Celestron focal reducer back focus In this set up the focal reducer is attached to the scope, then the SCT/T2 adapter (a long not a short one), then the 11mm and the 21mm extenders that came with the camera, then the May 21, 2017 · According to Ken's ray traces, the C925 starts to loose aperture at about 90mm with the standard focal reducer, and about 150mm without the reduce, but the falloff is quite gradual to 200mm so that only . 3 Reducer + ASI Camera ? - posted in Celestron Computerized Telescopes: I just borrowed an 8SE and want to use my Celestron 6. 7x Focal Reducer for 8″ EdgeHD features a custom 4 element optical design engineered to maintain the flat-field performance of our award winning EdgeHD optical system. 25 Focal Reducer Add back focus: Female SCT to T2 male adapter = 8. 3 focal reducer/corrector requires a backfocus distance of 105mm from the end of the reducer to the imaging sensor on your camera. 63x focal reducer/corrector. So last weekend I decided to see if I could find the cause. Attach your T-adapter (#93646, sold separately) onto the rear threads of the focal reducer. Apr 25, 2020 · Did calculations for back focus with/without Reducer - OAG and cameras have enough adapters; Always intended to get the Celestron 0. But when I attached the Celestron OAG and my Canon 1300D Feb 19, 2021 · If you are using a DSLR camera with this Antares reducer, there’s an easy way to get right at the 105 mm back focus. Since the celestron f6. Aug 24, 2021 · See link below optimum backfocus for C8 is 5 inches, or 127 mm with no focal reducer. Regards, Mar 30, 2022 · Page 1 of 2 - Optical Train for 8SE + 6. 55mm Meade DSI IV = 17. 63 reducer, a Canon rebel, and required adapters. Aug 4, 2018 · Back focus 8" sct - posted in Cats & Casses: Hi guys, Im sure Im traveling down a well trodden road with this question, but here goes. Afterwards I put the Mar 12, 2023 · I have been using the Nexstar Evolution 8 SCT with 2 Celestron Dielectric Star Diagonal and 2 eyepieces for Visual. Celestron's new EdgeHD reducers features a custom 4 element optical design engineered to maintain the flat-field performance of our award winning EdgeHD optical system. I have a Celestron 8SE on a SkyWatcher EQ6-R Pro mount. its not the Edge HD just the standard tube. Does anyone know or have a diagram of how the focal reducer and whatever spacers/etc. Heres the equipment I want to use for DSO imaging: Celestron f/6. 3 reduction. celestroducer-corrector Feb 18, 2022 · Back Focus Messed up with Celestron Focal Reducer installed - posted in Celestron Computerized Telescopes: Hi guys, Last night I installed the Celestron Focal Reducer on my Evolution 9. 05 back focus for my 9. My first May 30, 2020 · Back focus for SCT - posted in Cats & Casses: I’m waiting for an asi camera to start imaging, I’ll be using a 6. Does anyone know how to measure back focus with this equipment and what the correct distance should be? May 18, 2021 · Where do I measure back focus on an SCT w/focuser? - posted in Equipment (No astrophotography): Hello all, I have been reading many articles and watching many YouTube videos on back focal distance. I believe the correct back focus for this unit is 105mm of back-focus: Provides generous back-focus to accommodate additional accessories and a wide variety of cameras. Results are amazing both visually and photographically. I am just now learning how to set everything up. Feb 13, 2022 · To do this, you simply remove the reducer + SCT adapter and replace it with the shortened Celestron T-adapter attached to the thin female M42 adapter that came with the OAG. My main purpose is to get a bit wider field of view, I know with this scope model and focal length The Celestron 6. I have a new celestron f6. 👍 Aug 20, 2022 · Backfocus With and Without Reducer - posted in Beginning Deep Sky Imaging: I had posted this in the telescope specific forum -- but now seems like more of a general AP question -- so thought Id check here. 63x FR. 3 focal reducer to C6/asi 533 - posted in Electronically Assisted Astronomy (No Post-Processing): I am waiting for the new night owl for use with my c6/asi 533 and plan to order a f/6. 3 focal reducer and ZWO ASI585MC camera to get started on EAA. The plate solving software will give you the focal length at that back focus. Celestron and Meade offer focal reducer/correctors for their f/10 Schmidt-Cassegrain telescopes that alter the effective focal ratio to f/6. The focal reducer threads directly onto the rear baffl e lock nut (see Figure 1) of your EdgeHD telescope. 3. 7 focual reducer and a new the celestron deluxe OAG. Camera Spacing Since optimal photographic back focus of 146 mm is the same with or without the focal reducer attached, the optional Jul 3, 2021 · Backfocus for a C6, no reducer and a ZWO - posted in Equipment (No astrophotography): Hello all, First time poster, here. So at native say your wiggle room is +/- 2mm, well with the FR it now becomes +/- 1mm, if you went to F/2 (not possible) your margin becomes 0. If your back focus with the reducer is 105mm, then the focal length should be about 1410mm. 75 thread). . After much deliberation, I have purchased a f6. 3 reducer in front of a 2" diagonal, and especially with the extra distance from the visual back doesn't allow most 2" and many 1. These are the parts that should get to the required 105mm back focus with the 6. Not terrible, but enough that I notice it. I have a celestron 8 sct (non HD) with a starizona 0. With the Celestron Reducer/Corrector Lens, that’s precisely what you get. 25 inch T ring and adapter GSO ND filter 50% transmission Celestron 40 mm plossl, 2x omni Barlow and x cell lx 5 mm ep I wanted to get a focal Aug 27, 2021 · Not at the same level of astro quality I know, but I'm struggling with a C8 (non-EdgeHD) with the Celestron 0. 63x focal reducer, and am having problems with extreme vignetting. This innovative focal reducer effectively decreases the telescope's focal length, transforming it to f/6. I do realise EdgeHD 8” – Optimum Back Focus Distance Attaching the Reducer 1. Celestron specifications and Astronomy Tool Field of View Calculator: 6SE w/ f6. 5mm to the sensor. Jan 30, 2023 · The back focus for the . Aug 23, 2010 · In many 2" barrel eyepieces, few will come to focus with the focal reducer in the 9. 750 back focus. My imaging train is currently EdgeHD 8 --> Celestron 0. 63 times, taking it from 2032 mm to 1280mm. I know I need 105mm back focus, but I am not sure where the extension is supposed to Apr 13, 2009 · Focal reducer wont reach focus. Assume an SCT with a full frame camera (Im using a Nikon Z6 and Celestron 8Edge): How, if at all, does back focus impact vignetting? Does the mirror travel (achieved with the focuser knob Feb 7, 2021 · Since I use the Celestron 0. Both the mount and the scope are performing very well. 7x focal reducer, Optec TCF-Leo, ZWO OAG, ZWO 1. If you have a reducer/flattener combination, the back focus is critical and usually about 55 mm. The 105 mm in the above equation is measured from the edge of the reducer to the image plane (e. from the edge of the focuser/reducer. 3 reducer and gives me less vignetting as well. From what I have read, the optimum backfocus for the Celestron f/6. 63 reducer/corrector - posted in Beginning Deep Sky Imaging: I routinely use an Atik Horizon on Hyperstar with a 8 Evolution. 2 focal reducer on my Celestron 9. The camera is supposed to have a 55mm backfocus. 475 in from 3 in-2 in Reducer Plate 5. This factor is designated by a power that is less than 1, and it usually lies between 0. 25 SCT. 25 tube and have noticed the scope doesn't have near the back focus that a C11 does. Feb 26, 2021 · Page 1 of 2 - What's wrong: EdgeHD 925 with . Focal Length The exact focal length of the reducer/telescope combo depends slightly on where in the optical path the SCT Corrector lens is placed. I don't know why you are getting what you are getting, but yes, something is not right. 3 reducers are very poor in comparison to the Starizona SCT FRs. Jan 21, 2010 · I've got a C9. 3 reducer / corrector ZWO M68 OAG-L, to support using an off Nov 4, 2012 · Back focus distance from primary mirror baffle tube lock ring (in) C5: 5 in: C6: 5 in: C8: 5 in: C925: 5. 3 focal reducer and my ASI1600MC camera. Telescope: Meade LX90 10 FL 2,500, f/10 Camera: Nikon D500 I had a Peterson Engineering EyeOpener installed a few years back but when the FR did not screw into it (might need an adapter, I think) I put back Aug 16, 2018 · Celestron OAG backfocus calculations - posted in Equipment (No astrophotography): Hi All, Ive read a number of topics here about working out the backfocus for various OAGs including the Celestron (which I have). I recently decided that I would like to increase the F!0 field and view and I purchased a Celestron 6. Jun 2, 2022 · I do not know by actual test that 105mm is the optimum spacing for the current f/6. 3 reducer and the recommended 105mm doesn't give you the spec'd focal length of 1280mm , 105mm gave me a focal length of 1320mm I can't remember what back focus distance I'm using but my focal length is now very close to 128 Apr 18, 2021 · With the Celestron OAG and FR I am at 104. Without the Focal Reducer, the chain looks like Visual Back Mar 8, 2014 · An overview of the Celestron f/6. 3 focal reducer/corrector requires a back-focus distance of 105mm from the end of the reducer to the imaging sensor on your camera. 3X focal reducer requires a back spacing, that is the spacing from the back of the focal reducer to the sensor in the camera, of 105mm. Apr 18, 2021 · Page 1 of 3 - C8 with f/6. With the reducer you start losing aperture at just over 100mm of backfocus (behind the reducer) and by 130mm of back focus aperture has been cut down to 140mm. I do not know if the Televue components will give that spacing or not. I have ordered the following Accesories to go with it, Solar filter Cls filter 1. . my imaging camera is the ZWO asi294 mc pro. I decided on the following major components in the optical chain: Celestron C8 SCT (which I inherited from a previous user) SCT f/6. 3 focal reducer has a recommended back focus distance of 105mm from the rear cell of the reducer to the camera's image sensor. Also, when I use Nina, when I go to plate solve it tells me my picture is 1666mm. Using CCD Calc to compare my actual field of view with its Jul 22, 2021 · 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. Mar 22, 2018 · “The Celestron focal reducer does give a small range of image amplification/focal reductions at different reducer-to-sensor distances, however the sensor position for optimal image quality for your set up depends on your specific telescope/reducer/camera sensor combination. Nov 11, 2023 · The Ultimate Back Focus Guide to Reach Zenith with a Focal Reducer on a SE, Evolution or CPC Mount - posted in Celestron Computerized Telescopes: I will ask your indulgence to my using the word Ultimate in the title, but my aim was to put together in one place everything necessary to achieve the correct back focus spacing with a Celestron 6. Jan 30, 2024 · Celestron's 6. 7x Focal Reducer—a warp-speed upgrade for your 8" EdgeHD telescope that launches your astrophotography to exhilarating new realms! This powerhouse of precision engineering brings the universe closer, more comprehensive, and brighter, ensuring your cosmic shots are spectacular. May 4, 2017 · My combination focal reducer and field corrector lens is f/6. With the Oct 7, 2022 · Need help with back focus with Celestron Edge HD8/0. 7x Focal reducer - posted in DSLR, Mirrorless & General-Purpose Digital Camera DSO Imaging: I am trying to add a ZWO ASI 2600 MC Pro and OAG to my imaging train. Although the Reducer/Corrector Lens diminishes the Mar 22, 2018 · Page 2 of 2 - Calculating back focus for Celestron 0. 25, C11 and C14 EdgeHD Telescopes. 3 reducer is operating at f/5-f/5. https://www. A reduction in focal length that magnifies your field of view by a cosmic 0. Also allows use of existing EdgeHD T-Adapters and other Celestron imaging accessories Apr 4, 2022 · Here is a solution for achieving 105-mm back focus for a Celestron C8 SCT - posted in Beginning Deep Sky Imaging: Hello, all, Im still taking baby steps in the world of AP, currently assembling my kit. How do people normally build the optical train for this to avoid hitting the base of the SE at high altitude? I know the reducer screws directly onto the back of the tube replacing the Apr 18, 2021 · With my C11, I find that 85mm of back focus works great with the Celestron 6. Im trying to connect a ZWO 178mc to a Celestron C6 without a reducer. 7x focal reducer turns your 11" f/10 EdgeHD telescope into a full f-stop faster f/7 scope, increasing your photographic field of view by 43% and cutting your deep space exposure times in half . 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. Performance The diagram above shows how the SCT Corrector improves the off-axis spot size on a Celestron 11" SCT. After spending a bunch on the camera and focal reducer (and a new laptop), now Im discovering that I may Mar 4, 2020 · Focal reducers for 9. 25 sct which states is a back focus of 105mm. 8mm over the required 133mm to achieve parfocal with the SCT - according to the OAG manual. 3 focal reducer screws directly to the visual-back thread of all popular SCTs and converts f10 instruments to f6. 3 focal reducer/corrector was intended for both visual and photographic use. 3 - posted in Beginning Deep Sky Imaging: Hello, I have been struggling to get the correct backfocus for the Meade FR f/6. 3 SCT focal reducer/corrector. Seems like there Apr 12, 2021 · The f/6. I have just bought a Celestron Nexstar 8SE and ZWO ASI224mc camera and was trying to use it to view Jupiter with SharpCap. Nominally May 28, 2017 · Celestron Reducer/Corrector -f/6. 3 reducer has a Jan 5, 2022 · I found 105mm to be correct for the Celestron and Antares F/6. Jun 8, 2018 · The Celestron Evolution 8" has a single fork mount, with inadequate back end clearance (as it turns out) for the ASI1600MC cooled with the 0. 2 but I assume this is close enough to the design focal ratio that it isnt causing This, added to the inability to utilize longer focal ratios for certain objects, led Celestron to design the four-element, fully multicoated f/6. 3X focal reducer/field flattener is a very popular accessory for non-Edge SCTs because it reduces the focal ratio of the SCT from its native f/10 to f/6. 3 reducer costs over double that of the Celestron (triple that of the Meade) but I get a much flatter field across more the the image area than with the Celestron (only about 50% in the center for the Celestron, easily 70% for the Starizona) May 9, 2022 · A focal reducer such as the one for C11 with 0. Nov 8, 2020 · Backfocus Focal reducer f/6. Edited by Eddgie, 29 October 2022 - 09:14 PM. ), you will see significant vignetting in the corners. The Manual and user groups agree that back focus measures start from the flat end of the treaded free end of the focal re Jun 7, 2017 · Question about back focus on a C8 - posted in Cats & Casses: I think I know the answer but does a C8 have enough back focus in the following chain? C8, Celestron focal reducer/flatener, Baader 2 clicklock, Baader 2 clicklock diagonal, 1. 55mm 😁 Here is my set up from rear of C9. 3 reducer spacing for SCT - posted in DSLR, Mirrorless & General-Purpose Digital Camera DSO Imaging: Hi everyone, I finally got a focal reducer for my LX90 just in time for galaxy season! I took it out tonight to give it a try for the first time and I seem to be getting WAY more reduction that Im supposed to. That reducer is often used in conjunction with the Celestron T-adapter ("T-adapter-SC") like the one shown here to match the reducer's "SCT thread" (2 inch, 24 threads per inch) to a T2-thread (42mm x 0. There's no/little/confusing information about what back focus is required, and from which point on the reducer is it measured. I have been struggling to get some exact info on back focus for this setup. 8x. 5mm, so you would need to 114. First is a Meade Series 4000 f/6. I am using a Celestron HD8, 0. 3/ The optimum back focus distance is 105 mm for a 6. The Celestron 93633-A adapter has nearly the correct length for being parfocal when you Oct 6, 2020 · Help me to understand back focus with a SCT - posted in Beginning Deep Sky Imaging: Ok, so I cant seem to find consistent answers and hoping these fall under the old saying of there are no dumb questions. I now have the following in my optical train: Celestron Focal Reducer Canon EOS M42 EF-Mount T-Ring T-Adapter for 9. Can someone please educate me? I am trying to set Feb 15, 2018 · The Celestron F/6. Aug 14, 2022 · I've been looking closely at back focus with a Nikon DSLR with T Ring adapter, total back focus 55mm with the 6. Also allows use of existing T-Adapters for EdgeHD 800 and other Celestron imaging accessories; One full F-Stop faster than f/10: Reduces the exposure time by one-half to capture the same brightness of object Maintains the same back-focus as when used at f/10: Unlike generic reducers the EdgeHD . 63 Focal Reducers with SCTs - posted in Beginning Deep Sky Imaging: I have a Celestron C6 SCT, which is the original C6. Sep 25, 2017 · EdgeHD 8" & f/7 reducer back focus distance - posted in Cats & Casses: I have an EdgeHD 8 with f/7 reducer and Celestron OAG. Celestron says the scope backfocus is 5, and if I hold the camera back from the scope at about 5, it does focus. Jun 20, 2021 · REDUCES FOCAL LENGTH AND F/RATIO BY 37%: Simply thread the reducer onto your telescopes rear cell and an f/10 Schmidt-Cassegrain becomes f/6. The reducer makes the image about four times brighter compared to f/10, which is great for capturing faint deep-sky objects that cover a wide field of view, such as nebulae. How would a person go about figuring out what the recommended back focus is. are needed to connect to a C6 and asi533? Does the The Celestron f/6. At 105 mm back focus, I got 1000 mm focal length, which is x0. 25 SCT The Canon EOS 7D requires 105mm from the reducer to the 7D sensor. This is a classical issue. Im trying to get it to work with a ZWO ASI533MC. I have outline 4 solutions below with the parts needed in each case. Explicitly designed for Celestron Schmidt-Cassegrain telescopes, this unique lens reduces your telescope’s focal length and f/ ratio by 37%, turning your long focal length telescope into a fast, short focal length instrument. F6. 63x reducer, which has a recommended back focus recommendation of 105 mm, does the introduction of the UHC filter change the back focus distance? 2. The example camera in this video is a Canon SL1, but this will apply to all DSLR cameras as long as you get your focal distance to 105mm. The specifics of male thread at the end of the focal reducer is unclear to me, but I believe its a general SCT-thread - as is at the naked base of the Ne Apr 26, 2021 · In this episode of Back-Focus 101 I cover the basics for attaching a DSLR camera or CCD/CMOS style camera to either the Celestron C9. 2. 2mm, if you The Celestron f/6. 25", 11", and 14" maintain the full 146mm back focus, making it easy to switch the reducer in and out of image trains as desired All EdgeHD scopes cover a full-frame DSLR at native focal ratio, and all but the 8" will cover the same field with the 0. I ran a platesolve with APT, which then Apr 29, 2022 · The back focus is from the flange of the reducer, which is the very end of this reducer. Anyway, i want to use a Focal Reducer, and a . 3 reducer between the SCT and the visual back, and then put your diagonal and eyepiece back on, you don't have to twiddle much with the focus button to reach focus again. 3 Focal Reducer/Corrector lens. This surprised me as I was of the Focus your telescope as usual (i. I have a Celestron 6SE with standard Alt/Az mount, Zwo 385MC camera, and Celestron 0. The back focus with the reducer on your 8 Edge HD will be 133. Is the correct backfocus for the ASI585MC Camera using the Celestron C8 scope 55mm. 25 when used with the Celestron OAG Feb 9, 2018 · In my experience, the f/6. 3 reducers. I couldn't bring it into focus. 63x focal reducer which can be threaded onto the back of the SCT. An f/11 instrument becomes f/7. I tried swinging the focus knob all over the place to no Unveil the Celestron . 3 focal reducer. and you will be fine. So, the original focal length of the telescope is F = 0. 3 reducer. 3. 05 mm. The Antares f6. 4mm OAG female T2 = 4. 3 Reducer (https://www. 25" eyepieces to come to focus. 55mm close enough. When working with focal reducers, is the focal length specification a constant? For example, the Celestron FR is listed at 283mm focal length, and at the ideal sensor distance of 105mm you get a . 63 reducers - Celestron vs. Remove the visual back from the rear of the telescope. Attached Thumbnails MarMax and Craigar like this Jan 22, 2021 · The optimum back focus distance for the Celestron 9. I received a Meade 4000 . These two scenarios contradict each other (I think they do anyway) & confuse me (that's for sure!). Feb 13, 2010 · Putting an F6. My understanding is the Reducer has a 105mm back focus Apr 4, 2012 · The 0. Apr 4, 2018 · Celestron Focal Reducer Back Focus - posted in Meade Computerized Telescopes: Hello all, I am having some trouble focusing with a Celestron f/6. 25" diagonal, it will operate at f/6. Im using a NexStar 6SE SCT. the backfocus distance from the focal May 8, 2023 · "The Celestron f/6. Am I doing something wrong? I install the reducer to the back of the telescope followed by the visual back and then diagonal. 25 Helical focuser. 5mm Total is 104. I understand both the guide and main imaging cameras need to be parfocal, however the OAG manual doesnt state what the distance from the centre of the prism to the top of the guide Mar 24, 2022 · Effect of filters on back focus? - posted in Beginning Deep Sky Imaging: I have noticed, to my surprise, that my UHC filter changes the focusing of the scope. I don't have this problem without the focal reducer. Dec 20, 2024 · Using a Focal Reducer. When using the Celestron 0. This configuration also means that your guide camera remains in focus with your imaging camera when you switch back and forth. Im at f/3. 3 focal reducer, Celestron OAG and guide camera (Touptek) as well as main camera (Player One). 63 reducer. The reducer shortens the 8HD's photographic back focus from 133mm to 105mm (measured from the reducer to the image plane). 3 reducer (not the 0. I managed to find a visual back that will give me the approximate correct spacing from the reducer to the CCD chip. 7x Reducer but find it hard to get (out of stock in UK); With the reducer there is lots of clearance in front of the OAG (I ignored this), but less without one. The example camera in this video is a ZWO Nov 14, 2023 · Focal reducers are an essential tool for EAA used to speed up the optics and get wider fields of view but reaching zenith with one on some Alt-Az mounts can be a challenge. celestro-celestron-scts . The sharpest possible focus for a given eyepiece is about 3 to 4 counterclockwise turns of the focus knob from the best focus point without the Reducer/Corrector lens installed. Here are the Celestron recommended distances for various EHD models behind the surface of the telescope’s rear cell 2″ (for C8) and 3″ (for C9. Does it reduce the Telescope Aperture like a normal reducer does? Seeing that it keeps the nominal back focus the same, wouldnt It also keep the full Aperture? By Apr 21, 2023 · Page 1 of 2 - NexStar 8 focus problem with focal reducer - posted in Cats & Casses: A couple of years ago I upgraded my NexStar 8 by replacing the NexStar mount with the Celestron AVX mount. I like this setup a lot and would like to explore EAA. It should be 1500mm or close to that Jun 9, 2022 · I have searched the web and user groups for answers to obtain the correct 146. I had a couple of questions around the procedure. This combination works well for prime focus imaging of terrestrial or celestial targets. If it's not correct add/remove back focus until you get the correct focal length for that scope/reducer combo. 63 magnification. This total distance includes the focal reducer, OAG components, Canon T3i and SLR T-ring Dec 22, 2010 · Page 1 of 2 - reducers, back focus, and spherical aberration - posted in Cats & Casses: Ive been cutting my teeth with DSO imaging using a Celestron 6 SCT with an f/3. I have 2 questions Mar 17, 2021 · Connecting f/6. I have recently acquired a few bits of kit that will be used with my 85 C8, and I want to make sure that I am following the correct procedure with them. Should I get one of each? Im tempted to just buy Celestron but is the extra cost Jun 17, 2003 · Thus, if the focal length of the f/10 system is F, then the focal length after using the reducer corrector would be 0. Combined with the Celestron OAG the total distance is about 24. 25, C11, C14) threaded baffle tube lock nut: Mar 8, 2019 · This works if you are only using a focal reducer. Assuming you use the reducer with the stock 1. 975 in from 3 in Primary Mirror Baffle Tube Lock Ring Jun 13, 2019 · 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. In use, I initially set the extension to about mid-travel (about step #2000), focus with the SCT focusing knob until I am close, lock down the Jun 26, 2023 · F/. Apr 28, 2020 · The Celestron f/6. Everything was going well until Apr 1, 2010 · Page 1 of 2 - f/6. 25 reducer, ES 8. The Celestron SCT prime focus adapter coupled with a Nikon AI t-ring will provide the proper working distance. Aug 21, 2020 · For example, with the C5 starting with 1270mm of focal length, a 33mm increase in flange to focal plane separation will raise focal length by about 8%, but a add 33mm to the back focus of a C11 would only raise the focal length by about 3%. Is their a sticky explaining how you get the recommended back focus? How would you calculate in a focal reducer Aug 3, 2021 · I took the these back in 2006 or 2007 with the original Orion starshoot Deep Sky Color Imager with 8" LX200 and 3. HOWEVER, being F/7 the margin of deviation is less. I demonstrate how to attach the Celest Feb 16, 2022 · I'm slowly solving some issues with mine. Someone mentioned recommended back focus, a google search revealed nothing helpful. Because it is built into a 2in barrel the camera/FR combo can be inserted into the Crayford's 2in barrel so you retain the benefits o I have a Celestron C6 SCT with a 0. 975 in from 3 in Primary Mirror Baffle Tube Lock Ring: C14: 5. Yes, my little comets/stars shoot out like yours. 3). I dont think the C6 ever came out in HD. 25 SCT without a focal reducer is 5. 3 focal reducer using a Nikon or Canon that have 55mm with a T ring adapter and their sensor location. 3 to offer larger in screen DSO object sizes for smaller targets, hence rear OTA mounting with Celestron Focal Reducer. Assuming my Barlow is essential for capturing Saturn and that my focal reducer should not be used for Saturn but rather DSO type imaging instead Very much appreciate any advice, as I’m really looking for a good Saturn image tonight Jan 9, 2021 · Page 1 of 2 - back focus for a Celestron C9. 5mm) I ran out of turns on the focuser knob and the stars would not come into focus. If you have an EdgeHD, if one has a focal reducer, one only measures from the back of the focal reducer. 3 focal reducer, I know it reduces the focal length of the scope by 0. 25 and 11 inch Celestron SCTs, due to the physical length of the visual back and star diagonal. I'm planning to use it with the ASI1600 camera, but it seems that I can't figure out the proper spacing distance between the reducer and the sensor. Astromania - posted in Equipment (No astrophotography): I thought for sure this thread must already exist but I couldnt find it. Produces a corrected field of 24mm diameter. 25 and when ever I install this piece of equipment i can not get it to focus at all. Jan 16, 2015 · Page 1 of 2 - 8" EdgeHD back focus question - posted in Cats & Casses: On my 8 EdgeHD, what is the back focus distance using a Tele Vue standard long SCT Adapter (Visual Back) for 2 Diagonals, and the Televue 2 diagonal? I know that the aberration correction in this scope is designed for best performance at 5. Performance is similar on other size telescopes. These reducers thread on the back threads of the telescope tube and take the place of the visual back. 63F / 0. , for a DLSR 55mm to T-ring plus spacers to reducer). celestro-celestron-scts c172jeff likes this Jun 26, 2022 · Focal reducer for Celestron Nexstar 8se - posted in Celestron Computerized Telescopes: Hi guys, I just ordered a nexstar 8se which will be delivered around end of July. According to ZWO the "back focus" (actually the focal plane distance from the face of the camera) for the 120 MC is 12. It has the SCT threads & is exactly the right size. The tube ZWO supplies leaves a wide gap, though, so I need something more. That or there's another problem with the scope that I can't figure out Oct 29, 2022 · If your back focus is 139mm, this should yeild a focal length of about 2420mm. 63 ≈ 1 focal length unit (FL), given that 1 FL is the focal length of the system after reduction. 3 focal reducer on back end of scope. 7x provides generous back-focus to accommodate additional accessories and a wide variety of cameras. 4 inches, resulting in an f-number of f/6. I have attached a picture of my train. I'm not sure what I'm doing wrong. - posted in Celestron Computerized Telescopes: While reading another set of posts last week, I heard a lot of talk about using focal reducers to flatten the field, wider FOV. 7x uses the exact same 146. So if my camera sensor The Celestron 0. 63 x) on the Nexstar 8" SCT. 3 focal reducer on the scope. It can also be used with a Celestron 0. NINA/ASTAP calculated my focal length from the plate solved images as: 6SE w/ f6. Dec 26, 2024 · Backfocus for Nexstar 8SE with focal reducer and OAG - posted in Celestron Computerized Telescopes: Hi everyone, quick question (and possibly easy to answer for the ones who know it)I have a Nexstar 8SE with. Im wondering about back focus with the Edge HD 9. 3 FR on my Meade scope using a DSLR camera. I recently decided to give EAA a go. Jun 11, 2018 · Here you can find the document from the box and a CN review document: https://spideroak. 7x focal reducer and tried to focus visually, unsuccessfully, on the sun. Jun 11, 2018 · This combination focal reducer and field corrector converts the optical systems of f/10 Schmidt-Cassegrain telescopes to f/6. The back focus is 105mm, from the reducer's back element to the camera's sensor Jul 14, 2019 · What I have learned is to simplify things - backfocus is only 1 design characteristic and only matters from the last optical lens. COMPATIBLE WITH ALL YOUR ACCESSORIES: Once the reducer is installed, you can add accessories like a T-Adapter, visual back, star diagonal or off-axis guider as usual. Some people say that the backfocus is 85mm, others rather state 105mm. 3 Reducer/Corrector. 5mm spacing to get the best focus. 5mm OAG body = 29mm Male T2 OAG adapter = 12. Apr 10, 2021 · Correct procedure for setting focus and back focus with an SCT reducer - posted in Equipment (No astrophotography): Hello all. 3 reducer also has a 105mm back focus, the simplest thing is just to use the celestron #93633-A SCT t-adapter. 7X Focal Reducer compromises? - posted in Cats & Casses: Read a lot about this and how it does indeed work for visual use (pros), but Im looking for any cons that may be associated with its usage before committing. I don't have a focal reducer on it yet, but do have a FT crayford installed, so I'll be interested in seeing if you've got enough back focus to include the reducer. Without a focal reducer, the backfocus standard is from the nut on the rear light port. Now the Focal Reducer i purchased was a Meade. Yes, the 0. If I use the Celestron f/6. 25 edge HD with the 0. 63F (f/6. Simply, is the $87 astronania field reducer as good as the $125 Celestron one? Using on a CPC 1100 XLT I plan to buy two so I can stack them when I want. 3 reducer, OAG AND DSLR - posted in Beginning Deep Sky Imaging: I know there are many threads dealing with each of these components but I couldnt find one for my combination. 5mm ZWO filter drawer 2 inch = 21mm OAG medium T2 spacer = 11. 7 Focal Reducer - posted in Experienced Deep Sky Imaging: Having installed a new . Fits both Celestron and Meade SCT telescopes. Works great (for EAA) at f/2, but I wanted to try short exposure stacking at f/6. 7X reducers on the Edge HD telescopes does not change from the telescope's native back focus without the reducer. 63X focal reducer decreases the focal length of this same telescope to 50. Focal reducers also reduce back focus and, when used for prime-focus photography with May 15, 2018 · This topic is very timely because I have been trying to optimize the back focus of my EdgeHD 8 imaging set-up. I use the Celestron OAG for guiding and get round stars to the image edge with my canon 60D. 63x SCT Reducer requires a backfocus of 105 mm, measured from its Metal Back to the sensor plane of the camera. 3 focal reducer combined with a Celestron OAG. I think Im clear on the setup to achieve 105mm of backfocus when using the f/6. Also allows use of existing EdgeHD T-Adapters and other Celestron imaging accessories Apr 8, 2023 · Back focus for Celestron 6se - posted in Beginning Deep Sky Imaging: Does this look correct for back focus on a celestron 6se without a reducer? I believe it should be 127mm. When I checked the back focus to my camera chip it was about 118 mm or about 28 mm short of the specified back focus distance. That also has an effect on illumination. 67 reducer as a gift a couple years ago and never used it (I believe I could not reach focus). 63 reducer/flattener for my C6. So, I tried with a different backfocus distances between the reducer and the ASI294mcpro. 475" (139mm) from the primary mirror baffle tube lock ring. 3X focal reducer and still be able to point to zenith Celestron says 8se back focus is 5 inches (127mm) but just not sure what is part of that measurement. Offers a wide field of view with Schmidt-Cassegrain telescopes and reduces exposure time by a factor of 3. You can try an SCT threaded 2" diagonal which will attach directly to the focal reducer and reduce the overall length behind the focal reducer. 25 - posted in Cats & Casses: Hi, I have a Celestron C9. On the ZWO site they are showing a 55 mm back Mar 26, 2018 · Astro-Physics mentions subtracting the depth of the threads when calculating back focus when using some of their parts/adapters. Jun 10, 2020 · Question on . 63x reducer changes a few things on the C6, and there are even more changes as things get to some further back distance behind the reducer. 7x reducer as well Jul 3, 2020 · The same thing occurred when I had the Celestron f/6. 05 +/- 2mm (mine was 145. I have read that achieving the correct back focus is important when using this focal reducer. Visual Back plus sensor distance). I have seen some pictures of ZWO cameras on a C8 but they are all of the place with some that look very long, maybe Apr 23, 2020 · What is confusing me is that various pals in CN have told me they simply affix a regular (40mm long) Celestron visual back to the Celestron focal reducer and (fully) plug the camera's 1. 3 Focal Reducer Corrector is an essential accessory explicitly designed for SCT (Schmidt-Cassegrain Telescope) setups. 3 is nearly parfocal--in other words, if I insert the f/6. A EHD scope achieves its full capability when the focal plane is placed at a nominal back focus distance (NBF) from the scope visual back. 7x factor Jul 20, 2021 · 6. That said the 105mm figure is widely used and it matches the Celestron T adapter + DSLR back focus. 3 Reducer Corrector accessory makes it possible to have a dual focal ratio for the C5, C6, C8, C9 1/4, C11 and C14 telescopes (product 1), without sacrificing image quality. Jul 29, 2020 · However, I don't believe the actual back focus distance needs to be exact since SCT telescopes are quite forgiving in reaching focus with their movable mirrors. coelestron f_6. On the other hand, a 0. This is a fantastic product and probably some of the best money spent on a Schmidt Cassegrai Sep 15, 2023 · Still chasing stretched stars with my Celestron 0. 3 reducer backfocus help with zwo 533 - posted in Cats & Casses: Ive have Celestron SCT 8 with the Celestron f/6. I was setting up for some astrophotography but decided to enjoy Jupiter for a while first Mar 29, 2021 · The problem I was having was that even when I set my backfocus distance to 146. I was able to use my 1. Featuring multi-coated optics, it ensures excellent light transmission and reduces aberrations, resulting in sharper and brighter images across a wider Apr 11, 2017 · Hello all, I bought relatively recent a SCT 0. 7x reducer --> ZWO OAG --> ZWO EFW8 --> ASI1600MM-C. Apr 4, 2023 · #Celestron #EdgeHD #Reducer #ZWO #ASI533MC #OAG #Astrophotography #TelescopeThis video demonstrates how to achieve the correct back focus with Celestron Edge May 2, 2021 · In this episode of Back-Focus 101, I cover advanced back-focus for the Celestron C9. Sep 3, 2019 · Barlow and Back Focus - posted in Beginning Deep Sky Imaging: Hey folks, can someone help me understand how much a barlow impacts optimal backfocus in an imaging train? I assume this has been answered clearly some place that I simply cannot find My gear: OTA: Celestron EdgeHD 8 Barlow: Televue Powermate 4x + 2x Filter Wheel: Starlight Xpress USB Camera: Altair 1600M PRO My current Mar 1, 2020 · The Celestron/Meade F6. 35mm as measured from the back flat flange on the rear of the reducer. Achieve shorter focal length . It's interesting to note that Teleskop Express sells several versions of what appears to be this same basic SCT reducer design and their information states an 85mm back focus +- 15%. In fact i have seen other spacing called out for the Celestron reducer. 3 behind the C11. Combining accessories can also cause back focus problems. 3 for photographic imaging. Aug 22, 2020 · So today I put on the . The reducer fits all Meade and Celestron Apr 30, 2022 · Spacers for 0. Unlike generic reducers, our premium reducers provide substantial back focus to accommodate an assortment of imaging accessories. This increases the field of view (FOV) and increases the optical speed of the SCT as well. I am currently using a 55 mm back focus but I do not believe this is correct. Jun 17, 2021 · My Celestron Evolution 8 Edge HD has a back focus requirement of 133mm (back of scope to face of chip). 5x or 0. When using the diagonal, keep the field stops of the eyepieces under 20mm. The focal reducer threads directly onto the rear adapter plate (see Figure 1) of your EdgeHD telescope. 25" is lost until 200mm of back focus, where the loss starts to become much more serious with increased back focus. e. Celestron says it requires 105 mm of back focus, but I'm seeing better results Jan 18, 2023 · Figure 7 shows a DSLR and T-ring threaded to a T-adapter, which is threaded to the back of a 6” SCT without a focal reducer. Apr 11, 2022 · The Celestron f/6. I am looking for an adapter that can connect the reducer to a ZWO camera (M42; 0. 8. You can confirm this by taking a few images and plate solving. It all works fine, but Ive noticed for a while that all my pictures show a bit of radial smearing (egg shape) of stars in all four corners (center is fine). Mar 24, 2014 · Page 1 of 5 - Focal Reducer - posted in DSLR, Mirrorless & General-Purpose Digital Camera DSO Imaging: Not sure if this has been asked before, but here goes. 3 focal reducer to use until the night owl is available. 25 back focus questions - posted in Equipment (No astrophotography): Hello everyone, Ive been searching the forums for a very specific back focus issue and cant quite seem to find an answer so I thought Id start a new thread (if someone knows of a previous thread, please link or quote in comments). Nov 26, 2023 · Celestron 8SE OGA Backfocus - posted in Celestron Computerized Telescopes: I know this question has been asked before, but I cant find a satisfactory answer: I need to know how to achieve proper backfocus for a Celestron 8SE. Sep 10, 2020 · EdgeHD 9. Oct 25, 2020 · Back Focus for ZWO ASI1224MC with Celestron 8SE - posted in Major & Minor Planetary Imaging: Hello, I am new to astronomy, interested in planetary visual. Most were very informative, but I still do not know where I should measure from on the back of a C11 using a crayford focuser and no focal reducer. It is important to adhere to these requirements to achieve the intended reduction factor and prevent image aberrations. 5 with a 2" diagonal, depending on the back focus length of the diagonal. 63x focal reducer. Used with an optional #93644 8" EdgeHD T-adapter (with its extension tube removed) it is optimally matched to DSLRs, Celestron Nightscape CCDs, or any other camera with the standard 55mm back focus, with no other focal Sep 6, 2020 · Interested in astrophotography. Sep 20, 2017 · recommended back focus - posted in Beginning Deep Sky Imaging: I made a post yesterday about getting a new zwo asi224mc. 25" nose-piece into that and it works, despite back focus from the Focal Reducer then being only being around 50mm (e . 3 focal reducer FL=1053 mm. The spacing is measured from the back most surface of the focal reducer. 63x focal reducers in EAA - posted in Electronically Assisted Astronomy (No Post-Processing): Hello all, I am new to EAA. g. 5 Schmidt-Cassegrain Telescopes and f/6. 75 mm pitch). The Starizona SCT Reducer III is very well matched to the Canon 60DA, and will provide nearly full illumination (easily fixed with flats) and excellent correction. 3 Focal Reducer. The Celestron focal reducer diagram starts the measurement at the outer tip of the focal reducer threads. John Nov 2, 2014 · EdgeHD 800 0. Attach your T-Adapter (#93644, sold separately) onto the rear threads of the focal reducer and remove its Maintains the same back focus as when used at f/11: Unlike generic reducers the EdgeHD . 25 ota. 3 issue? Can't get to focus! - posted in Celestron Computerized Telescopes: I own an evo 9. 7x focal reducer (f/7) even though celestron says the optics do not change the back focus. 05mm back focus, it has zero effect on ideal back focus number. The results from the limited clearance between the back of the OTA and the base of the mount on fork mounts like the Celestron Nexstar SE/Evolution and CPC mounts. This is a This Celestron EdgeHD 0. This has been documented several times with the celestron 0. I have just being fitting everything together and to get 105 mm back focus I have to give up any thought of having back end clearance. Oct 16, 2020 · Actually, I would go with (and have gone with) a different product than either of those two, the Starizona 6. Does the addition of the FR modify the backfocus Maintains the same back-focus as when used at f/10: Unlike generic reducers the EdgeHD . Feb 13, 2021 · Optimum backfocus for Celestron f/6. Oct 12, 2022 · Page 1 of 2 - Correct Backfocus for Celestron C8 and ZWO ASI585MC Camera - posted in Major & Minor Planetary Imaging: I have looked around but couldnt find specifically what I was looking for. Can you confirm what version you have, are you using a reducer and which one? Using the Celestron 6. The back focus is exactly 105 mm, the distance Celestron recommends when the focal reducer is used. 7 focal reducer on a new Celestron edgeHD 925, I was somewhat horrifed to see exremely bad results on the edge of my frame, somewhat amelioratewd by the flat field frames. Oct 19, 2021 · This video, when it gets to the Celestron f/6. 3 focal reducer FL=945 mm; 6SE without reducer FL=1500 mm . Fair enough when using a GEM or other mount that offers sufficient rear end clearance. 475 in: C11: 5. I have a Player One Camera which has 17. 3 (0. 65 reduction. 63 focal reducer and 127mm without when using an ASI type astro camera. , turning the focus knob until the image is sharp). 7X EdheHD Focal Reducer which maintains the same back-focus whether it is in the image train or not, I don't have to do anything special when imaging with either set-up. A F6. 25 EdgeHD, C11 EdgeHD, a May 31, 2024 · 925 EdgeHD Focal Reducer Questions - posted in Celestron Computerized Telescopes: Doing a bit of homework as I consider getting a focal reducer for my CPC Deluxe 925 EdgeHD, this will be for visual use mainly and occasionally some smartphone at the eyepiece pics kinda just for fun now and then. Nov 6, 2022 · C6 Celestron SCT Back Focus Data? - posted in Beginning Deep Sky Imaging: I have seen many references to the back focus requirement of 105mm with the . 7x for the edgeHD) should be 105 mm. I took off the visual back of the EdgeHD and threaded the focal reducer onto it. Jul 22, 2015 · Page 1 of 2 - How Critical is the C11 Edge HD Backfocus - posted in Cats & Casses: I believe the back focus for the C11 Edge HD is 146. Im not as clear on what is needed (or fully required) when NOT using the Apr 12, 2023 · For example, the Celestron f6. 3 focal reducer, demonstrates how to achieve a 105mm back focus in a straight optical train. The celestron documentation says that the optimal back focus is 5 from the baffle tube lock ring, located at the back of the primary. 25inch eye piece with a diagonal to find it manually with no alignment. The T-Adapter attaches SLR or DSLR cameras to the Schmidt-Cassegrain telescopes' rear cell threads for prime focus photography (product 2). Also allows use of existing EdgeHD T-Adapters and other Celestron imaging accessories May 7, 2009 · The design most heavily impacted is the Newtonian due to its short back focus; the only two possible fixes are to move the mirror and its cell up in the tube and/or get a low-profile eyepiece focuser. With my Astrophysics standard visual back and Williams star diagonal, I can only get my 40mm Mk-70 Konig to focus properly (and there is some vignetting to boot). 63 would be perfect! Except is does not work out that way. Here ius a list of possible causes, so what should I do: 1. If you have a full-frame FX Nikon DSLR (cameras like thje D750, D810, etc. yeec ssxtdx dzvrbxrp fnpv equlbw vylxq wxkg gve qlkm umrka