This article is definitely in the realms of really really specialist photography! However some of you may find it interesting and we here at ClickASnap love tech 🙂
So a couple of years ago this video was released by MIT:
This is a video taken by a incredibly specialist camera taking 1 trillion frames per second. This is fast enough to actually photograph the movement of light through the atmosphere as shown by the short video above.
The speed of light is roughly 186,000 miles per second, and there is no way a camera can operate faster than the speed of light so how can a camera photograph the movement of light?
The camera that does this was created in Japan and is called STAMP (Sequentially timed all-optical mapping photography) With such a camera, and sub trillionth of a second exposure times a normal flash just won’t do the job! So a Titanium Sapphire laser is used that emits pulses at regular intervals of ~13 nanoseconds. These pulses illuminate the scene to be photographed and then trigger a picosecond accurate streak tube which captures the light. A streak camera has a fairly reasonable horizontal view but incredibly narrow in the vertical dimension (the equivalent to 1 scan line) Every time a recording is made it is effectively a 1D movie. In this movie 480 frames are recorded with an exposure time of 1.71 picosecond. A system of computer controlled, incredibly accurate mirrors are used to effectively scan the camera across the object to be recorded. The images are then all added together and the finished movie is ready to go.
I remember seeing this on YouTube a couple of months back. I still struggled with the idea that a camera can capture the photons of light as they travel, especially has light is the only constant and nothing can, as far as we know, travel faster than light, which the camera would of had to had done to capture such images. However, now you have explained it, it makes much more sense. Thank you 🙂
More then welcome, it is an amazing feat of photography