This incredible slow motion video shows what really happens when you snap a picture

The Slow Mo Guys are at it again, and this time they've used their slow motion cameras to record the lightning-fast process behind snapping a picture.

The video, filmed using a Phantom Flex at 10,000 frames per second, does a great job showing what happens between the time you press the camera button and when the shutter opens and closes.

This particular example shows how a "rolling shutter" works on a typical DSLR camera that's had the lens removed.

A mirror placed at a 45-degree angle allows you to gaze through the viewfinder and see exactly what the lens sees, but that mirror gets in the way of the sensor. So in order to clear the path from the light to the sensor, the mirror flips upward and out of the way, while the mechanical shutter rolls away to reveal the sensor. The sensor captures an image, and the shutter rolls in front of it again and the mirror snaps back into place.

All this happens in less than a second, all you hear is the sound of all the parts moving in tandem.

It's a fascinating process, and the video below has more examples of what happens when you adjust the exposure of a photo, which can cause the shutter to expose the sensor for longer or shorter amounts of time.

No wonder DSLR cameras cost so much.