MIT's New Camera Can Take 1 Trillion Frames Per Second 197
First time accepted submitter probain writes "MIT has made a camera that can take trillion frames per second! With this high speed capability, they can actually see the movement of photons of light across a scene or object. This is just mind-boggling." ExtremeTech has a nice video of the system, too. What would you like to see slowed down to such a degree?
Re:i'd be dead before that water balloon pops (Score:2, Informative)
The problem is that photons ARE light, and the camera CONSUMES them by seeing them.
You can never see the same photon twice. The act of seeing absorbs it.
Re:Bullshit detector goes beep (Score:2, Informative)
You don't get it. What you see are the photons deflected by the air off of their original path. When the light is in the middle of the bottle it has actually already exited it. The cameras capture the deflected photons. In a perfect vacuum you would not be able to see anything.
Slashdot Story Misses the More Exciting Point (Score:5, Informative)
This grew out of a system to see around corners. The professor wanted to build a camera that could analyze the path of reflected light to get pictures around ninety degree angles. This is a really amazing concept, moreso than simply getting a camera to take ever increasingly fast pictures.
if you are interested in learning more and have a lecture's worth of time on your hand, please check one out here: http://www.youtube.com/watch?v=aKu20y1f_RU [youtube.com]
Re:What (Score:5, Informative)
No... The OP is correct.
This isn't new technology. It's called "Gated Image Intensifier Photography" and is used for everything from Lidar to special night vision devices that can see underwater. It is one of the few technologies that allows detection of stealth submarines by taking images of the submarine without the backscatter caused by water in front of it. It's one of the only technologies that can track supercavitating weapons underwater. It can also help see through many obscurants.
It's like a flashlight, except you only look at light reflected at a particular time after the flash ( usually a laser ) goes off. As a result, you can choose to see light that is only reflected from, say, 100m away to 101m away. Everything else looks dark and because of this, it's a good technology for seeing through trees and the likes.
If you want to understand gating of image tubes and streak tubes in particular ( what they use - an electronically steerable image intensifier that can track very high speed objects such as bullets being fired from a gun ) just look up Image Tubes by Illes P Csorba. A great book.
What they are doing here is just gating the image a little faster and repeating it often to capture very short duration repetative events in high detail. Not a new technology, just a variation on existing tech.
And you'll find many modern Gen3 NV devices are autogated, meaning they do this automatically, though it's more a way to pulse-width modulate the light coming in so that they can work under brighter conditions, such as when soldiers burst into a room and the enemy turns on the lights inside...
GrpA
Re:i'd be dead before that water balloon pops (Score:5, Informative)
They are talking about shutter rates, not image capture rates... Big difference.
It probably has quite a slow frame rate.
GrpA
Re:Bullshit detector goes beep (Score:5, Informative)
Re:What (Score:1, Informative)
Not true either -- some digital scopes (the super-high-bandwidth ones) work that way, so all you need is a wicked fast sampling circuit, instead of making the whole thing wicked fast, but most "ordinary" digital scopes are perfectly capable of one-shot captures.
And OTOH, most analog scopes I've used, when you use the fastest available horizontal sweep, the beam is dim enough I can't see a single event -- so unless you're using a storage scope or one of those polaroid capture widgets, you're forced to visually average across multiple sweeps here as well.
But yeah, I got a couple analog tektronixes for the odd electronics project. Nothing impresses non-geeks like hooking up a scope to an RS232 line and reading off the bit rate and data format...
Re:Bullshit detector goes beep (Score:4, Informative)
Well I could just say "With your eyes" but I figure the question is "How do you see a single photon?"
You amplify it by converting it to a photoelectron with a very sensitive photocathode, then you add more electrons through either linear acceleration and multiple electron/photon stages or with a MicroChannel Plate ( MCP ) which causes secondary electrons to multiply the number of electrons, then you accelerate it over a short distance to around 5,000 to 10,000 eV and then smack it into a aluminized phosphor screen, which converts the electrons back to photons, but a HEAP of them so they are visible.
They can also focus and steer the electrons inside the tube. That's why it's called a "streak tube"... :)
I have seen photons many times. Kind of cool seeing a picture made from just a few photons, but it has to be REALLY dark to do this and you have to get your own eyes accustomed to the dark as well. The pictures sometimes just look like static until you collect a whole heap of them in a timed exposure.
When you amplify light about 100,000 times and then take a 15 second exposure and it *still* looks dark, you know the original image was exceptionally dark.
GrpA
Re:Hmmm (Score:4, Informative)
You realize that at a picosecond frame rate it would take about a year of watching at 30 frames per second to actually see any motion of a person on a trampoline at all, and maybe a century to observe an single bounce ?
Re:Bullshit detector goes beep (Score:4, Informative)
Ah. Further reading at the MIT site indicates that they are reading at "1THz line rate". They use a varying electric field inside the camera slit to deflect the photons by different amounts onto a 2-D image sensor. Thus, on the sensor, the x-direction contains spatial information, and the y-direction contains temporal information.
They can do this by sweeping the strength of the electric field inside the streak camera's slit quickly. Photons arriving at different times are deflected by different amounts, and thus hit different pixels in the 2-D sensor behind the slit.
Re:What (Score:2, Informative)
Streak cameras with picosecond resolution or below have been available off the shelf for decades. They were really expensive and are still pricey now, even if a lot cheaper. So not within the reach of most hobbyists, although still available to civilians with money or some salvaging luck.
I am not sure about being able to see an advancing light front off of nuclear test footage, at least in a 2D film instead of something like a 1D stream camera. By the 60s, I think the highest speed cameras were on the order of 10,000 fps, which means light would go about 30 km in one frame. Even with current technology, it would be difficult to have a full movie at such speeds of a single event, as the highest speed cameras are usually limited to some set number of frames before requiring some time to reset (something like 1-8 frames are common, although larger ones exist).