Helicopter Incredibly Rises "Without Moving" Its Rotor
If you have ever watched a video of helicopters, you will have s surely observed that their blades are moving strangely like sometimes it looks slow, sometimes it looks jittery. Even you may have noticed sometimes that it is not moving at all and it’s different every time. Why is it so? We will answer it shortly.
This is the moment when a helicopter surprisingly starts to fly above the helipad despite its blades are completely in static condition. The video has been confusing viewers who can’t understand this strange phenomenon that how the helicopter is operating without it's motor running. But the reality is completely different.
The video was uploaded to a social media website by a person named Chris Chris, who captioned the video as ‘the helicopter looks like it is moving magically.’
In the video, the blades of the helicopter at some points can be seen moving slowly but, not that much fast as someone can expect for a helicopter while taking off.
Even it starts to fly in the forward direction, the blades can be still seen stopped before the video ends.
But, as the man who posted the footage indicates a trick of the camera, which is responsible for the helicopter’s strange behavior, writing ‘the shutter speed of the camera match’s aircraft’s rotor.’
The optical illusion is failed as compared to the camera’s frame rate and shutter speed, which contorts the appearance of turning things when they synchronize. The footage shows how the blades of the helicopter appearing to move slowly as it takes off but not as fast as it would need to make the aircraft fly. Shutter speed means the total time a camera spends to collect light every time it takes a video or a picture. The more time a camera spends gathering light, the more its image will appear to be motion-blur. The video states ‘suppose you are shooting a 25fps video of an aircraft rotor that turns one full spin each second. In the footage, each spin will thus be broken into 25 frames. You will see the normal rotation of the blades, just moving one-25th of its full rotation every time.
But one more phenomenon is: if the blades rotate exactly 25 times every second, and you are still filming at 25 fps, each full rotation will be considered as just one frame. The blades of the helicopter will arrive back to their initial position each time the camera catches a specific frame, so they will look like they are still in a static position. So the fact is, the blades are moving normally but you can’t see it due to the fact discussed above.