Best telescope back focus calculator. You can use FocusCraft and Focusing Aid.
Best telescope back focus calculator Aug 27, 2021 · How do you measure your back focus? - posted in Equipment (No astrophotography): I have always wondered how you guys calculate or work out the right back focus distance in your setups. Focal reducers also reduce back focus and, when used for prime-focus photography with Dec 15, 2018 · The 12" SCT has a huge back-focus range ! How much back-focus do you need? Begin by turning the knob fully clockwise - that pulls the primary mirror all the way back and focal point all the way in. In this section of our best telescope 2025 reviews you will land a decent beginner-level telescope. 3-inch) Galileo telescope, it is 1,100 mm. Essentially my understand is that the back focus is the distance from the last optic element to the sensor. In the beginning of my astrophotography journey, i just went with the standard 55mm which seems to be a standard measurement for more or less every OEM corrector/reducer. 4km All values are approximate and purely theoretical under ideal observation conditions. (SVBONY Fixed Diameter 65-100mm)If you are not interested in buying a Bahtinov mask, there are several free tools available online to help you make your own Bahtinov mask, including tutorial videos that help you build the correct size for your telescope or lens. 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. Buying a Good Telescope. The recess on the ASI2600 is 17. Jan 2, 2025 · Images I have captured using the RedCat 51 refractor telescope. If you are using Focusing Aid switch to 1:1 Preview mode (double click on the star you want to use). Eyepieces come in a range of focal lengths from 3 mm to about 50 mm. Incorrect back focus can lead to blurry images or the inability to achieve focus at all. Feb 4, 2017 · A simple Bahtinov Mask design. The 8" Dobsonian telescope is the most recommended beginner telescope - just about anyone in the hobby will recommend one. He tells me Meade never published the data but Im hoping someone might have figured it out already. Telescope focal length increases 15%. 1. 4 mm of aperture and 2,794 mm focal length at f/10. May 9, 2022 · Page 1 of 2 - Backfocus C11? - posted in Cats & Casses: Hello all, I just saw in a YT tutorial that a Celestron C11 has a backfocus of 146. Some are examples from my telescope, a C11 SCT with 279. Determined by the telescope's focal ratio, the CFZ is narrower in faster (lower f-number) telescopes, demanding precise focusing to capture clear, detailed images of celestial objects. I've read and seen videos saying that you have to get the back focus exactly right to achieve a sharp focus on the imager. Visual Mode Imaging Mode Binocular Mode Choose Object. Its rare that I commend Celestron, but they actually have a very clear diagram that shows the back focus with Feb 1, 2024 · Ok, now that we’ve talked about some of the more general points that determine which is the best telescope for your needs, we’ll look at the specific factors that the best telescopes have. (0. I need to know exactly where it should be to begin with. See the image further down the page for more info. 5 mm of back focus with the ASI533MC Pro camera. 142857142857×158=22. What telescope do you have? Aug 21, 2020 · Page 1 of 2 - Back focus of SCT - posted in Cats & Casses: Hi, this is a newbie basic question. So I can't just put the barlow into the back of the OTA and move the focuser until it comes into focus because it would change the effective focal length. Messier: Solar System: Dec 28, 2023 · Back focus is the distance from the last optical element of your telescope or accessory (such as a field flattener or a focal reducer) to the focal plane. 2) A lens or telescope has Backfocus requirements in millimeters. Thankfully, ZWO provides a detailed back focus guide to achieve the recommended 55mm back focus of the ZWO ASI2600MM Pro. As with any dedicated astronomy camera, reaching the ideal back focus is critical to maximizing your results. 6. That's the reason why the highest-powered telescopes are such monsters with huge mirrors. Feb 25, 2021 · Edge HD back focus - posted in Celestron Computerized Telescopes: Hi, Heres a recent support thread from Celestron. celestroducer-corrector Dec 18, 2020 · 45° Erect Image Diagonal recomendation. Yes, the 0. My Aug 27, 2021 · Procedurally, if the back focus distance isn't known but the reduction factor is, am I safe to test at two or more different distances, platesolve to establish the achieved focal length at each distance, and calculate the back focus distance that gives the required reduced focal length? (in my case, 2032mm x 0. 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. The focal length 805mm. Determining this distance can b Flange back focus distance = 44 mm T-ring adapter for EF/EF-S mount back focus = 8 mm. IBF = 44 + 8 = 52 mm back focus (low profile configuration) Notice: T-ring adapters for most cameras are designed and made to lead to a 52mm back focus distance (like here for the Canon EOS). e. Does this happen with yours? What do you do about it? If I dont fully seat my 2 diagonal and eyepiece I can get to focus, but that doesnt make me very happy. 56mm • Light area: 122. /Ira Mar 3, 2017 · And so when employing accessories (such as 2" diagonals, filter wheels, etc. Understanding back focus is crucial for sharp, focused astrophotographs. This measurement in millimeters, is the distance the sensor is set back from the face plate of the camera. 63x SCT Reducer requires a backfocus of 105 mm, measured from its Metal Back to the sensor plane of the camera. 75 mm pitch). 5mm — the difference being the 5mm thickness of the tilt adjustment ring. Sean Walker / Sky & Telescope Shop Telescopes, Accessories & Mounts at High Point Scientific. The included 2-inch field flattener guarantees veracious sharpness, making it perfect for broad 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. Aug 3, 2018 · Calculating Backfocus - posted in Beginning Deep Sky Imaging: I am extremely new to imaging and could use a bit of help. Its advanced FPL 53 optical glass virtually eliminates chromatic aberration, ensuring crisp, infallible images of celestial objects. 3 focal reducer/corrector on a 6SE OTA? Ive seen the number 105mm in a few places Mar 10, 2021 · Help me understand Backfocus in plain English - posted in Experienced Deep Sky Imaging: These are the two facets to Backfocus as I understand (or misunderstand) them today. Proper back focus depends on your telescope, camera, and any additional optics. Feb 10, 2023 · The Askar FRA500 is a compact beginner refractor telescope with an aperture of 90mm, a focal length of 500mm, and a focal ratio of f/5. Then, add up the spacing distances of all of your pieces in your optical train to your sensor. Attaching the Askar field-flattener/reducer will turn this telescope into a wider and much faster instrument, more info on May 31, 2024 · As you can see, the magnification of the telescope gets greater when the focal length of the objective increases or when the eyepiece's focal length decreases. We moved the scope to an observatory and He cant remember the distance needed for focusing or, not sure if it has it, backfocus. Specifically i am planning to use the SkyWatcher EVOSTAR 72ED DS PRO Jul 27, 2021 · Changing the distance from a barlow lens to the sensor changes the magnification. Back-focus in astrophotography. I recently picked up an ASI1600 MM cooled camera, the ZWO Filter Wheel, and have the following scopes: ES 80mm f/6 refractor Meade ACF LX600 12 (305mm aperture, f/8) Do I need to add spacers if I have the 1600 at prime focus? I know that if I were to get a field flattener Sep 21, 2022 · With tilt adjuster attached, the diagrams show the back focus distance is 17. They hit a great balance between size, portability, and value. 3 out of 5 stars 20,807 Nov 9, 2020 · The Barlow lens will extend the position of the primary focus plane out of the back of the telescope, as compared to its original (non-Barlow) position. Combining accessories can also cause back focus problems. 2X, and ZWO2600MC Pro with Filter Drawer, and was having lots of issues with back focus. Apr 4, 2022 · When used to connect to M48 tubes, this adapter consumes an additional 4 mm of back focus. com Search the Oct 27, 2022 · Focusing a telescope may be, at times, challenging, as every telescope has a different focuser, and there could be slight differences in the procedure. The focal ratio telescope calculator is straightforward and can be a helpful tool for determining the optimal focal ratio for a given telescope. Worry not! Today, you will learn how to properly focus your telescope and make the experience of viewing the starry sky a better one. 5 mm This will calculate the focus tolerance you have achieved. If you are shooting through a telescope or telephoto lens, either equatio will be perfectly fine. Aug 27, 2021 · Procedurally, if the back focus distance isn't known but the reduction factor is, am I safe to test at two or more different distances, platesolve to establish the achieved focal length at each distance, and calculate the back focus distance that gives the required reduced focal length? (in my case, 2032mm x 0. This factor is designated by a power that is less than 1, and it usually lies between 0. I have a Celestron 8SE on a SkyWatcher EQ6-R Pro mount. See full list on agenaastro. It doesn't work on my C9. 5mm back focus, and eventually a filter drawer with 21. Calculator Instructions. For this 135 mm (5. Apr 13, 2022 · It uses approximately 3. Telescope used like telephoto lens; Field Angle = (Image Diameter ÷ Telescope Focal Length) x 57. Does the back focus point of a SCT telescope change position at all with the movement of the primary mirror? Or does the back focus length only have meaning when focusing at infinity? Thanks jk Feb 29, 2020 · Accurate focus is critical to obtaining high-quality CCD images. 8 x) with 55mm back focus, a ZWO ASI294MC pro cooled cmos imager with 6. I always though that a telescope didnt have backfocus, but only items like reducers. SkyPortal App. Sep 20, 2017 · recommended back focus - posted in Beginning Deep Sky Imaging: I made a post yesterday about getting a new zwo asi224mc. 05mm, then how comes Im able to get focus at less than this distance? Would there be a difference in details when The Auto Focus Aid needs a source of HFD / FWHM / InvPower values. One of the mistakes frequently made by beginners is starting with too high of a magnification. Oct 7, 2021 · 11 Ways to Fix Telescope Focus Problems Start with a low magnification. Optimum back focus distance (T-Ring shoulder to focal plane) is 56mm. 5mm of that. 5mm from tilt plate. Beginning from the camera end, we do this: Consume 6. l. It seems like such a small detail, and it might be, but it will save you from unexpected scratches, stains, and misaligned lenses. So, now we know what 17. How would a person go about figuring out what the recommended back focus is. This is known as the Rayleigh’s limit. 0 • Moon features: >5. Mar 4, 2020 · For the RASA 8, very short 29mm back focus (25mm with included M42 T-adapter), which can limit options for using filters with some cameras; Critical Focus Zone for RASA scopes is ~8-10 microns in depth, which can make accurate focusing more challenging, especially if the temperature shifts significantly during the night May 13, 2021 · This will ensure that you are closer to focus when you bring your scope out for an imaging session. Simply input the model of the telescope you plan on using to find out which solar filters will fit properly. I want to attach a flattener/reducer (Astro-Tech 0. Highlight the numbers already entered in the boxes and delete them and enter your own. In a nut shell it is the smallest angle for which two star diffraction patterns (Airy disks) can Feb 13, 2021 · Configurations and Back Focus. So as the title implies, how do i calculate whats the back focus that i need for a specific telescope and camera. It seems it lacks about an extra inch of back focus to bring most of my eyepieces to focus. The diameter is the same as their regular Astronomical telescope, but the tube is extended so near focus is a matter of feet instead of Yards or meters. 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. This makes it more difficult to get the telescope’s focus dialed incorrectly, so always start with low power (low magnification) and work your way up slowly. Calculate the focal length of your telescope. The distance between the rear of your telescope and the point where light is focussed is known as back-focus measurements. Magnification (power): The amount that a telescope enlarges its subject. In other words, you rack the focuser all the in or all the way back but can not acquire sharp focus. Feb 2, 2021 · Back focus calculation - posted in Beginning Deep Sky Imaging: Hello everyone, So i think decided on what telescope and camera i should get for AP but i dont know if theyre compatible right out of the box. Back focus is important because some accessories require a specific back focus distance to work properly and correct optical aberrations such as coma or field curvature. The user does some arithmetic (back focus- sensor recess on camera = spacers required. I have checked collimation and that appears to be fine so someone has suggested there might be a problem with the mirro Feb 25, 2021 · I've been playing around with Meade ACF with a Lepus Reducer 6. This is the distance from the camera's internal optical sensor to the face of the camera. Im not entirely sure that I got an answer, but still r. The telescope can be used with full-frame cameras, and the built-in reducer/flattener means you do not need to calculate the back focus. Apr 9, 2017 · Page 1 of 3 - Telescope Simulator & Eyepiece Set Calculator - posted in Eyepieces: Hi all ! As I am currently translating my Stelvision personnal website, I am glad to present you the English version of an online tool which is beginning to be well known in France: a telescope simulator & eyepiece set calculator. Is their a sticky explaining how you get the recommended back focus? How would you calculate in a focal reducer Jul 23, 2023 · Meade LX200 EMC, 10" back focus with no reducer - posted in Meade Computerized Telescopes: I have a 10 Meade LX200 and Im trying to put a Crayford focuser and and OAG onto it but I cannot find any info regarding the back focus distance for this scope, or where exactly its measure from. Sep 26, 2024 · How many solutions are there for ASI6200MM Pro to get 55mm back focus length? If you are still stressed with these problems, then this tutorial is exactly what you are looking for. (The standard nose piece supplied by ZWO is 30 mm in length). 05mm. Gskyer Telescope, 70mm Aperture 400mm AZ Mount Astronomical Refracting Telescope for Kids Beginners - Travel Telescope with Carry Bag, Phone Adapter and Wireless Remote. Its purpose is helping beginners to get an idea of what they can see in an amateur A Barlow Lens, placed between the eyepiece and the telescope, will increase the Resulting Magnification by the power of the Barlow; i. Aperture: Calculate the focal ratio of your telescope. ) which force the focus to lie farther back than nominal, best to *mesure* the exit pupil for the non-reduced configuration rather than rely on the nominal f. To this point, we have used 48. 8x. Aug 31, 2017 · In most telescopes the focal length is roughly equal to the length of the tube. 63 reducer/corrector - posted in Beginning Deep Sky Imaging: Apologies in advance, Im sure this would have been discussed before but Ive searched to no avail Could someone help explain how to calculate the optimal back focus/spacing for the Celestron f/6. Calculators already have sample data in them. Focus by eye as good as you can or go to know focuser position which is close to the best focus point and click on the button Run. The focal length of the objective usually goes hand in hand with the length of the telescope itself. Using adapters only *This solution needs the M48-M48 16. This includes the depth from the front of your camera to the chip itself, the depth of a filter wheel or off-axis guider, and the depth of any Feb 2, 2021 · Back focus calculation - posted in Beginning Deep Sky Imaging: Hello everyone, So i think decided on what telescope and camera i should get for AP but i dont know if theyre compatible right out of the box. An example is Questars 90mm Close up lens. 142857142857 . Celestron’s FREE planetarium app is an astronomy suite that redefines how you experience the night sky. This is Focal Length Calculator. The Critical Focus Zone (CFZ) of a telescope is the range within which the focus is acceptably sharp for astrophotography. This adds The choice of barlow depends on telescope, camera/pixel size, and cheap barlows reduce the contrast). (However, as mentioned previously, most Newtonian reflector telescopes will need a 2x Barlow or an amplifying lens for the binoviewer to reach focus. So for best performance you want the primary-secondary mirror spacing at the design position. Barlow Power The Critical Focus Zone: A common and popular figure of merit for focus accuracy is the Critical Focus Zone (CFZ). Apr 28, 2020 · 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. I appear to have really bad coma at 105mm backfocus. One or two 2” extension tubes provide the required additional focusing way. Heres my attempt: 115÷805= . Use the bright star (Acrux A) for focusing, with live view enabled and zoomed in as much as possible showing both stars. The back focus is 158mm. Back focus is a little different on a Rowe-Ackerman Schmidt Astrograph (RASA) t Our calculator, at typical seeing of 2-4”, uses the Nyquist formula of 1/2 and the 1/3 to stop stars becoming square so the optimal range is between 0. Using Telescope Eyepieces. They are simply the best bang for the buck. Mar 27, 2024 · With these no fuss telescopes, as long as you can reach focus, the entirety of the image will be in focus as well. 3 Reducer (https://www. 67 = 2 / 3, 2 = 4 / 2). 10 of the Best Astrophotography Telescopes Available Today. Jun 10, 2024 · Created By: Noctua Software Operating System: iPhone, Android Category: Planetarium Paid or Free: Free, Paid Pro Version Description: “Stellarium Mobile is a planetarium app that shows exactly what you see when you look up at the stars. This support for full frame imaging allows you to add the vast Apr 10, 2021 · Correct procedure for setting focus and back focus with an SCT reducer - posted in Equipment (No astrophotography): Hello all. Failure to do so can result in serious damage to your eyes and the optics of your telescope. Feb 12, 2024 · Backfocus or focusing on a classic 12" LX200 - posted in Meade Computerized Telescopes: Hi, My brother has a classic Meade LX200 12 that he was using in Florida. I use this camera with a ZWO 7-position filter wheel with 36mm filters. 5mm back focus refers to the camera with the tilt plate and the 12. Depending upon your telescope (smaller aperture and faster f/ratio telescopes are more difficult to focus) and the quality of your focuser, you should expect to achieve a focus tolerance under 10 percent, perhaps as little as 1 percent - smaller is better. Jul 6, 2017 · What is Backfocus? In the simplest of definitions, it is the ability or inability of the focuser to bring the image into sharp focus be it through your eyepiece or your CMOS camera. 4. My original question was to ask what the expected focal length of an Edge HD 8 was, so that I could plate solve back to the right length in alternate image trains. You can use FocusCraft and Focusing Aid. It should really just be a 2" visual back at the back of the scope, the barlow, and then the camera (and yes, that will reach focus). Adjusting back focus involves precise measurements and careful equipment setup. My goal for this article is to help you choose a telescope for photographing the night sky, and provide my expert (hands-on) experience with some of the best models available. For example my personal favourite is Acrux. The flattener needs 95mm. 93" • Limiting magnitude: 13. They are based on the FR being placed in its designed position at the back of the SCT: Moving mirror SCTs require special treatment because their focal length changes (lengthens) as you adjust focus to compensate for the in-focus required from inserting the focal reducer in the optical path. Sep 23, 2023 · Like telescopes, eyepieces have a focal length, which is the distance at which they focus the light that enters them. We strive to offer you high-quality telescopes and telescope accessories at low prices without skimping on customer service. It is highly recommended that you focus your dedicated imaging camera first and then achieve focus with the OAG. So, if you are shooting focal lengths of 50mm or shorter, the ATAN equation will give more accurate results. And changing an SCT's focus changes it's focal length. Read our guide! Field of View Calculator Test different telescope, camera & eyepiece combinations. 5" of back focus—sufficient for catadioptric telescopes (Schmidt-Cassegrain and Maksutov-Cassegrain), as well as a good number of refractor telescopes. A refractor has a fixed focal length, the distance from objective to the focal planed, and no back focus requirement. Celestron RASA Back Focus - How to Calculate Back Focus - What are my Options. If you have one those those latter telescopes, you can artificially extend your back focus using a lower magnification Barlow lens You can also find the back focus of your ZWO camera in this document: link (Excel, easier to view) or link (PDF, three pages). 5x or 0. To make these telescopes even more user-friendly, their image circles have a diameter of 43mm (the minimum diameter needed for use with full frame cameras) or greater. Manufacturers will give that optimal position as the back focus--the distance you want the sensor behind the back of the telescope. Someone mentioned recommended back focus, a google search revealed nothing helpful. Contacted Meade, OPT, Lepus, and was informed by all that back focus should be between 105mm and 110mm with 110mm supposed to be optimum. 5mm and when off it is 12. The CFZ is related to the telescope angular separation under diffraction limited conditions. Adding extensions tubes before the diagonal can correct situations where you need more backward focus, but for Nov 20, 2021 · Understanding back focus - posted in Beginning Deep Sky Imaging: Im upgrading to a ZWO 1600MM and Im trying to understand what Id need to achieve the correct back focus for my setup - but Im struggling to fully understand what it is - or more specifically why its so important. 5mm extender and the M54-M48 21mm extender. However, there are still some tricks to getting a precise focus. Without a star diagonal, viewing objects can be uncomfortable, and you literally might not be able to use your telescope as the eyepiece may not be physically accessible or able to reach focus without a diagonal. However, if you now focus with an eyepiece, the eyepiece focal plane (usually the field stop) will then coincide with this new primary focal plane. The camera kit takes up 63. Okay, I'll walk away from the chalk board now. Formula: Aperture X Focal Ratio . Formulae used for these calculators Feb 3, 2017 · Near focus is usually set to the Practical distance of the design of the Telescope in question. - posted in Beginners Forum (No Astrophotography): I was browsing for lenses and possibly a replacement diagonal and came across this item Celestron 45-Degree Erect Image Diagonal https://www. 2 days ago · Sit back, relax and let this best goto telescope track your celestial object! This is the best way to view the night sky. com Jun 26, 2022 · The back focus is specified by the manufacturer, no calculation is on the part of the user. (mostly 55mm). It’s equal to the telescope’s focal length divided by the eyepiece’s focal length. and the base 20-25 lbs. This is a Sep 9, 2014 · Page 1 of 2 - Considering filter thickness when calculating backfocus - posted in Experienced Deep Sky Imaging: Im confusing myself here and could use some clarification. First is a Meade Series 4000 f/6. 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 Jan 25, 2021 · Focal length is the large number you'll often see printed or engraved on the front or back of the scope, usually between about 400 and 3,000 millimeters. Let’s now look in more detail at the factors for choosing the best telescope given above at the beginning of this article. gooday@btinternet. My telescope has sufficient travel way but I still use extension tubes because it keeps the, relatively heavy, focuser tube more inserted. I believe the correct back focus for this unit is 1 day ago · 2025’s Best Amateur Telescopes – Full Reviews. It may or may not help. ) “When using long focal lengths and manual focusing I find it best to focus on a very bright star that has a not so bright companion. 57142857142 So, if this is correct, the image circle at Feb 16, 2022 · I hope someone may be able to give me the correct figure. for calculation, if high accuracy is desired. if the calculator shows that a certain eyepiece gives 100x in your telescope, and you add a 2x Barlow, the resulting magnification will be 200x (100 x 2). Heres the equipment I want to use for DSO imaging: Celestron f/6. Pointing towards the moon or a star-rich area of the sky is a perfect way to dial in your focus even further. 5 mm of back focus. At High Point, our goal is to coach and nurture aspiring amateur astronomers and astrophotographers like yourself. . In the later years, I have been more and 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. But it's very dificult to use an 2600MC Duo with the C8 because the camera needs 42mm opening diameter. Feb 13, 2022 · Never attempt to collimate, focus, or adjust back focus during poor seeing conditions or while the OTA is equalizing to outdoor temperatures. Specifically i am planning to use the SkyWatcher EVOSTAR 72ED DS PRO Sep 10, 2023 · The back focus for your telescope imaging train is the measured distance from the last optical component at the back of the telescope, whether it’s a coma corrector or field flattner / focal reducer and the focal plane of the telescope where the camera detector is. 25 as well. The Apertura 60mm FPL 53 Doublet Refractor, with a 2-inch field flattener, is an accurately constructed telescope designed for astrophotography and visual observation. Mar 27, 2022 · A good telescope cover is essential to maintain a telescope performing at its best. 67” and 2”. Dec 14, 2023 · Star diagonals are a necessary part of any Cassegrain or refracting telescope with an eyepiece at the back end. 7 cm² • Light gathering power: 319x • Angular resolution: 0. An added complication is including a reducer or other additional corrective optics. Field 5 in the calculator is the sum of the back focus and the length of your camera’s nosepiece. The SCT Back focus distance from primary mirror baffle tube lock ring for the C8 is 5" (12,7cm) and the 2600MC Duo Back focus is 17. Im trying to determine the correct backfocus for a flattener with my system, taking into account the thickness of the filters. Some telescopes use extra lenses and/or mirrors to create a long effective focal length in a short tube. There are five connection solutions for ASI6200MM Pro. You first need to know the metal back distance requirement of your telescope or corrective optic piece. • Prime focus magnification: 29x • Re-focus distance: 1. For large numbers, do not use commas. which I think is digital, Do not use digital zoom DSRL They aren't ideal for planetary imaging but of course the best equipment is the stuff you already have :-) DSOs You need a tracking mount for DSO. In summary, we are using Nyquist as a starting point, with a slight tweak, because we are typically sampling very small, circular, stars. Guider SX lodestar (any version) optical back focus = 12. Then turn knob counter-clockwise to push the primary mirror forward and push the focal point further out the back . 5mm back focus is without the tilt plate. That would leave an adapter Mar 25, 2015 · Back focus on Explore Scientific 127 APO - posted in Refractors : I just got a new ES 127 APO. 5mm back focus. Any Oct 30, 2005 · The two equations agree for focal lengths down to around 50mm, then they start to diverge. To use the calculator, you need to input the focal length and aperture of the telescope, and the calculator will calculate the focal ratio based on this information. With over 150 years of combined experience An infinity focus on a camera lens means that light rays flowing into the camera sensor are parallel and arrive as points. 63 = 1280mm) Jun 26, 2022 · The back focus is specified by the manufacturer, no calculation is on the part of the user. Generally speaking, if I'm adjusting my telescope optics, I let the scope equalize outside for about two hours. The focal length is often found on the front or back of the telescope. Note: Since this is the Basics section, the following discussion keeps focusing simple and describes the easiest and best ways to focus Mar 6, 2024 · THE FOCAL RATIO TELESCOPE CALCULATOR. 5mm. The main lens is 115mm. That being said, this configuration may make it impossible for the 8SE to swing high enough to image the planets since the fork arm doesn't give a lot of space between the back of the scope and the base. 63 = 1280mm) Nov 4, 2012 · Take control of your telescope! Download the Celestron PWI Telescope Control Software. The powerful 5″ GoTo Mak-Cass has a long 1540mm focal length for amazing views of the Moon, planets, and deep-sky objects. Or setup with eyepiece at same Jan 7, 2021 · If the eyepiece connects in the middle or in the upper half of the body of the telescope (like most reflectors/Newtonians), your telescope has a low back focus and you might not benefit much from a binoviewer. What is telescope back focuswhy is it importantand how do you set it correctly?Having the proper back focus between your telescope and camera is critic Our calculator, at typical seeing of 2-4”, uses the Nyquist formula of 1/2 and the 1/3 to stop stars becoming square so the optimal range is between 0. If there is indeed a backfocus of 146. 3° For Dobsonian/Newtonian, use Paracorr to correct coma. These conditions create very inconsistent and funky-shaped stars. Feb 4, 2022 · Just looking at this calculator, but I assume it just is programmed with the correct back focus for a certain setup of camera, FW with a certain corrector or flattener, then adds on 1/3 thickness of the filter and then gives you the remaining spacers needed to make up that back focus, so nothing different to manually adding up all the elements and doing a bit of maths. That's why our experts have created this solar calculator to help make things easier. You will see some trade-offs between aperture and equipment quality. The telescopes weigh roughly 20-25 lbs. This guide will help you understand and compare the most popular telescope covers so you can pick the one that is right for you. Your eyepieces are the first accessories you should learn to use with your telescope. One of the many advantages of CCD imaging over film astrophotography is that achieving focus is much easier with a CCD camera. 3 SCT focal reducer/corrector. The guide sensor is very vigneted. celestro-image-diagonal That sounds like a great piece to replace my stock diagonal, specially if it correct the images being upside <> down / right <> left I Jun 5, 2022 · Image circle size calculation? - posted in Beginning Deep Sky Imaging: How do you calculate image circle size for a telescope? I am trying to determine the circle size on an Orion EON 115mm triplet. Oct 13, 2011 · The required length can exceed the telescope’s focuser travel, which will render the projection out of focus. Mar 22, 2018 · Page 1 of 2 - Calculating back focus for Celestron 0. 1) The camera has a Backfocus measurement. I have been trying to image using my C8 with fr and asi2600mc pro. caqzkkxsrlrecedahxjecoiyxfmwgcnmkothhrisurzprmvnhrjy