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?
Its real and its frame speed.
Nice hedge!
It is both, shutter speed to freeze the motion, frame rate to sync the blades.
The speed of the rotor is constant for the most part. Go out and get a toy helicopter, the cheap ones vary the speed of the blades where the more expensive ones change the pitch of the blades. Which one is easier to control? The one where the pitch of the blades are changed.
I believe there used to be an example of a similar situation at the Chicago Museum of Science and Industry.
The exhibit demonstrated why circus wagon wheels would appear still at certain speeds (ever watch a western and notice the wagon wheels appear to move at different speeds compaired to the wagon?), The exhibit had a strobe that the viewer could adjust the strobe frequency flashing on a spinning wheel. By changing the strobe rate, you could make the wheel appear to spin, freeze, and even go in reverse.
I am going to say this is shutter speed dependent as a camera shutter would equal the strobe of the light from the exhibit.
Looks real. Again I don’t know why someone would fake it. Also the rotors do move a little and the pitch changes. The tail rotor is moving and if you were going to fake it wouldn’t you just fake that as well?
Why someone would spend the time creating a fake of this bewilders me about as much as why I spent 20 minutes geeking out about it’s validity.