Copter flies without main propellers spinning?

[Aaron LeClair]

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Many comments say this is an illusion. I haven't seen anything quite like it before.

 

[Aaron LeClair]

Another similar vid.

 

[Brian Now]

that's great video!

I don't know how it is done. I have never seen blades appear like that on camera ever in my life. What I have seen is blades appear very slow moving but with plenty of blur. I have never seen anything exactly like this before. It is a really cool sight to see.

 

[Rick Deckard]

That has to be something to do with camera shutter-speed - sometimes the spokes on alloy car wheels look stationary when filmed rotating at certain speeds. Each new frame of film/video just happens to be synchronized in such a way that it always captures the blades in exactly the same position - everyone is aware of that effect, right?

Besides, you can hear the noise of the blades 'whacking' the air...

It's a cool effect, but I expect it's made easier to pull-off with digital equipment offering variable capture frame-rates.

 

[Brian Now]

That has to be something to do with camera shutter-speed - sometimes the spokes on alloy car wheels look stationary when filmed rotating at certain speeds. Each new frame of film/video just happens to be synchronized in such a way that it always captures the blades in exactly the same position - everyone is aware of that effect, right?

Besides, you can hear the noise of the blades 'whacking' the air...

It's a cool effect, but I expect it's made easier to pull-off with digital equipment offering variable capture frame-rates.

I am basically aware of how cameras can make things look, but you should still see some blur.

But let's say it was just the camera that made the blades appear stationary. How does that explain the shadows of single blades on the body of the helicopter in the first video? I wonder if some CGI was involved.

If this is untampered video then we should be able to find other unrelated footage out there with the same effect.

 

[Rick Deckard]

How does that explain the shadows of single blades on the body of the helicopter in the first video? I wonder if some CGI was involved.

The shadows and reflections move with the blades - if the blades are made to appear stationary because of the 'camera trick' then it follows that the shadows and reflections will also appear stationary.

In normal vision, the shadows and reflections appear blurred because the human eye and brain are unable to perceive them individually.

 

[Brian Now]

The shadows and reflections move with the blades - if the blades are made to appear stationary because of the 'camera trick' then it follows that the shadows and reflections will also appear stationary.

In normal vision, the shadows and reflections appear blurred because the human eye and brain are unable to perceive them individually.

I meant blurred on camera, already know about the human eye .

But I am not yet convinced it follows that the effect you are talking about would go for the shadows too.

 

[Rick Deckard]

But I am not yet convinced it follows that the effect you are talking about would go for the shadows too.

Erm, why? In reality the shadows are fairly 'sharp' - but they're moving so fast the human eye can't discern the 'edges'.

If you took a single high-speed photo, you would see the individually cast shadows.

Actually, you could take a normal photo when the blades really are stationary - same difference.

 

[CapnG]

There's no mystery here, it's a simple matter of frame rate. 24 frames a second typically, 48 for panavision film, 30 for video, 60 for digital video. Basic film school stuff.

 

[turblom79]

I hate to say it, but I don't think this is an illusion at all. It looks to me like a model on a string! The way the helicopter flies looks like it is swinging on a string, especially at the end when it reaches one end of a swing and starts going back in the opposite direction. The sound effects could have easily been added on later.

 

[Aaron LeClair]

I hate to say it, but I don't think this is an illusion at all. It looks to me like a model on a string! The way the helicopter flies looks like it is swinging on a string, especially at the end when it reaches one end of a swing and starts going back in the opposite direction. The sound effects could have easily been added on later.

What about the second video?

 

[BrandonD]

I hate to say it, but I don't think this is an illusion at all. It looks to me like a model on a string! The way the helicopter flies looks like it is swinging on a string, especially at the end when it reaches one end of a swing and starts going back in the opposite direction. The sound effects could have easily been added on later.

For what it's worth, this is not a model because I saw a clip where the copter is flying in some sort of airshow in front of a bunch of witnesses.

But I did get some information recently which might be of some help in solving this mystery. A friend at work told me that he had been in a few helicopters in the military. As he was talking to me he asked, "Do you know how a helicopter rises and lowers in altitude?" I said the intuitive answer, which was that the pilot made the propellers rotate faster or slower. He said, "No, the pilot generally has the propellers rotating at a set RPM. Actually the blades are slightly tilted up and down in order to rise and lower."

What occurred to me is that, because the copter's blades are rotating at a set RPM, a camera could conceivably set their shutter speed (intentionally or accidentally) to the same speed and it would appear that the blades are stationary.

In theory, at least.

 

[CapnG]

What occurred to me is that, because the copter's blades are rotating at a set RPM, a camera could conceivably set their shutter speed (intentionally or accidentally) to the same speed and it would appear that the blades are stationary.

I'm pretty sure I just said that... That is exactly waht's happening. You can see this in car commercials (well, ones that use actual cars anyway). The hubcaps will often appear to spin slower, backwards or not at all.

Anyone who thinks this is a hoax, a model, or CGI, STOP! This is a simple trick of photography AND NOTHING ELSE.

 

[Rick Deckard]

He said, "No, the pilot generally has the propellers rotating at a set RPM. Actually the blades are slightly tilted up and down in order to rise and lower."

Yep - it's call the 'angle of attack'.

What occurred to me is that, because the copter's blades are rotating at a set RPM, a camera could conceivably set their shutter speed (intentionally or accidentally) to the same speed and it would appear that the blades are stationary.

Exactly.