He tested this on an 8 Celestron , I have a Celestron 6SE. 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. On the trail, at the job site, in the classroom, or simply sitting at home relaxing the Celestron Elements ThermoTank 3 will keep your hands toasty. 2. Ive owned Celestron, Meade, and Antares models over the years at least a couple of each. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. Antares' f/6.3 focal reducer provides a faster f/6.3 system for imaging or visual use when used with an f/10 SCT or other compatible telescopes. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. Regardless, the difference was miniscule and is more than adequate on both and exceeds a 8 or 6 SCTs baffle tube diameter. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). The equations in the Appendix show how this all works. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA. Manish Panjwani has been an active amateur astronomer since before Halley's Comet last flew by our neighborhood. This part is no longer in production, but it is sometimes available used and may be used with cameras with smaller sensors. The easiest way to use a focal reducer is to make sure you place it at the specified working distance in front of your camera or eyepiece. This is the simplest way to attach your ASI121 to your telescope. 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. If used before or beyond the working distance, unwanted image distortion may result, especially when using cameras with larger sensors. The Reducer/Corrector can also be used for terrestrial digiscoping. 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. The Buyer's Guide To Eyepieces at the top of the Eyepieces forum has a column for this spec. Right off the bat, I was struck by how similar the two R/Cs were. You can probably eke out 1.2 without noticing serious vignetting, which is a field stop of 31.5mm. . The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. 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 have an 8SE, and am thinking about getting a focal reducer. 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. 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. Who cares? ), 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. Style: 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. Figure 2 shows the effective of a focal reducer on the light from a telescope objective. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Have always disliked the crude, noisy SCT threads, but I get it. There are many different types of focal reducers and they all effect. Please re-enable javascript to access full functionality. It is not a corrector or flattener. Stock focusers in an SCT move the mirror of the scope to change the position of the focal plane, and they have sufficient travel to accommodate a focal reducer. The equations and argument in the Appendix of this article shows the relationship between the working distance and the reduction factor. Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. Today, our world-class team of optical and electronic engineers continues to push the boundaries of technology. Easy solution found a very tiny dab of super lube on the threads and all was well and quiet.. In some cases, focal reducers also act as field flatteners by correcting for field curvature and coma of the objective lens. Sign up for OPT news, exclusive offers, and updates on the latest gear! 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. 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. Most focal reducers are designed to operate optimally at the working distance in the optical path to achieve their specified reduction factor, which is usually between 0.5x and 0.8x. 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. However, even though the imprint on the item states "Reducer / Corrector" please note that his is a reducer only. 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. Some faster refractors with a focal ratio of f/6, for example, only require field flatteners and not focal reducers. Most amateur astronomers are familiar with a Barlow lens (or a focal extender), a negative or diverging lens that effectively increases the focal length and the focal ratio of a telescope's objective lens. We have placed cookies on your device to help make this website better. Since then, Agena has become one of the leading online retailers of telescopes and astronomical accessories worldwide. Is there likely to be any differences in performance between using these on an 8 or something smaller like my 6SE? Because I have not heard any complaints about the made in China R/C. 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. 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. Reducer Lens .7x - EdgeHD 925 Learn More. Photographically you also get a wider field and much shorter exposures. Now, Celestron is using that same technology to allow star gazers to connect to the night sky and enhance their experience of the cosmos in fun and unique ways. Manish holds a Master's degree in Electrical Engineering from Virginia Tech and an MBA from the Kellogg School of Management at Northwestern University. That was fun. Whereas the Celestron threaded smoothly onto the scope, the Antares chattered and squeaked a bit more so when being removed. Celestrons award-winning Nature DX binocular gets a major upgrade with the addition of ED objective lenses. Copyright 2003-2022 Agena AstroProducts. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. Yet, the Antares still easily and fully threaded without any hitches. 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. When using the diagonal, keep the field stops of the eyepieces under 20mm. In the 1960s, Celestrons founder, Tom Johnson, created groundbreaking new telescopes never before seen on the consumer market. Telescope Optics, Rutten and van Venrooij, Chapter 15, Willman-Bell (1988). 800-483-6287 The resultant reduction factor was measured to be 0.46x. Some coma is visible in the corners, but the image is quite good for EAA applications. Reducer Lens .7x - EdgeHD 1100. Because of their distinct optical design, slower Schmidt-Cassegrain telescopes (SCT) with focal ratios of f/10 require a different design of focal reducer compared to refractors. As a result, the smaller tube may cut into the light cone and effectively reduce the working aperture of the telescope. For example, an 8" SCT without a focal reducer has an illuminated field of 38mm at 50% fall-off. With the Celestron Reducer/Corrector Lens, thats precisely what you get. which looks like the same one. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. However, the China 6.3 R/C has noticeable internal reflections that I haven't figured out yet. Brian Ventrudo is a writer, scientist, and astronomy educator. Hmmm . Request stock alerts and we'll let you know when the item is back in stock. Orders placed over the weekend will be shipped on the following Monday. In both cases will end with a similar tfov. 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. More details are found in the Appendix of this article. Your wishlist has been temporarily saved. 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. 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. USD $80.00. 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. * Not a Retail Store * 16313 Arthur StreetCerritos, CA 90703, USA, Availability: Item has been discontinued by Agena and we no longer carry this item. Possibly the design of the Antares was changed .. My experience is that CN sellers are way above those listing elsewhere. CEL-94245. Just point the telescope at any three bright objectsstars, bright planets, or even the Moonand your telescope can orient itself with the night sky. As I understand it, compared to the old Meade SCT's, the ACF is already "coma corrected", so the standard Meade, Celestron etc F6.3 focal reducers are not suitable and will only worsen the images. No results, please adjust your filters. No small animals were harmed in making these observations. Fortunately, my neighbors are not out in their backyards at 11 pm, or they may have thought I was torturing a small mammal. Focal reducers for these relatively fast ED refractors are generally for imaging only, not for visual observation. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. For example, a 0.8x reducer placed at the working distance provides a reduction of (1 0.8) x 100 = 20%. Please note, orders placed after 10am on 2/28/2023 will be delayed. 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 example, the focal reducer for an 8-inch Celestron EdgeHD telescope has a design reduction factor of 0.7x and a specified working distance (or back focus) of 105mm. These RC reducers cannot be used with other types of telescopes. I even lost track of which reducer I was using. Melotte 15 - First Process in PixInsight (easy! I have this one Opticstar F6.3 Focal Reducer / Corrector. Start Chat That means the base of the mounting threads of the focal reducer needs to be 55mm from the camera sensor to achieve the design reduction factor, which is usually 0.8x or 0.85x. Meade once made an f/3.3 focal reducer for SCT scopes. 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. Sharpness is essentially the same. 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. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. I wonder whether, for example, Antares focal reducer for SCT belongs to the latter category. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. 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. I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. Celestron or Antares f/6.3 focal reducer for SCT? But the diameter of the image circle decreases by a factor of 0.63 to about 24mm. 2023 Celestron, LLC. I focus using a moonlight electronic focuser and focusmax. By using this site, you agree to our Terms of Use. Your mileage may vary. ), but stars seemed a bit tighter and their colors were richer and more dramatic. CPWI has an extensive object database, employs PointXP mount modeling, and more. 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. Any comments gratefully received. Benefits limited to hardware and conditions? Maybe I got a lemon. Contiguous US Customers:All items we sell ship for free within the Contiguous US. 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. But nearly every observer who installs one of these devices is pleased with their performance. This is a. If the reducer is placed elsewhere, at a position called the operating distance, the focal reduction factor will not be as advertised. A former wireless communications consulting engineer and management consultant to various Fortune 500 companies, Manish started Agena AstroProducts in 2003. 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 . October 11, 2010 in Discussions - Scopes / Whole setups. Reproduction without permission prohibited. and you will be fine. 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. Fumbling around in the dark, fine threads might be a problem. However, this also came at a cost, as the sky background in the Antares was slightly brighter. 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. They both are great and I doubt my eyes could detect a difference in any one of them including the Japan version. An eyepiece with a 27mm field stop yields a true field of 1.03 in the C6 at f/10. . But in the Japan version I have never noticed any anomaly like the ghosting in the China R/C. I use the same back spacing for both on a small 6" Celestron SCT. I am a purely visual observer, so will evaluate for visual use only. I only have the Celestron f/6.3. Sky recognition technology that has revolutionized the manual telescope by eliminating the confusion common among beginners and enhancing the user experience for even seasoned telescope users. All rights reserved. All rights reserved. Description. Opticstar F6.3 Focal Reducer / Corrector. No difference. Read our guide! But while the image gets brighter, the size of the image circle gets proportionately smaller. 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. 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. 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. 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. 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. 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. As a consequence, the standard f/6.3 and f/3.3 focal reducers for SCT scopes do not work. If used before or beyond the working distance, unwanted image distortion may result. The review is a subjective visual impression, which is interesting but not best evidence. They provide 0.75x focal reducers for these telescopes that takes an f/8 instrument down to f/6. The Reduction Factor and the Amount of Reduction are inversely related. 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. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer.
West Sacramento Section 8 Housing List, Is Ryan Bingham Related To Ken Curtis, Articles A
West Sacramento Section 8 Housing List, Is Ryan Bingham Related To Ken Curtis, Articles A