear aperture of the Antares being about 39-39.5mm, versus the Celestrons 41mm. Our proprietary StarBright XLT optical coatings dramatically increase transmission, up to 97.4% on our Schmidt corrector lenses. They usually have a 2" barrel that slides into the telescope focuser. ), 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. Since the Celestron and Antares are supposed to have different focal lengths and spacing specs, I expected different results. Hmmm . 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. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. Yet, the Antares still easily and fully threaded without any hitches. During checkout, you may also be shown other optional faster shipping choices.US Customers in Hawaii and Alaska: Free shipping applies to almost all products. 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. 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. 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. Will not focus with the stuff I have. Request stock alerts and we'll let you know when the item is back in stock. 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. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). Field stop diameters are one of the specified specs of eyepieces. Community Forum Software by IP.BoardLicensed to: Cloudy Nights, E of San Francisco Bay and W of the Awahnee, This is not recommended for shared computers, reviews here that suggest a coating problem, Back to Celestron Computerized Telescopes, Looking for advice on first refractor and camera. With both, using the same diagonal set-up, the exact same stars were visible at the very edge of the FOV. The Antares focal reducer comes in small box. 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. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. Explore Scientific Keys to the Universe Sale. Wow, that is a very detailed discussion! 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. For the best experience on our site, be sure to turn on Javascript in your browser. I really don't see any difference in the current crop except the "Meade" is usually the cheapest. Despite never removing it no matter what I was looking at. which looks like the same one. Thanks for pointing this out. They are reported as identical. Hi. If yes, what kind of focal reducers can I use? However, I noticed immediately that the Antares had a bit more of an heft to it, giving it a solid feel the Celestron didnt possess. Bear in mind you can't squeeze blood out of a turnip, i.e. Again, these focal reducers are often provided by the telescope manufacturer. I was referring to the C6 to answer you specifically. Please note, orders placed after 10am on 2/28/2023 will be delayed. As mentioned in Section 2.3, the reduction factor for these focal reducers can be varied by adding spacers to move the reducer further from the camera sensor or eyepiece. 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. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. Most refractor manufacturers such as William Optics, Tele Vue Optics, Explore Scientific, Sky-Watcher, William Optics, and Stellarvue make their own focal reducers optimized for use with their telescopes. The more focal reduction, the further inward the focal plane will be. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. Powered by Invision Community. CPWI has an extensive object database, employs PointXP mount modeling, and more. 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 Antares FR2-0.7X is the same 4-element f/6.3 lens system used for f/10 Schmidt-Cassegrain telescopes but in a 2" barrel threaded for standard filters. Opticstar F6.3 Focal Reducer / Corrector. My experience is that CN sellers are way above those listing elsewhere. Right off the bat, I was struck by how similar the two R/Cs were. I must admit, as well, that I no longer place a lot of stock in the notion that Chinese optics are inferior to Japanese or Taiwanese any longer, as manufacturing technology has really leveled the playing field today, with most Chinese optics being excellent. Brian Ventrudo is a writer, scientist, and astronomy educator. Perfect for the serious student, professional scientist and discriminating hobbyist. Thks for that and its not for visual it for astrophotography. Never noticed any anomalies with this unit. More details are found in the Appendix of this article. Turn it on and push Align. In about three minutes, youre ready to observe! Each focal reducer has a fixed specification called the working distance or required back focus. So ab6110 is asking for a FR only without coma correction, there are a couple of brands who make special reducers for the ACF. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. Stars had a tiny bit more sparkle and pop. - thanks. Thanks. Many Ritchey-Chretien telescopes available today are made by GSO. Many reducers, such as the Celestron HD focal reducer mentioned above, and many focal reducers for apochromatic refractors, are meant to be used within a few millimeters (or less) of the specified working distance to achieve the best possible image results. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. 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. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss. Unlike SCT telescopes, Ritchey-Chretien telescopes and Celestron Edge HD or Meade ACF scopes have internal optics that provide an inherently flat field, so these telescopes require a special focal reducer than does not provide additional correction for field curvature. If you want to use them for visual - try maybe long focal length eyepieces rather than the reducer. There are also third-party vendors such as Hotech. For the best experience on our site, be sure to turn on Javascript in your browser. Assuming you use the reducer with the stock 1.25" diagonal, it will operate at f/6.3. In terms of reduction and correction which are what reducer/correctors are supposed to do both are superb. EclipSmart solar products feature Solar Safe filter technology providing the ultimate protection from harmful solar radiation, including both IR and UV light, and filters 99.999% of visible light. Reducer Lens .7x - EdgeHD 925 Fumbling around in the dark, fine threads might be a problem. 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. They only publish the value of D, the working distance (sometimes called the back focus distance) and the design reduction factor MRD. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. We have corrected # (iii) after equations 6 & 7. We do not price match competitors if they are out of stock. Reducer - Corrector Learn More. The reducer is we might presume designed to correct to some as yet un-measured extent, the image of a standard SCT. 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! ED glass is specially formulated and contains rare-earth compounds that greatly reduce a visual defect called chromatic aberration. 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. 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? Is that distance D= Fo-d1=Fo-(d2/MR)? Michael 1 ronin Members Rather than a direct side-by-side, I swapped the reducers so that I was using them on the exact same, well-collimated instrument. Most Feather Touch focusers cost between $300-$350. 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. The problem with those SCT reducers is that they cause chromatic aberration and require refocusing when using parfocal RGB/other filters. No rainchecks will be issued for items out of stock at OPTcorp.com to match a competitor's price. We reserve the right to verify a competitor's advertised price and the availability of the item. Therefore, a 55mm back focus with a filter that is 3mm thick added to the imaging train would become 56mm. However, these will not impact optical performance. While most Barlow lenses and focal extenders work with most kinds of telescopes available to amateur astronomers, focal reducers are designed to work in a narrow range of focal ratios of a telescope objective. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. For Stephen Wilkerson: The ZWO ASI120MC-S does come with a wide angle lens, HOWEVER, it is NOT intended to used when you are using the ASI120 camera attached to your telescope. This should not be the case if they have their purportedly different focal lengths. By using this site, you agree to our Terms of Use. Possibly the design of the Antares was changed .. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. In this case, an additional T-adapter (with an optical length of 50mm) is needed to get the spacing correct for a DSLR or other camera with a 55mm back focus. If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. Details: The item must be the identical item, brand name, size, weight, color, quantity and model number. With the Celestron Reducer/Corrector Lens, thats precisely what you get. 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. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads It has only one cover, which surprised me. Who cares? 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. I don't know. I have the Antares and have no complaints. 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. During check-out, you will be presented with several shipping choices and costs. Explicitly designed for Celestron Schmidt-Cassegrain telescopes, this unique lens reduces your telescopes focal length and f/ ratio by 37%, turning your long focal length telescope into a fast, short focal length instrument. I have the Antares and am not unhappy with it, but for AP I would want more back focal distance if those numbers are accurate. Unscrew that wide angle lens and put it away, then attach the ASI120 to the nose-piece that came with the camera and fit that into the eyepiece holder. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. And, the reality is that every F/6.3 RC out there Celestron, Hirsch, Astromania, etc., etc. The key points are as follows: So just remember that a smaller distance (from the camera or eyepiece) means a lower amount of reduction (and vice versa). Enter it during checkout! October 11, 2010 in Discussions - Scopes / Whole setups. The faster f/ratio allows you to use slower film or shoot in lower light level situations and still properly expose your subject. The focal length of a focal reducer is usually measured from the rear lens surface of the reducer (and not the reducer's housing).