I'm going with the Celestron. Go behind the scenes with Celestrons product development team and learn more about our award-winning and patented innovations. 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. 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. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. There will be no shipments on 3/1/2023, 3/2/2023, or 3/3/2023 (March 1st - March 3rd, 2023). Manish Panjwani has been an active amateur astronomer since before Halley's Comet last flew by our neighborhood. which looks like the same one. 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. Copyright 2003-2022 Agena AstroProducts. OPT Product Number: AE-SCTFR specifications Warranty 2 Year Warranty Works as advertised! The most popular accessories for your new telescope! The naming convention of SCT focal reducers is a little confusing. Article Agena AstroProducts, 2019. How does it look thats what matters. This is very impressive performance given how hard this problem is to mitigate in general. The most significant mechanical variation, however, is the quality and precision of the threading. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. I am new to these optic topics, and I want to ask you what happens with Masutov like SW or Celestron 4 or 7 inches. Sign up for a new account in our community. 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. The reduction factor MR can also be written in terms of d2 as: When the focal reducer is placed at the working distance, D, that is when d2=D, then the reduction factor MR is equal to the design reduction factor MRD: Equations (6) and (7) imply these important considerations: Most manufacturers do not publish the focal length of their focal reducers, so it is not usually possible to calculate the working distance and design reduction factor. No idea what the issue is. 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. 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. High power views will provide flatter fields all the way to the edge, both visually and photographically. This is the simplest way to attach your ASI121 to your telescope. I have the Japanese version and although I haven't used it in quite awhile, the views through it were superb with no internal reflections at all. 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. The same illumination you have at the edge of a 27mm field, the C8 has at the edge of a 38mm field. 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. Right off the bat, I was struck by how similar the two R/Cs were. Even though they may have been slightly dimmer, galaxies were a bit easier to tease out of the urban light soup I deal with. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. 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! 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. For the best experience on our site, be sure to turn on Javascript in your browser. They only publish the value of D, the working distance (sometimes called the back focus distance) and the design reduction factor MRD. Your mileage may vary. 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. If you place your camera at a different working distance, you will get a different reduction factor and perhaps unwanted distortion in the image. 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. 160K views 9 years ago This video is a complete overview of focal reducers and how they function applying to telescopes. This Antares 1.25" 0.5x focal reducer lens (tele-compressor) is used under the Orion brand name to thread into the nosepiece of Orion StarShoot Solar System cameras and StarShoot Deep Space Color Imaging Camera. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Request stock alerts and we'll let you know when the item is back in stock. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. The author finds differences in throughput and color balance, but then says he thinks the lenses are identical and he reaches his conclusions based on very long observing session. 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. looks virtually identical, except for the lettering. Focal reducers for many SCTs and their flat-field equivalents usually have a back-focus distance of 105mm. 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. 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. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. Optically, it consists of a four-element lens that is fully multi-coated for high contrast and resolution. All rights reserved. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Celestron or Antares f/6.3 focal reducer for SCT? Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Reducer Lens .7x - EdgeHD 800 Learn More. However, manufacturers virtually never provide this specification. 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. Images in the Celestron tended to appear ever-so-slightly dimmer (maybe? That was fun. because they really dont matter. The distance d2, which measures the position of the new focal plane of the objective from the back of the focal reducer is given by Equation 5: In these equations, d1, d2, and MR are all variables that depend on each other through Equations 2 and 4. I have the Antares and have no complaints. Download the Celestron PWI Telescope Control Software. Fortunately, my neighbors are not out in their backyards at 11 pm, or they may have thought I was torturing a small mammal. Equation (4) shows the relationship between the distance d2 and the reduction factor MR. More details are found in the Appendix of this article. One focal reducer will not achieve optimum results with all types of telescopes, so there is no universal' focal reducer. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet. What I do know is that the Antares and the Celestron samples that I have perform exactly the same from the center right out to the edges. Any comments gratefully received. For me the Antares was a little brighter and had the least scatter by a bit so the better coatings won. In many cases, the answer is yes, especially for electronically-assisted astronomy (EAA). 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 filter threads on to the rear cell of your Celestron or Meade SCT telescope. Focal reducers are essential optical accessories for astrophotography, electronically-assisted astronomy (EAA), and in some cases, for visual observation with long focal ratio telescopes. Also read the reviews here, including those at 4 stars. Theres a long-running debate in these forums and even statements from some reputable dealers that the Antares is just a reducer (even though it is labeled Reducer/Corrector), whereas the Celestron is a true R/C, which flattens the SCTs naturally curved field and provides some edge correction. Nowadays I tend to use the Celestron more with my refractors for imaging and viewing. This should not be the case if they have their purportedly different focal lengths. 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 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. Your price: $579.00. 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. 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. For imagers, the main purpose of a focal reducer is to increase the brightness of the image at the focal plane. In your opinion, is the Celestron is worth the added cost ($150 vs. $90)? How about for visual observers? He received his first telescope at the age of 5 and completed his first university course in astronomy at the age of 12, eventually receiving a master's degree in the subject. a Tele Vue Panoptic), or a Plossl eyepiece with an apparent field of view of 50 and a focal length of 32mm. Reproduction without permission prohibited. Performance wise what differences might there be using the reducer on a smaller scope. In terms of reduction and correction - which are what reducer/correctors are supposed to do - both are superb. This innovative software solves the time-consuming problem of trying to pinpoint the North Celestial Pole. 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.
Cherokee Nation Higher Education, Peter Perpignano Obituary, Articles A