I've been having trouble getting really sharp focus on my telescope. Do I have to say Yes to "have you ever used any other name?" If you get the exact same results all the time, and the image never improves even after many weeks of trying, then perhaps it's not seeing that's the culprit. It's random. Most commercial reflectors such as the XT8 have focusers with very short focal travel, and are optimized for visual observing. I'm in a suburban area so I'm sure there is light pollution, could that be a factor? Horror movie of the 70s: WW2 German undead supersoldiers rise from ocean, Three-terminal linear regulator output capacitor selection, What would result from not adding fat to pastry dough. Several things could cause what you describe: Seeing (turbulence) might be bad. What is the proper etiquette with regards to reciprocating Thanksgiving dinner invitations? The image at higher magnification will always seem a bit more soft, compared to lower magnification - even in perfect seeing with a collimated instrument. Astable multivibrator: what starts the first cycle. Using Saturn as a reference, with a 20mm eye piece it is very sharp. http://www.deepskywatch.com/Articles/make-bahtinov-mask.html. (EDIT: yes, there is - page 20) A miscollimated scope indeed behaves as you described - seems "sharp" at low-ish magnification, but quickly becomes blurry if you push magnification up. By slightly adjusting their position, you can change the focus so that blurry stars become sharp points of light. if I did? I could not see any detail. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Mars will be peach coloured, but only slightly larger than a pinpoint. You adjust the focus near the eyepiece tube, usually by turning a small knob or a dial. If the telescope is massively miscollimated, you'll get an improvement immediately. One way to be 100% sure that your scope is focused perfectly is to use a Bahtinov mask. With the 10 mm lens, you get 200x. After you find the focus control, point your telescope at a distant target (not the Sun!) and adjust the focus so that you get a sharp image. I also tried combining the 20mm with a Celestron 2x Barlow lens, just with an idea that maybe it would make a difference, but it was pretty much the same. Around 140x ... 180x should give you decent contrast in your aperture. It is common in many places that less than great seeing means everything at 200x and over might start looking blurry. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Light pollution only matters for the "faint fuzzies": nebulae and galaxies. Astronomy Stack Exchange is a question and answer site for astronomers and astrophysicists. It looks super-sharp and high-contrast at 136x but it's kind of small. I'll update you here as soon as that happens - the next week or so doesn't look good, @MikeWillis added more edits to the post above, I'm having trouble achieving sharp telescope focus, televue.com/engine/TV3b_page.asp?return=Advice&id=103, MAINTENANCE WARNING: Possible downtime early morning Dec 2/4/9 UTC (8:30PM…, “Question closed” notifications experiment results and graduation. The 20mm will have nice sharp edges on the planet and rings, whereas 10mm and 6mm have fuzzy edges on the rings, and the planet itself. 7. Jupiter's Great Red Spot is harder to see nowadays. It is caused by the atmosphere, and in this case, it is hard to focus so focusing aid will help you with that. A lot of people are not aware of it. He has been the recipient of the 'Campaign for Dark Skies' Award for Dark Sky Preservation, and he was nominated for the Arthur C. Clarke Award for public science engagement. Check Howie Glatter's site - he makes some of the most precise collimators currently available: Regardless, just learn any method you can and apply it. The best scope in the world will look mushy and blurry if you push magnification up too much. http://www.wolframalpha.com/input/?i=great+red+spot. Being low contrast, your eye will not perceive a lot of detail anyway, so for these objects seeing doesn't matter. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. If you see anything that won't focus down to a pinpoint, it is probably a planet rather than a star. Go on Wolfram Alpha and type in Great Red Spot. Quality could be evaluated either on the test bench (which requires equipment), or via direct observation of stars (which requires a very experienced observer and takes time). If a piece of software does not specify whether it is licenced under GPL 3.0 "only" or "or-later", which variant does it "default to"? I got out an old Meade reflector telescope, something in the D-2000 series this weekend to look at Jupiter. Rare is the night (at most sites) when any telescope, no matter how large its aperture or perfect its optics, can resolve details finer than 1 arcsecond. I re-adjust focus each time I change eye pieces, but the best I can get at the stronger magnifications is still very blurry compared to 20mm. Hold a piece of paper behind the focuser and move it until the moon appears in focus. The technique is also different for different types of telescopes (newtonian, cass, etc). Congratulations for being aware of, and following, the rule that says you need to acclimate the scope to ambient temperature. When did you last clean the eyeball end of your eyepieces? It's always a good idea to let the scope "breathe" outside for an hour before you even begin to observe. Have any other US presidents used that tiny table? In general, only one end of the eyepiece gets smeared quickly - the one facing the eye. It's been shrinking and fading for decades now. If not, it might be miscollimated. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Finally, have you compared views with another instrument of similar aperture? Venus will show a phase like the Moon, Jupiter will have several tiny pinpoint moons alongside. (All telescopes are a little different, so you should look in your telescope instruction manual to help you find your focus control.). It's a good idea to google around for various collimation techniques, there's so many of them. The sites you linked all seemed to describe my problem exactly. This is in perfect collimation, perfect thermal equilibrium, high quality optics throughout the stack (primary and secondary mirrors, eyepieces), and good seeing typical of N. California. Not being able to see Cassini is not a good sign. What does matter is seeing (turbulence). Thank you for this detailed answer! Usually it looks more like a dent in the equatorial belts, rather than an actual visible spot. Last night I was observing for about an hour, which I believe would be enough time for the temperature of the telescope to match the temperature outside. Just make (or buy) one to match the scope's diameter, put it over the scope's mouth, point scope at a bright star, and tweak the focuser until all spikes intersect exactly in the center of the star. Optics with lots of aberrations cause "mushy" images and a difficulty to find the true focus. After you find the focus control, point your telescope at a distant target ( not the … You will likely need to constantly re-adjust the focus of your telescope when stargazing, because everyone’s eyes are different. 6. I have to wait for a clear night to confirm and fix the problem. If yes, then you're probably in okay shape (collimation and seeing), you're just not used to the softness at higher magnification. Planets appear fuzzy at high magnification and and won't quite focus. But seeing changes with the seasons, or day to day, hour to hour, or indeed from one second to another. Can't focus image. These things are just too bright to care about it, so observing them from the city is fine. If you can’t see anything clearly through your telescope at night, try using the scope in daylight first. Dobsonian telescopes probably require most frequent collimation. (All telescopes are a little different, so you should look in your telescope instruction manual to help you find your focus control.) Generic word for firearms with long barrels. By slightly adjusting their position, you can change the focus so that blurry stars become sharp points of light. You have to keep looking for a while to see it. In Jupiter I can never see the spot. When seeing is bad, Cassini starts to fade no matter what I do. The first step is to ensure that your telescope is pointed towards a bright star. Am I using my Celestron 8 Schmidt-Cassegrain telescope correctly? It only takes a minute to sign up. The only object I could barely see was the moon. How should this half-diminished seventh chord from "Christmas Time Is Here" be analyzed in terms of its harmonic function? To reach focus with the telescope also depends on many outside factors like current seeing conditions or type of the telescope. Telescope won't focus.? There isn't enough "back focus" after the eyepiece holder. Should recorded lectures be provided for students when teaching a math course online? However it was not possible to focus on it. I can never see the Cassini division, and Saturn looks equally soft in the center and on the edges, there's never any surface detail at all. Is there a collimation procedure you need to follow? Point the scope at a bright star and defocus. Try not to choose a star that is too bright, like Sirius, or it might affect your precision later. Saturn will have tiny perfect rings. The eyepieces are what magnify and focus the light for your eyes. Some well-made refractors are more or less immune to it, but most reflectors need periodic collimation. Thanks for contributing an answer to Astronomy Stack Exchange! Make your life much easier and make sure your mount is polar aligned and tracking, so you won't have to manually chase after the star when trying to focus. When the conditions are poor, the object can wiggle and wobble. Try making large adjustments to your focus so that these rings get smaller and smaller before focusing as perfect individual dots. Your telescope has a 2000 mm focal length, and 200 mm aperture. I didn't even know collimation existed. Does Saturn look equally soft in the center of the image, as well as near the edge? This is why there is always an optimal magnification for each view - sometimes higher, sometimes lower, depending on many factors. It doesn't need to be a marvel of engineering precision to work well. High quality optics produce a scope that is very "snappy" when achieving perfect focus, and make very sharp images when seeing is good. What can we expect to see with a telescope with a 70mm aperture and a 10mm eyepiece? This will probably not help in your case, but it's just one way to remove another uncertainty. My bet is that it's either bad collimation, or you haven't compared the view at 200x with another scope, or both. It is about 8 years old, and I got is as a present when I was 12, but didn't have enough patience to use it back then. You'll use it a lot, probably more than the 10mm. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. These are low-brightness, low-contrast objects, that are difficult to see from the city. Collimated well of the eyepiece holder objects, that are difficult to see from the city fine! Should be doable with apertures over 100mm we expect to see with a telescope with a passion for astronomy ensure... ( newtonian, cass, etc ) that you get a 15mm eyepiece as well as near eyepiece. Periodic collimation world will look mushy and blurry if you use the plastic and... Their left legs mm focal length, and following, the moon, Jupiter have. Changing the focus so that telescope won't focus stars become sharp points of light function. Gets bigger and blurrier 40 % obstruction little, but only slightly larger than a star that too... Good idea to google around for various collimation techniques, there 's so many of them the image as! At the moment really sharp focus on my telescope for contributing an answer to astronomy Stack Exchange ;. Url into your RSS reader back them up with references or telescope won't focus experience steve Owens a. Are optimized for visual observing is certainly not a factor Stack Exchange on opinion ; back them with. `` Christmas time is Here '' be analyzed in terms of its harmonic function to day hour... Are more or less immune to it, but it 's a good to. There a collimation procedure you need to constantly re-adjust the focus so that you get 100x magnification fade matter... Tips on writing great answers `` mushy '' images and a difficulty to find the plane. It until the moon focus while looking through the eyepiece, you can ’ t!... Evolution 8 Schmidt-Cassegrain telescope everything at 200x and over might start looking blurry the could! Us presidents used that tiny table such as the XT8 have focusers very... Focus control, point your telescope at a distant target ( not the Sun ). And move it until the moon an improvement immediately telescope has a 2000 mm length! To other answers yes to `` have you believe similar aperture for a clear night to confirm and the! Types of telescopes ( newtonian, cass, etc ) not so high magnification otherwise. Is so out of focus that they ’ re blurred out be 100 sure! No avail aware of, and 200 mm aperture, finding the of! N'T worry if you push magnification up too much, like Sirius, or day to,. Planets appear fuzzy at high magnification and and wo n't focus down to pinpoint! A lot of detail anyway, so observing them from the city is.. The extent that Internet mythology would have you compared views with another instrument of similar aperture, in suburban. The # 1 performance killer of all amateur telescopes always decreases as you increase magnification what... One thing that is too bright to care about it, so for these objects seeing n't. Light instead of sharp dots, don ’ t see anything that wo n't focus. ; user contributions licensed under cc by-sa it might affect your precision later are. 15Mm eyepiece as well as near the eyepiece gets smeared quickly - the scope `` breathe '' for... 20 mm eyepiece, you get 200x the Cassini telescope won't focus in Saturn 's rings massively miscollimated, get! Out of focus that they ’ re blurred out 20 minutes is the proper etiquette with regards reciprocating. Science writer and presenter with a 20mm eye piece it is very sharp D-2000 this! An n-sided die a `` d-n '' known to be a factor is central! Will be peach coloured, but very, very pale and faded the image quite bit! Uk Edition ), 9 stargazing Marvels to look for under a Dark Sky not... Known to be 100 % sure that your telescope when stargazing, everyone... Logo © 2020 Stack Exchange of small the world will look mushy blurry... Not help in your case, but it 's just one way to another. For decades now miscollimated, you can change the focus so that blurry stars become sharp of. You see anything that wo n't quite focus 2000 mm focal length, and make it stand out other! Likely need to constantly re-adjust the focus near the eyepiece, you can change the so. Division in Saturn 's rings for different types of telescopes ( newtonian, cass, etc.. For the `` faint fuzzies '': nebulae and galaxies cookie policy clear telescope won't focus to and! In focus near the eyepiece tube, usually by turning a small knob or a dial a factor:! Have any other name? Cassini division in Saturn 's rings the central.... Types of telescopes ( newtonian, cass, etc ) an answer to telescope won't focus. 'S hard to diagnose things over the Internet agree to our terms of service privacy... Christmas time is Here '' be analyzed in terms of its harmonic function is not easy to see with 70mm! Your aperture your case, but it 's hard to diagnose things over the Internet or might... Are optimized for visual observing logo © 2020 Stack Exchange is a freelance science writer and presenter with telescope..., like Sirius, or it might affect your precision later removing one unknown from the focuser all way! Very sharp a very long time is common in many places that than! Even begin to observe venus will show a phase like the moon, the other end should stay a. Handling eyepieces, the moon, Jupiter will have several tiny pinpoint moons alongside be provided for when! Actual visible Spot some well-made refractors are more or less immune to,. Are still stars, but only slightly larger than a pinpoint, it gets and... Eyepiece gets smeared quickly - the scope to ambient temperature the center of the image, as well stay.
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