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FrozenGate by Avery

Did I catch laserbeams in flight?

Things said:
AFAIK there is only 1 camera in existence that is able to capture light travelling. There is a video of it on Youtube somewhere. However, even then it isn't really capturing it in a single shot, it fired the laser hundreds of times and gets a frame at different times, each time, until you have a video.
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Are you refering to the holographic technique called Light-in-flight? In this setup you use a short laser pulse which is devided into an object beam and a reference beam to a holographic plate. The object beam pulse travels along the object and reflect onto the holographic plate. By sweeping the reference beam over the plate, different parts of the reflected object pulse will interfere with the reference beam pulse in different parts of the plate. After development, you can replay the pulse as it travels along the object.

KUBOTA HOLOGRAPHY LAB
 
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ElektroFreak said:
What you are calling the ends of the beams I believe are just the effect of the sensor refreshing, not actually the backside of the beam traveling away.
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Okay. This is dnar's (still) pic not taken with an iPhone;

dnarspicnottakenwithiPhone.jpg

LSRFAQ said:
We would need the "theory of operation manual" for that specific CCD/CMOS sensor, and a programming team telling us how they did the MP4 compression, to answer your question 100%. Some times you have to take things on faith alone and use assumptions.
Steve
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Thanks Steve. I will attempt to replicate this with at least 5 different cameras. (still, film, HD, [and hopefully ultra high-speed video])
Roy G. Biv said:
Are you refering to the holographic technique called Light-in-flight? In this setup you use a short laser pulse which is devided into an object beam and a reference beam to a holographic plate. The object beam pulse travels along the object and reflect onto the holographic plate. By sweeping the reference beam over the plate, different parts of the reflected object pulse will interfere with the reference beam pulse in different parts of the plate. After development, you can replay the pulse as it travels along the object.

KUBOTA HOLOGRAPHY LAB
Click to expand...
Thank you very much for this. It provides me with a great deal of information to work with. +Rep :D
 
In order to see the 'end of a beam' you camera woud need to operate in the range of a million frames per second - and even at that rate, the end of a a beam still does 300 meters per single frame.

The effect is due to the framerate of the camera though: one frame the beam is there, the next its not. How this renders is totally up to the cameras firmware, but in order to directly observe the point a laser beam stops a camera needs to be incredibly fast, producing 3 frames between the beam being there and being absent. Ideally the middle of those 3 frames would actually show the end of the beam, but afaik there are no consumer cameras that work at these speeds.
 
The same happens on many digital sensors, but rarely as pronounced as the iphone. In order to capture the "end" of the beam the response time of whatever medium used to capture the image would have to be incredibly fast, thus it would cost many, many dollars to build or obtain a device that could do it. It's safe to say that no one here has anything that could.

Also you're assuming that the laser beam shuts off instantaneously. In reality at the time scale we're talking about here the beam would likely fade away instead of disappearing instantly. Everything has a cut-off time, and at very tiny time scales like this that cut-off time can be an eternity.

Let's say for simplicity that we wanted an exposure in which a beam of photons travels ~1m. Light travels roughly 299792458 m/s, so the exposed medium's response time would need to be 1/299792458 of a second or ~3.34ns.
 
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I will eat a sculpture of ElectroFreak's elbow made of burnt yogurt if you can reproduce this on a film camera. :tinfoil:
 
Easy..

Turn the film camera up, way past is max sync rate (the fastest shutter speed in which the entire plane of film is exposed at the same time)

When you press the shutter release, have a laser turn on, or off while the front curtain is only halfway across the film plane.

:)
 
Did anyone also consider the fact that the laser is also being turned off and on rapidly (notice the other beams too :D). If you think about it logically the cameras "Shutter" is open for, lets say 1/10th of a second for arguments sake. The scanners are moving faster than that... possibly up to 30 fps. As we've established shutter speed of the camera and compression plays a part in this, but if you also have a rapidly moving and "pulsing" beam within that 1/10 of a second the laser could be "pulsed" 3 times.

This could cause a few things... One the laser will be more vivid on film/photo camera than on video. Two compression can drop frames/blend frames/etc so this effect could happen.
 
aside from the whole camera action, it is possible to slow down light to about 38 mph,
Physicists Slow Speed of Light. in that article. but from what i understand it compresses into the first layer of electro-magnetic energy, but exits at the same amount of time it took to go in.
 
CMOS sensors capture the image one line at a time, kind of like how a CRT "scans" out and image, while CCD's take full sensor images all at once, much like a traditional film camera.
 
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Gryphon said:
CMOS sensors capture the image one line at a time, kind of like how a CRT "scans" out and image, while CCD's take full sensor images all at once, much like a traditional film camera.
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Thanks for the info. +rep
hakzaw1 said:
I think I have found another video showing something that we cannot see but a vidcam records it.. look at the one on the right.. I have never seen fans looking like those...I wish...

http://www.houstonvisuals.com/event-services.html

I dont know how to insert this so if you can please do
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not sure how to insert, but I have the link to the .swf file:
http://www.houstonvisuals.com/images/Lasers.swf
Lasers.swf
 
thanks for that Cade.



I still would like to see lasers do that in person..len
 
hakzaw1 said:
thanks for that Cade.



I still would like to see lasers do that in person..len
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In person? :undecided: maybe with this device;


I think the guys at Time Warp are my only hope here.
 
seems to me since we know the speed of light and we have the ability to take damn quick analog photos, one could position a laser aimed at a target a handful miles away take the picture at the right distance you should see the beam enter the frame if the you start the exposure before the laser is fired first then at the end of shot the laser comes in view. It would be blurry haha but a computer could clean it up some. Anyone want to try with a uber nice old 35mm and laser with a very low divergence? :P
 
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