Why is my image upside down?
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- čas přidán 12. 09. 2024
- Another video in our series dealing with the basic principles of astronomy telescopes. This presentation explains why the image viewed in a telescope designed for astronomical viewing, as opposed to terrestrial, always presents the eye with an image that is not rectified (ie, looks upside down or flipped left to right).
Presented by Robert J Dalby FRAS
for The Astronomy and Nature Centre
Produced by DB Video Services for Astronomy and Nature TV
Thank you for another very helpful and informative video. I was panicking earlier, believing i had bought a broken reflector/Newtonian Telescope off Ebay because i tested it terrestrially and noticed the image was upside down, AND on an angle!! But after seeing your video, i'm very relieved! haha Thanks again, Wes. (new Amateur Astronomer)
Best explaination about "why it's upside down"!! Thank you!
After this video, I don't care about it :)
I don't know if anyone else has this issue, but I actually kind of have a problem with the typical mirror-reversed image of refractors (and SCTs and other Cassegrains) when used with a typical 90-degree mirror diagonal. Objects that I'm already familiar with just don't look right to me when flipped in one direction like that. Newtonians never bothered me in this way because images are simply rotated, and there is no one "true" or "official" way to orient them anyway--at least the objects look right. But flipping them on one axis by using an odd number of mirrors (one for refractors and three for Cassegrains, compared to two for Newtonians) just makes them look wrong, and even if this were the only way I had ever viewed any object, then I'm still kind of bothered by the fact that I know its image is flipped.
Now, this wouldn't happen if we looked straight through these types of telescope, but obviously that can literally be a pain in the neck, so we're pretty much forced to use an extra mirror that flips the image. This is one reason--and I realize it's a strange one--that I've generally stuck with Newtonians. I do own and occasionally use a refractor, but I skip the diagonal and look straight through it. :) I've tried using erecting prisms, but they only work OK on the widest true fields of view, and image quality breaks down quickly with the magnifications used in astronomy. Does anyone else have this weird issue? It's all psychological, of course, but it's still an annoyance. I'll take my images rotated, no problem whatsoever, but not flipped if I can avoid it.
Thank you so much I was losing my mind
The telescopes are made in Australia, that's why.
I guess the thing you said about newtonians stands up even more if you consider an equatorial mount also: the scope itself will be tilted at strange angles all the time, even more than on an alt-az mount.
This is a great video. I laughed out loud. Thank you for being a great teacher!
So I assumed if I purchased a reflector telescope it would be the right way up?? Is this the normal way people view the skies, upside down? Total newbie
Today I spent a couple of minutes in Photoshop, correcting a sky photograph to the more familiar view that I see through a Newtonian reflector. Of course inversion fundamentally involves two steps, flipping in the horizontal plane and flipping vertical plane. You can demonstrate this with a partially translucent sheet of paper with the letter J written on it. Then I discovered an embarrassing, forehead slapping point. Doing the two steps to a piece of paper is entirely equal to just rotating the page 180 deg. 180 deg rotation = horizontal flip + vertical flip. So, all I have to do is turn the book upside down (grin).
Cheers for that. I knew a bit why it turned the object upside down, but you have explain more and better, now I can explain this to my son. He ask me the exact same question the other day when I was showing him the moon through my new telescope 130P SkyWatcher 650mm focal. cheers.
Very well explained - thank-you.
Would be nice if you put a link to order those items
Ok, but how do I fix it without getting other eye piece?
You can’t
THANK YOU. I just got my first scope and it's vintage and I'm trying to assemble it.
Does the binoculars have the same in between lens? 🤔
I was very confused by your thumbnail!😂👍
Oh my dear almighty this guy is living in heaven on earth so many telescopes my eyes are watering 🤤
Amy image isn't upside down, it's left side right
Unless I missed something, this explained why we don't correct it, but not why it's like that in the first place.
lol you missed it
Super duper great video learn something new. Thank you 🙏
Thank you for your video!! I know this may be unrelated in lots of ways but I run a photo charity and i want to create a shed or dark tent with a pinhole in the wall and project the outside world inside the space as an installation. I want the image to be the right way up but need to know what prism / mirror etc i need to achieve this effect. Your help would be much appreciated thank you in advance and thank you for posting :)
Thank you so much for this explanation!!!
Why not point your telescope straight up so that it has less atmosphere to view the stars through?
Also there is no specific up or down direction on astronomical scale. And watch moon from southern hemisphere with naked eyes, its upside down of what we see in northern hemisphere. So there is no fundamental upside or downside for planetary viewing.
Thanks for the video =)
i knews it was gonna be upside down but it is also in a strange angle, thought the inner mirror got dislodged or something
do u have a weird left eye? or... sorry to ask . . .
Great video, very helpful, thank you.
Great video very informative, thank you.
So answer to the question is the image is meant to be upside down, is this right???
AND NOW I KNOW!! THANK YOU.
At 2:54 --- why is it mentioned that there are two lenses (quote "both lenses"). If there are two lenses in the front then the image should be correctly erected (no upside-down flipping). Or did I miss something?
Hi Toby, and thanks for posting. At the point referenced, Robert was just descibing the construction of the lens cell of the small refractor he was holding. All modern refracting telescopes have a compound primary objective composed of at least two lenses like this; and it has no relevence to correcting or rectifying the image. I hope this helps. A&NTV
@@RocketPlanet: Thank you for your reply and answer. I have this follow-up question then. If one lens flips the image upside-down, and if you say, that the lens cell has at least two lenses, then for the case of two lenses the image should be upside-down times two and hence we should have a correctly erect image at the eyepiece. But this is not the case as described in the video. Where is my thinking wrong?
Hi Toby, in the unique case of the objective lens, the two pieces of glass combine to form a single compound lens that functions as one lens not two. And thus has no bearing on correcting the image orientation at the eyepiece end of the telescope. KR RJDA&NTV
@@RocketPlanet: Cheers!! Thanks so much for the answer! ;-) Very helpful and appreciated.
shocking how aaaaaaaaalllllll the videos I saw on telescopes no one thought it would be smart to mention it. I'm annoyed, but I did only pay $40 for a powerseeker
Please i need help. My telescope is upside down, is this normal? And what should i do? My telescope is a refractor
I'm so annoyed I can't turn it propaly up with my mini scope
Very good now I know I thought I bought a lemon
So why use a multi element eye piece?
i have seen many reviews about meade etx 125, could you please tell me... my goal is to get the max terristial quality view from burj al arab, the tallest dubai building, such a telescope can offer me what if i look at celestial bodies, im trying to find pictures or videos to get an idea, i prefer a goto, what collection of eyepieces shall i buy , which meade model is my best bet, also that i have a nikon dslr and i plan to take pictures.. connector ?? softwares.. please help
if more lens means less light then how does it affect apo's with 3 or 4 lens?
When I bought my first newton telescope I thought they send me an Australian model! 😜👍
I don't mind the image in the main scope being inverted (I mostly do astrophotography anyway and the image *needs* to be inverted for the camera to get it right). But it annoys the heck out of me that the finder scopes that come with most telescopes also invert the image. When using the finder scope, terrestrial concepts such as up down left and right DO matter and it's hard to constantly having to invert it all in your head when looking for a particular star with the finder scope and naked eye. I can't seem to find a finder scope that produces a right image, nor any inverter attachment that will work with a finder scope. Anyone know if such thing can be obtained?
Hi Troels. A rectified or corrected finder is a standard item, and most of the main telescope manufacturers list them. For example, find any dealer that handles the complete SkyWatcher range and search their site for 'finder' - you'll see corrected models soon enough. They will typically feature a 90 degree prism to achieve the correction. Small straight through corrected finders are less common but they are available - the most common small one is a Meade/Bresser product and can be found on internet sites like www.astroboot.eu or www.astroboot.co.uk, depending on where you are. I hope this helps. KR RJD A&NTV
i have visionking D50 F350 , K9mm and K25mm 3x barlow, but i can't see anything. its only zoom in. but i cant see outside the planet earth. blurred! what should i do? everything is upside down lol
Great explanation, ru a teacher? Thanks for the video
Thank-you!
Tell that to ma'am gallano
Thanks nice Video,
i have meade 82 its good put latley the image is Upside down how can i solve this
Hi there, If you have the Meade Mini 82 (a small tabletop Newtonian reflector) there's not much you can do that would work well to rectify the image produced by that instrument. There are eyepieces that contain a set of prisms that will erect the image in principle, but it would still be at odd angles relative to the horizon because of the orientation of the focusor that cannot be altered on that model. But I'm not at all certain that the erecting eyepieces that are available would come to focus with that model anyway - you would need to consult with your supplier or Meade or take your scope to a dealer and try it. The Mini 82 is an astronomy telescope and is not designed for anthing else. I my opinion, pressing it into making terrestrial observations that will, at best, yield poor quality images and make the telescope difficult to use renders this exercise futile and is best avoided. If you want to press on with the idea then take a look at the Sky-Watcher 10mm Erecting eyepiece - but be warned, it may not come to focus. I hope this helps. KR RJD A&NTV
im gonna be fucked trying to find the moon even
Why cant anybody explain how a telescope works!
Why can't 'anybody' bother to go to the lending library and take out a Physics 101 primer, or assuming they are in Britain and the library is now a vegan cafe and wellness centre, log on to jolly old Amazon and buy the compendium soft-back set text for the same course? But it'll be easier just to wait for Sony to turn it into a game or Netflix to do a mini-series on the telescope. KR RJD A&NTV
oh I'm gonna reply because When my brain has time to think about something for a long period of time I can actually put things together but if I need to think I'm a fly I'm worth shit!
Its australian
Great video man thanks... now i just got'a buy that erecting prism for my girlfriend to solve that OTHER issue I have 😉😉
Pity we cant override our brains built in ability to flip the upside down Image that our eyes make. Obviously not while we are Driving/Riding a bike :)
Mine is the *1k* like 😁❤️😂
Dam... Great video, much appreciated...