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?
Definitely real. It is related to both really. The frame rate is synched with the rotors, an effect which is exaggerated by the high shutter speed that freezes the blades in place each time a frame is captured.
It is possible with shutter speed.
Next time it rains go out and start filming it at 1/50 and shift it up to 1/4000. You’ll se a dramatic change and basically the same thing happens here.
It is the FR and shutter speed, but mostly the former. As others have said you need a shutter speed high enough that a single shot would appear to freeze the rotors. More importantly the frame rate needs to be an even fraction of the rpm (not a multiple). If the frame rate was exactly 1/10 the rpm then it would grab a quick shot on every 10(h rotation.
The slow rotation of the main blade is proof it’s real, prettty much, or a super high quality fake. Put it this way, doing it for real would be cheaper and easier than faking it this well.
I think the shutter speed just have to be fast enough to freeze the blades and then it is just about the frame rate…e.g. shoot at 120fps and keep only the frames with the blade at the same position…imho 🙂
btw. engine speed remains (almost) constant in helicopter flight; vertical thrust is adjusted with collective pitch.
It’s the shutter speed.
Why?