Reducer Lens .7x - EdgeHD 800 How about for visual observers? I use the Celestron version and it seems OK for both visual and imaging. The internal surfaces are blackened and glare-threaded to provide the highest contrast. Contiguous US Customers:All items we sell ship for free within the Contiguous US. JavaScript seems to be disabled in your browser. But I am rusty, can you condense a bit for me please? In most cases, the easiest option is to choose the focal reducer made specifically for your telescope. It is not a corrector or flattener. CPWI has an extensive object database, employs PointXP mount modeling, and more. 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. 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! 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. 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. Place the plastic covers on the lens when not in use to reduce the dust collection. 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. I would not use the reducer with a 2" diagonal or eyepiece in the C6. I've seen some older threads saying that the Celestron, Meade and Antares FRs are all the same and manufactured in the same factory. Many focal reducers are meant to be used within a few millimeters of the specified working distance to achieve the best possible image results. Clearly cost is a big factor for satisfied users. if the illuminated field is 27mm wide without the reducer, it will be 27 x 0.63 = 17mm with it in place. Product Details. I have had the Japan unit on the back of my C5 since 1994 or thereabouts. Never used one, but read the reviews here that suggest a coating problem. And, the reality is that every F/6.3 RC out there Celestron, Hirsch, Astromania, etc., etc. 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) Share Customers Also Purchased Description The C8 has no noticeable vignetting with a 32mm Plssl in the f/6.3 reducer. 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. If I had to chose one, I would base my decision on your level of light pollution perhaps the Antares for its slightly higher transmission if you live under less light polluted skies, but the Celestron for its greater contrast if you are dealing with a suburban or urban light dome. I have both the Antares and the Celestron reducers. Focal reducers also move the effective focal plane of the objective inward, that is, towards the objective (see Figure 1). The Antares f/6.3 Focal Reducer for Schmidt-Cassegrain Telescopes is a low-price option for reducing the focal length of your Schmidt-Cassegrain telescope from f/10 to f/6.3. Oceanside Photo & Telescope wants our customers to shop with confidence knowing that you will always get the best deal available. Antares or Celestron? - thanks. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads I found both to be very good. I have a Raspberry HQ camera, a Sony TV Zoom 12.5-75mm f1.8 and a Astromania 1,25" 0.5x focal reducer. Right off the bat, I was struck by how similar the two R/Cs were. Article Agena AstroProducts, 2019. 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. The stars at the edge could be worse or better. There is one difference though the Antares came with only one lens cap whereas the Celestron had a cap for both ends. By 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. I've heard and read all kinds of things about the Antares being only a reducer and not a corrector, etc. 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. It also leads to larger (although fainter) images of extended objects like the Moon or planets for astrophotographers or visual observers. Celestrons patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if youve never used a telescope before. ), 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. 2. Reducer Lens .7x - EdgeHD 800 Learn More. 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. 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. 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. As per the OP I still can't see any reason to buy the Celestron for significantly more $$$. Perhaps not exactly- there will be some uncertainty because of manufacturing tolerances and so forth, but it will be close. 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. 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. Please re-enable javascript to access full functionality. . 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. Fumbling around in the dark, fine threads might be a problem. 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. 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. Edited by Tony Bonanno, 16 April 2021 - 06:44 PM. 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. Who cares? Meade once made an f/3.3 focal reducer for SCT scopes. The lens has a knurled surface, providing a tremendous gripping surface for threading/unthreading. Sharpness is essentially the same. Generally, views through the Antares seemed a little more transparent and brighter. Reducer Lens .7x - EdgeHD 1400 For example, many focal reducers designed for f/7 or f/8 ED refractors such as those from Tele Vue, William Optics, Sky-Watcher, and Meade are designed to have a working distance (or back focus) of 55mm. 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). Edited by bluewater, 05 September 2020 - 11:27 AM. Request stock alerts and we'll let you know when the item is back in stock. Another factor to consider: focal reducers also increase the angle at which light approaches the focal plane. It's highly unlikely that they could be so precisely identical unless they were. Sign up for a new account in our community. Depending on the design of the telescope, they may require separate focal reducers if they require focal reducers at all. This should not be the case if they have their purportedly different focal lengths. Here, there was a subtle difference . Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. riklaunim Members 559 3,445 Location: Poland Posted October 11, 2010 They are reported as identical. The review is a subjective visual impression, which is interesting but not best evidence. Most different was that the sky background was a little darker and more uniform, providing a tiny contrast boost for fainter objects. 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. Product Details 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. For the best experience on our site, be sure to turn on Javascript in your browser. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. 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. Hello! The Antares focal reducer comes in small box. Wow, that is a very detailed discussion! If the reducer is placed closer to the eyepiece or camera than the distance D, the reduction factor decreases. On the camera side, the focal reducer has male M42x0.75 or M48x0.75 threads that attach directly to the T-ring (with an M42-M48 adapter if necessary). I wont bother with differences in packaging, caps, etc. 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. It was also a little brighter in the center of the field with subtle darkening in the outer 20% or so.
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