If you’re a regular reader, you know that I am on-the-record with a deep belief that photography and filmmaking are not all about speeds and feeds or how big your megapixels are compared to mine. Nonetheless, I do have a healthy respect for the technical side of the craft — and for those who dive in deep.
Like the guy who made this video, for example.
This optical illusion is “purportedly” made possible by synching the camera shutter speed with the rotation of the helicopter’s blades, giving the latter the appearance of “staticity.” Some cry hoax. Others say it’s real. Those who believe it is real have engaged in lengthy debate about how it was achieved. The two sides’ arguments break down like this:
SS: “As the title of the video suggests, the filmmaker synched his shutter speed with the rotation of the helicopter blades to make it appear as it does.”
FR: “This is a matter of frame rate, not shutter speed. The frame rate has to be synched such that with each frame exposure the blades are in the exact same position.”
So here’s the quiz – what’s your take? Real or fake? Shutter speed or frame rate?
+1 to the last comment 😉 they should also tether the space shuttle and say it´s an OVNI lol
Or maybe it is hooked up to another chopper above. That would explain why the camera never goes wide angled.
This phenomenon even has a name: temporal aliasing. it´s basically the same thing as using stroboscopic lights to “freeze” movement and has to do with both shutter speed and frame rate. shutter speed as was said before accounts for a reduced motion blur and frame rate is what syncs the motion in place. if your temporal sampling ( frame rate) is higher, the blades would look moving in one direction, if it´s lower it would look as moving the other direction. same thing happens when you look at a car accelerating, at a time the wheels seem to move to one direction, let the car move faster and you literally see how the wheel seem to reverse (which is of course an optical illusion called again: aliasing)
+1 for aliasing. That’s exactly what’s happening, and it’s because the sampling (frame) rate is too low to accurately reproduce the signal (position of blades).
1.) You mean you can’t see the skyhooks? You know, what holds the helicopters and airplanes up in the air? 😉
2.) The semantics of it all is that the method to sync is probably framerate. This would put me in the framerate crowd, but I honestly think it’s just semantics.
As others have mentioned, the blades appear to be slowly moving, the back rotor is moving slowly, the pitch of the helicopter blades changes which results in speed and direction. You do this with an extremely high framerate.
3.) Nice model helicopter. 😉
I think it’s real..