SKU: CEL-94245. 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. Possibly the design of the Antares was changed .. Thanks Peter! 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. 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. We have corrected # (iii) after equations 6 & 7. 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. Hello! Stars had a tiny bit more sparkle and pop. Reducer Lens .7x - EdgeHD 925 Learn More. I have both the Antares and the Celestron reducers. No difference. It's important to match the back focus to within a millimeter or two to get an optimal image, especially with cameras with larger sensors. It's an either/or proposition: reducer and 1.25", or 2", but not 2" and reducer. But the smaller image circle means there is a limit to the field stop of an eyepiece that can achieve an unvignetted image. If I had to go out on a very thick limb, I would have to say that these two reducers/correctors are, indeed, identical the exact same glass in slightly different housings with different lettering. If used before or beyond the working distance, unwanted image distortion may result. I think I remember hearing the reduction factor is slightly different, cant remember more or less reduction. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. Celestron Focus Motor for SCT, EdgeHD & 8" RASA, Celestron C6 0.63 reducer/flattener back focus. Quite interestingly it bears the very same engravings of the Meade 4000 r/c (including "series 4000") except for "MEADE". Dedicated focal reducers for refractors are intended primarily for imaging, not visual observation. If the reducer is placed closer to the eyepiece or camera than the distance D, the reduction factor decreases. 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. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2" astronomy filters. Meade once made an f/3.3 focal reducer for SCT scopes. They are also less expensive than many external focusers of similar build quality. This "speeds up" the optical train by reducing the focal length and magnification of the scope, requiring less time to integrate the same signal. I focus using a moonlight electronic focuser and focusmax. Any comments gratefully received. Free shipping $189.95 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. 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. Both exhibited consistent reduction, identical field flattening, and edge correction properties, and both were high quality optically and mechanically. 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. The focus barely shifts between filters and I suspect any shifts I do get are down to the filters and changes in temp. Each focal reducer has a fixed specification called the working distance or required back focus. The nominal design reduction factor of these reducers is typically 0.5x. There is a way to make subjective data more useful and that way is proper blind, or better still. I found both to be very good. The Celestron f/6.3 is ~150 compared to the Antares at ~70. Description. It covers the basic optics and design specifications of a focal reducer, and goes through some practical factors to consider when selecting and using a focal reducer. They never really recovered from selling a few 15 years back with element reversed. The camera side of the focal reducer is threaded for a T-adapter with wide M48 threads, or in some cases, with smaller M42 threads. Clearly cost is a big factor for satisfied users. Many Ritchey-Chretien telescopes available today are made by GSO. 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. Turn it on and push Align. In about three minutes, youre ready to observe! As one increases, the other decreases. He also holds a Ph.D. in engineering physics from McMaster University. The threads were similar on the eyepiece end, but a bit smoother. This may be a problem if the focuser tube or the diagonal (for visual observing) is too narrow to accept light at this larger angle. I would not use the reducer with a 2" diagonal or eyepiece in the C6. Yet, the Antares still easily and fully threaded without any hitches. . 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. 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. Thanks for any advice or experience you could share. External Focusers for Schmidt-Cassegrain Telescopes 3.1 The Basics of SCT Threads 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. Also read the reviews here, including those at 4 stars. October 11, 2010 in Discussions - Scopes / Whole setups. This focal reducer is made to attach to the rear cell of Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. We have placed cookies on your device to help make this website better. For the best experience on our site, be sure to turn on Javascript in your browser. 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. There are also third-party vendors such as Hotech. 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. The previous post shows the reducer on what appear to be two different refractors. I happily cycle through LRGB filters to build the image rather than do a whole run of one filter at a time. 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. This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. How to Set the Correct Back Focus for Your Telescope (Guide) If you do so, you will achieve the design reduction factor. A little longer light path with a 2 Baader click-lock, low profile 1.25 adapter, and the 1.25 diagonal; The Celestron f/6.3 is ~150 compared to the Antares at ~70. . Rather than a direct side-by-side, I swapped the reducers so that I was using them on the exact same, well-collimated instrument. Steve 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. Our proprietary StarBright XLT optical coatings dramatically increase transmission, up to 97.4% on our Schmidt corrector lenses. If you are using a camera that has a back focus of less than 55mm, additional spacer rings will be required between the reducer and the camera. 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. For this shoot-out, I used a standard Celestron C8 with Starbright coatings. Product Details. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.International Customers:Free shipping does not apply to international orders. When the camera sensor is placed at this distance, the reduction factor of these reducers is 0.75x. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. The lens is housed in machined aluminum for are machined aluminum black anodized. Celestrons FREE planetarium app is an astronomy suite that redefines how you experience the night sky. F 6.3 focal reducer/corrector. - Discussions - Stargazers Lounge Refractors, or SCTs with external focusers, may not have sufficient in-travel to reach focus in some configurations. This award-winning optical system reduces visual defects like field curvature and coma, creating an ultra-flat field for pinpoint stars all the way to the edge of todays largest imaging sensors. Reducer Lens .7x - EdgeHD 925 So Celestron buyers like Celestron, Meade buyers like the Meade and Antares buyer like the Antares. How about for visual observers? This fully multi-coated lens provides maximum light transmission with near full-field illumination. InternetSales@optcorp.com. I have a made in Japan 6.3 R/C and a made in China 6.3 R/C. However, because the field curvatures in refractors and SCTs vary a lot, I would predict unpredictable effects inre: field curvature. By What is likely is that fatigue sets in, and also that as the targets move toward or a way from the meridian there will be changes for that reason alone. I'd favor the Japanese Celestron version over the others that are commercially available. Since 2008, Brian has taught astronomy to tens of thousands of stargazers through his websites OneMinuteAstronomer.com and CosmicPursuits.com. 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 . In both cases will end with a similar tfov. ), 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. Photographically you also get a wider field and much shorter exposures. Thanks guys, appreciate the feedback. 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. Does anyone know if the Antares 4000 focal reducer is as good as the Celestron focal reducer. The most popular accessories for your new telescope! He tested this on an 8 Celestron , I have a Celestron 6SE. 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. Can you tell me about the use of reducers in Maksutov-Cassegrain telescopes? Orders placed over the weekend will be shipped on the following Monday. Celestron Solar Safe filter technology is GUARANTEED SAFE for direct solar observation and has been independently tested by SAI Global Assurance Services.

Log Cabins For Sale In Placerville, Ca, Seneca County Ny Sheriff's Department, King Kullen Human Resources, Articles A