Ill tell you in 5 seconds. The refresh rate of the camera coincides with the blades rotating, so each frame has the blade moving only a little, even thought its rotating much faster
@@AstroFazersPlaylist Exactly. The blades were rotating way too fast that the camera's shutter couldn't process instant images one by one, but instead, only parts of different succeeding instants into a single image.
Omg... Bit tricky but easily explained.. And I think now that's the same thing goes with the car's tyre(wheel disc). Am I right?? And that's happend with our eyes when like a racing car going to stop the metal disc in middle of tyre seems to be moving backward and it's give illusion that tyre is rotating in reverse direction.
BrainStuff - HowStuffWorks but with camera, it happened due to fps rate as u explained video is running of series of stills pic , but do our eyes also work on same concept?? Fps?? E. T. C.
Yep! Our vision also has a frame rate, basically -- something like 60 fps. That's because what we see is actually a series of signals from the photon receptors in our eyes being stitched together into complete images in our brains, over and over again. Nerdist has a good explanation: nerdist.com/your-brain-has-a-frame-rate-and-its-pretty-slow/
I tried it with my phone's camera, and yep, the room ended up looking bendy, with the walls slanting inwards as I waved the camera back and forth. Cool trick!
Baaasically, our eyes and brains have frame rates, too. When photons enter our eyes, each one can interact with a single neural cell there -- a rod or cone. Those cells then send an electrochemical signal to our brain, which stitches together all the signals from all the cells into a complete, moving image. But it's not a perfect, instantaneous system. Each cell sends a discrete signal each time a photon hits it. And there's a little bit of a gap between light hitting the cells in our eyes and our brains pasting together the information. So we see at about 60 frames per second. Which can create optical illusions like hubcaps spinning backwards in real life. /Lauren
BrainStuff - HowStuffWorks I thought you were a knowledgeable person...until you said we see life at 60 frames per second. Unsubbed for being more ignorant than my little brother.
BrainStuff - HowStuffWorks it's no where near as simple to just say we see life at 60 frames per second with the information you just provided. Please stop spreading false information.
If the rotor is spinning the same speed as 60fps, it will look like its lagging irl. Joke: "Umm Somethings wrong with you..." "What? What happened?" "Wait a minute, WHY IS'NT MY ROTOR SPINNING???" "Because i didn't start the engine." "But why im flying???"
Great video, but it's probably more accurate to say that the blades are moving at a much higher number of times per second that are evenly divisible by the frame rate. So, if the frame rate is 30, the RPM could be something like 300 or 330 RPM. ... or, even a number divisible by 1/6 since there are 6 blades on the heli, and the video could be "swapping out" blades to still give us that illusion. Just a guess.
that explains a lot. however I see the same effects with my own eyes and not through a camera. one example is a car's rims. when the wheels are spinning really fast the rims sometimes appear spin backwards. I see this effect all the time with my own eyes and not through a camera. how do u explain that?
ilovesudan Same thing.. your brain has a "frame rate" as well, if you will. Not as straightforward as a camera, but you can only process so many images at once.
rullo69 "no, eye-brain image processing have no frame rate" Back to school for you! Neurons can only fire so many times per second, and for some people it's so slow that the world appears to move in stop motion.
In my electronic engineering classes, we learned about "aliasing". In simple terms, the sample rate is too low (the frame rate vs. rotational speed of rotors). It is a nice way to visualize the artifacting that happens when the Nyquist theorem is not satisfied, whether we are shooting video or recording digital audio ; )
Nice explanation. Although another one exists. It's not necessary that the same blede to be in the same place each frame. As the blades look similar, any other blade can be in its place to create the effect.
so i guess, for your example with the hind, this formula would be correct: "rpm= n/6*24*60" n being a specific natural number, divided by 6 because of the 6 blades, which any one of those can be at this position at the moment of taking the picture, multiplied by the framerate converted into minutes.
Lerkero shutter speed won't match with rotation.. that would be frames per second. The shutter speed will dictate how much motion blur that rotating object has. Faster shutter speed means less motion blur, more visible rolling shutter effect Slower shutter speed means the opposite
Lerkero: If you have a strobelight put it in front of a fan that is on then adjust the strobe light flash speed until the fan blades appear to stop moving.
As a kid I used to watch plane propellers on TV start one direction and then look like they reverse. That was never explained. I've seen repair men use a strobe light on spinning shafts to make them look like they are setting still.
24fps is the cinema standard and show a motion blur similar to what we see naturally. Unless it's for a short sequence (Saving Private Ryan), high frame rates haven proven distracting and enough to 'pull you out' of the movie. Even if I'm recording 120fps for slomo, I still render to 24fps.
Helicopters rotors spin 4 to 500 rotations per minute, plus they don't stay exactly the same speed during turns and due to the wind and different things. So that would mean that the shutter speed would have to charge with the rotor speed, not even knowing what it is... I believe there's a little bit more to these hovering helicopters than frame rate and shutter speed.
Question. Would this be a way to confirm our estimate for the speed of light? As the helicopter moved further way, IF the rotor speed remained the same, and IF the photo-capture speed remained the same, then the reason the blades start to "appear to move" gradually faster might be: because it's taking gradually longer for the light bouncing off of the helicopter to reach the camera, as it moves further away, and thus offsets when/where the propellers "appear" in each rotation?
Some film cameras also have/had something analog to the rolling exposure, causing pictures of racing cars seem to have tilted, "italicized" wheels, funnily making them look faster. Maybe that was even where cartoonists got this kind of caricature of movement they often use for this kind of illustration.
Why this channel does not have five million subs by now is surprising. This shows, today's young people would rather go on RUclips to watch twerk video than learn all these cool stuff here. smdh
Maybe it's because some ugly woman talking with her hands is not what 5 million people are looking for. Despite the content of the video being entertaining, the manner in which it is presented is awful. I couldn't watch past the first 10 seconds once she appeared on the screen.
The helicopter rotors in your animations rotate in the wrong direction. The tapering part (the blade root cutout) is at the _trailing_ edge of the blade; thus, as depicted, the blades should be rotating counterclockwise. Other than that, it’s a solid, if somewhat longwinded, explanation.
Okay, thanks. My friend and I were at a World War II airshow and we were taking video of planes taking off, but their rotors appeared to move really slow or backwards like you said.
Then again. I should have typed this is a great video, because it is. Not nice or mean, just straight up raw facts. Many knew about this already, many, like me, knew some of the reasons why, like I knew about frame rate because of the videogame culture, but didn't know exactly about shutter speed or the bit about digital cameras, and many people didn't know anything about this at all. Honest & factual videos like this, will make the world a better place. Even out of the way, scientific things like this, that has information irrelevant to most people. Learning about random things like this, may inspire people to create or improve something. I think this is the best way to learn about mostly irrelevant things, by choice. Not making mostly irrelevant information, mandatory to learn. Schools trying to teach ancient history & algebra, instead of what really matters, like basic first aid, credit, money, and road use.
So that spinning backwards thing is because of the lower frame rate compared to the frequency of rotation of the helicopter blades, or something like that right? That thing happens with our eyes too. For example when you are on the road and try to fix your eyes on a car's wheel next beside you. The wheel, for some moments starts to spin backwards as well. Sooo, does that mean our eyes have a frame rate? 🤔 Hahaha
Optical illusion. The eye and brain also receive information about moving objects as a series of images -- a series of photons hits the neural cells in your eyes, and those cells send an individual packet of data about each photon to the brain to be stitched together into your vision. We see at about 60 frames per second.
does the helicopter blade looks freezed when we see it through our eyes too?? coz we see that the tyres os bike spinning back while its really moving forward
Not bad, pretty close. Actually it revolves around the shutter speed per second and the frames per second. Both must come into play for the blades to appear motionless. Frames and shutter speeds dont always match in cameras. Say the frames per sec in ur camera are 32 and shutter speed is 33 and the helo blades are rotating at 32 rotations per sec. The blades will appear slightly blurry and look as if their in supper slow motion rotating clockwise. Now if the blades and camera frames were at 33 per sec and ur shutter at 32 the helo blades would look. Slightly blurry in supper slow motion going counterclockwise.. Hope this helped. PS- regular helo & not a gov secret flight..
They can "match" in many combinations. If the rotor has 6 blades, they can match at 1:1, 2:1, 3:1, 4:1 etc. but also 1/6:1, 1/3:1, 1/2:1, 2/3:1, and also 1&1/6:1, 1&1/3:1, 1&1/2:1, and 2&1/6:1, 3&1/6:1, etc. etc. etc.so as the helicopter blades change speeds they are CERTAINLY going to pass through some of these combinations at some point. It is not like winning the lottery at all.
Ill tell you in 5 seconds. The refresh rate of the camera coincides with the blades rotating, so each frame has the blade moving only a little, even thought its rotating much faster
That explains one type of visual distortion, yep!
PapaKay chemtrails are real * is what I got from this
RealTimeModz Good bait.
remember it the Black Hole is a greatest
and some people even need that explanation (not to mention 4 min video)...
3:20 most explicative animation ever
brilliant indeed
Best explanation I ever heard. Camera is working too slow to capture picture instantly.
@@AstroFazersPlaylist Exactly. The blades were rotating way too fast that the camera's shutter couldn't process instant images one by one, but instead, only parts of different succeeding instants into a single image.
I am the only one who thinks those clips of the helicopters are hilarious?
Dmack18 nope :P
No
Dmack18 yes you fucking weirdo
no, I agree
Yes. You are the Only one.
And everyone thought our world was glitching like a simulation
Omg... Bit tricky but easily explained.. And I think now that's the same thing goes with the car's tyre(wheel disc).
Am I right??
And that's happend with our eyes when like a racing car going to stop the metal disc in middle of tyre seems to be moving backward and it's give illusion that tyre is rotating in reverse direction.
Exactly!
BrainStuff - HowStuffWorks but with camera, it happened due to fps rate as u explained video is running of series of stills pic , but do our eyes also work on same concept?? Fps?? E. T. C.
Yep! Our vision also has a frame rate, basically -- something like 60 fps. That's because what we see is actually a series of signals from the photon receptors in our eyes being stitched together into complete images in our brains, over and over again. Nerdist has a good explanation: nerdist.com/your-brain-has-a-frame-rate-and-its-pretty-slow/
BrainStuff - HowStuffWorks omg..why I subscribed u so late
. 😱😱thanks a lot for this information.. 😊
BrainStuff - HowStuffWorks nd now I know the secret of trick shown in "now u see me 2"😜
Her: come over
Him: I can't my helicopter is out of fuel
Her: my parents aren't home
Him:
🤣
I've noticed that effect in cars wheels as well! Very interesting video, thank you!
I tried it with my phone's camera, and yep, the room ended up looking bendy, with the walls slanting inwards as I waved the camera back and forth. Cool trick!
What about car wheels with no camera just my eyes?????
you won't see rolling shutter with your own eyes.
Baaasically, our eyes and brains have frame rates, too. When photons enter our eyes, each one can interact with a single neural cell there -- a rod or cone. Those cells then send an electrochemical signal to our brain, which stitches together all the signals from all the cells into a complete, moving image. But it's not a perfect, instantaneous system. Each cell sends a discrete signal each time a photon hits it. And there's a little bit of a gap between light hitting the cells in our eyes and our brains pasting together the information. So we see at about 60 frames per second. Which can create optical illusions like hubcaps spinning backwards in real life. /Lauren
BrainStuff - HowStuffWorks I thought you were a knowledgeable person...until you said we see life at 60 frames per second. Unsubbed for being more ignorant than my little brother.
BrainStuff - HowStuffWorks it's no where near as simple to just say we see life at 60 frames per second with the information you just provided. Please stop spreading false information.
60 fps per second for real life? Thats Bull. We can see difference between 60 and 144 fps.
Seizure warning would be nice with them flashes...
TRIGGERED!!
Rory Rafferty did you seize? 😂😂😂
Pretty sure the flashes were far too slow to trigger a seizure.
Edit: Holy shit, I replied to a year old comment. Sorry for pinging. >_>
Bladefury nothing is old. Even the oldest youtube vid ever is still getting some comments this year
@@sheepherd2210 the oldest RUclips video is captured by bots, so you will find a new comment every second. Also I am replying to a 2 year old comment
3:29
The car was like: bro that was close
I've being wanting to know this for such a long time, thansk
*thanks
If the rotor is spinning the same speed as 60fps, it will look like its lagging irl.
Joke:
"Umm Somethings wrong with you..."
"What? What happened?"
"Wait a minute, WHY IS'NT MY ROTOR SPINNING???"
"Because i didn't start the engine."
"But why im flying???"
Great video, but it's probably more accurate to say that the blades are moving at a much higher number of times per second that are evenly divisible by the frame rate. So, if the frame rate is 30, the RPM could be something like 300 or 330 RPM. ... or, even a number divisible by 1/6 since there are 6 blades on the heli, and the video could be "swapping out" blades to still give us that illusion. Just a guess.
that explains a lot. however I see the same effects with my own eyes and not through a camera. one example is a car's rims. when the wheels are spinning really fast the rims sometimes appear spin backwards. I see this effect all the time with my own eyes and not through a camera. how do u explain that?
ilovesudan Same thing.. your brain has a "frame rate" as well, if you will. Not as straightforward as a camera, but you can only process so many images at once.
AEguy Productions no, eye-brain image processing have no frame rate, I think it is possible due to a road light flickering exposition
road lights flicker with 100-120 Hz, depending on grid frequency
ilovesudan That happens with everyones eyes. You can easily find videos explaining this.
rullo69 "no, eye-brain image processing have no frame rate"
Back to school for you! Neurons can only fire so many times per second, and for some people it's so slow that the world appears to move in stop motion.
@2:03 no need for a full revolution. 1/6 of a revolution and the effect already works, since these blades have hexagonal symmetry.
True.
This is actually great for beginner photographers 👌
^___^ Thank you!
Excellent explanation
at last understood what does rolling shuttee mean. thank you!
In my electronic engineering classes, we learned about "aliasing". In simple terms, the sample rate is too low (the frame rate vs. rotational speed of rotors). It is a nice way to visualize the artifacting that happens when the Nyquist theorem is not satisfied, whether we are shooting video or recording digital audio ; )
I am so glad I finally understand it coz I've always wanted to know that.
Nice explanation.
Although another one exists. It's not necessary that the same blede to be in the same place each frame. As the blades look similar, any other blade can be in its place to create the effect.
so i guess, for your example with the hind, this formula would be correct: "rpm= n/6*24*60"
n being a specific natural number, divided by 6 because of the 6 blades, which any one of those can be at this position at the moment of taking the picture, multiplied by the framerate converted into minutes.
Awesome explanation and video. I didn't know about shutter speed matching with rotation
Lerkero shutter speed won't match with rotation.. that would be frames per second. The shutter speed will dictate how much motion blur that rotating object has.
Faster shutter speed means less motion blur, more visible rolling shutter effect
Slower shutter speed means the opposite
Lerkero: If you have a strobelight put it in front of a fan that is on then adjust the strobe light flash speed until the fan blades appear to stop moving.
Thank you for posting this video that taught me a lot about fast objects in film
As a kid I used to watch plane propellers on TV start one direction and then look like they reverse. That was never explained. I've seen repair men use a strobe light on spinning shafts to make them look like they are setting still.
This is a good explanation of the interferometric effect.
Great video as usual. Great to see Lauren is back !
Thanks for sharing 😊
Great video and really well explained.
Excellent explanation.
honestly if you're still shooting at 24fps get a better camera
It's the cinematic authentic Ubisoft experience.
If you really know why 24fps is widely used and considered common for standard shoots, you wouldn't have said that.
24fps is the cinema standard and show a motion blur similar to what we see naturally. Unless it's for a short sequence (Saving Private Ryan), high frame rates haven proven distracting and enough to 'pull you out' of the movie. Even if I'm recording 120fps for slomo, I still render to 24fps.
Cinema cameras over $40, 000 will shoot video at 24fps because that's the standard for cinema
***** actually it sees at more than 24 fps. Why do you think 24 fps has blurs on things you see moving clearly
In short, shutter speed determines how sharp/blurry the images are.
Frame rates determine the apparent motion of a rotating object.
Best explanation of the concept.
Great stuff!
HEY AWESOME WORK GUYS LOVE UR CONTENT UPLOAD MORE VIDS PER MONTH
Thanks! We've been busy with other projects lately, but we hope to start publishing more frequently again soon. ^___^
thanks for replying brainstuff i am honored looking forward for more amazing videos :-) !!!
Thanks for the explanation.
Helicopters rotors spin 4 to 500 rotations per minute, plus they don't stay exactly the same speed during turns and due to the wind and different things. So that would mean that the shutter speed would have to charge with the rotor speed, not even knowing what it is... I believe there's a little bit more to these hovering helicopters than frame rate and shutter speed.
BTW, in that graphic of the rotor blades spinning at different frame rates, the blades are moving in the wrong direction.
Question.
Would this be a way to confirm our estimate for the speed of light?
As the helicopter moved further way,
IF the rotor speed remained the same,
and
IF the photo-capture speed remained the same,
then the reason the blades start to "appear to move" gradually faster might be:
because it's taking gradually longer for the light bouncing off of the helicopter to reach the camera, as it moves further away, and thus offsets when/where the propellers "appear" in each rotation?
Excellent presentation! Thank you.
Very good explanation
I found out just like the helicopter blades 🚁, I noticed that ceiling fan blades can also look weird on video too.
This video give education than other... Thanks
Perfectly explained, thanks
LOVE YOUR VIDEOS GUYS AWESOME WORK !!!
Some film cameras also have/had something analog to the rolling exposure, causing pictures of racing cars seem to have tilted, "italicized" wheels, funnily making them look faster. Maybe that was even where cartoonists got this kind of caricature of movement they often use for this kind of illustration.
In summary, my name is Giovanni Giorgio, but everybody calls me Giorgio
In summary, my name is Giovanni Giorgio, but everybody calls me Giorgio
Why this channel does not have five million subs by now is surprising. This shows, today's young people would rather go on RUclips to watch twerk video than learn all these cool stuff here. smdh
Maybe it's because some ugly woman talking with her hands is not what 5 million people are looking for. Despite the content of the video being entertaining, the manner in which it is presented is awful. I couldn't watch past the first 10 seconds once she appeared on the screen.
Mark Malasics yeah true I would rather to watch life noggin than this
If the appearance of the presenter is what is so important, then you're what is wrong with everything in society today.
The helicopter rotors in your animations rotate in the wrong direction. The tapering part (the blade root cutout) is at the _trailing_ edge of the blade; thus, as depicted, the blades should be rotating counterclockwise. Other than that, it’s a solid, if somewhat longwinded, explanation.
NOOO YOU CANT FLY WITHOUT THE BLADES!
helicopter: haha we fly go brrrrr
Okay, thanks. My friend and I were at a World War II airshow and we were taking video of planes taking off, but their rotors appeared to move really slow or backwards like you said.
Could anyone tell me about the editing behind this video? Program used? Camera and mic? Animations? Thank you!
Very informative
Thank you. This is a nice video.
Then again. I should have typed this is a great video, because it is. Not nice or mean, just straight up raw facts.
Many knew about this already, many, like me, knew some of the reasons why, like I knew about frame rate because of the videogame culture, but didn't know exactly about shutter speed or the bit about digital cameras, and many people didn't know anything about this at all.
Honest & factual videos like this, will make the world a better place. Even out of the way, scientific things like this, that has information irrelevant to most people. Learning about random things like this, may inspire people to create or improve something. I think this is the best way to learn about mostly irrelevant things, by choice. Not making mostly irrelevant information, mandatory to learn. Schools trying to teach ancient history & algebra, instead of what really matters, like basic first aid, credit, money, and road use.
^____^ Thank you so much! This made our day. We're just doing our part. /Lauren
hey,i am getting confused more. is it like that higher the frame rate is directly proportional to shutter speed? thank you.
Thank you for clearing ❤️
Do you remember old western movies? Car wheels going backwards
Long answer
Short answer:its on sync with the frame rate of the camera
I wonder if uf the same Idea can be use to look at the electron path though the slits during a double slit experiment
thanks 4 the information
You rotate lens on your phone? Do you use a toothpick or a nail to do that?
+Spare me from my pain It's near the end of the video.
Now I understand why the videos I watch have a weird effect propellers it's the shutter effect👍👍👍😁🙂
2:38 That's forwards rotation, not backwards, FYI.
In that footage, why is the tail blade captured rotating but the big blades are still?
Nice video, thanks a lot ! 👍
Same thing happens to my wiper blades through my dash cam. Now i get it! Thanks! 😄
Reminded of Vsauce
So that spinning backwards thing is because of the lower frame rate compared to the frequency of rotation of the helicopter blades, or something like that right?
That thing happens with our eyes too. For example when you are on the road and try to fix your eyes on a car's wheel next beside you. The wheel, for some moments starts to spin backwards as well.
Sooo, does that mean our eyes have a frame rate? 🤔 Hahaha
Thanks. But those effects can be observed even without cameras. Now, how is that?
Optical illusion. The eye and brain also receive information about moving objects as a series of images -- a series of photons hits the neural cells in your eyes, and those cells send an individual packet of data about each photon to the brain to be stitched together into your vision. We see at about 60 frames per second.
'appreciate it. Thanks :-)
That didnt help a lot. What about a video of "Why Helicopter Blades Can Look Strange on the eye" explaining this better? It sounds like a whole topic.
That was cool, thanks!
does the helicopter blade looks freezed when we see it through our eyes too?? coz we see that the tyres os bike spinning back while its really moving forward
Cool, a Vulcan. Hello!
What is the perfect fps for heli?
Shout out to her eyebrows, the real MVP; holding up her bangs all by themselves.
Patch notes:
-fixed floating helicopter
I'll never watch a western the same way again . . . . Well explained !! Thx much
3:23 so this is why motion blur exists too?
i didnt know cameras could do such a thing
One of life's questions answered. Thanks!
I noticed this effect when I was staring into my computer's exhaust fans the other day, it weirded me out.
When we say frames per second we mean pictures per second. So if you draw a lot of pictures you can actually make a film. But you need millions
I thought in video, shutter speed is represented as an angle. The fraction is only for still images (yes I know video is made up of still images)
In vintage video cameras, the spinning blades of a helicopter looks like just it was as it was in reality.
Not bad, pretty close. Actually it revolves around the shutter speed per second and the frames per second. Both must come into play for the blades to appear motionless. Frames and shutter speeds dont always match in cameras. Say the frames per sec in ur camera are 32 and shutter speed is 33 and the helo blades are rotating at 32 rotations per sec. The blades will appear slightly blurry and look as if their in supper slow motion rotating clockwise. Now if the blades and camera frames were at 33 per sec and ur shutter at 32 the helo blades would look. Slightly blurry in supper slow motion going counterclockwise.. Hope this helped. PS- regular helo & not a gov secret flight..
0:26 LMAO
WARNING! - This video can cause epileptic fit.
There should be a Strobe light warning on title or description it can cause seizures other than that the video was very informative
We can film helicopters moving through the air at 300 mph but can't get a good resolution of a UFO I wonder why?
LoL
Try looking at your hand shaking it as fast as you can and blinking your eyes constantly and rapidly !!!!
You'll definitely understand now ...
So well explained ! Thank you
thank you for the science
What about looking at a fan?
What if shutter speeds and FPS is lower than blades speed, pls reply
I have 1 awesome picture of a helicopter, with the blades bent very far back, but still no separate blade in the middle of the air.
I can answer the entire video in one sentence
The camera shutter speed is synced with the speed
And just how close would the frequency or frame rate have to match? You have better odds at the lottery me thinks. Oh we have one that Can SEE....
They can "match" in many combinations. If the rotor has 6 blades, they can match at 1:1, 2:1, 3:1, 4:1 etc. but also 1/6:1, 1/3:1, 1/2:1, 2/3:1, and also 1&1/6:1, 1&1/3:1, 1&1/2:1, and 2&1/6:1, 3&1/6:1, etc. etc. etc.so as the helicopter blades change speeds they are CERTAINLY going to pass through some of these combinations at some point. It is not like winning the lottery at all.
It's quite funny that our eyes can trick us in similar ways
that was amazing..
I thought I was dreaming. So this explains what my supposed dreams were
That O is a bulls eye