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-   -   trying to record laser beams! (https://www.dvinfo.net/forum/open-dv-discussion/125292-trying-record-laser-beams.html)

Cole McDonald July 4th, 2008 02:46 AM

trying to record laser beams!
 
I'm trying to get video footage of an industrial laser in action. Specifically this machine: http://www.hirschinternational.com/P...le-Lasers.aspx

I'm not sure what wavelengths it's laser is, so I'm really just asking if anyone's done it and what they used to make it happen. When it's firing, you can't see the beams even through the little gouts of smoke it makes (which are really cool!).

Steve House July 4th, 2008 08:28 AM

Quote:

Originally Posted by Cole McDonald (Post 903028)
I'm trying to get video footage of an industrial laser in action. Specifically this machine: http://www.hirschinternational.com/P...le-Lasers.aspx

I'm not sure what wavelengths it's laser is, so I'm really just asking if anyone's done it and what they used to make it happen. When it's firing, you can't see the beams even through the little gouts of smoke it makes (which are really cool!).

A little research leads to the info that the laser in that machine is a CO2 laser. CO2 lasers operate in the infrared, producing a beam which is, of course, invisible to the eye and most cameras. If it was in the visible spectum you could blow in a little mist from a fog machine to scatter the beam and make it visible from the side but since IR isn't visible to begin with, that tactic won't work. I'm afraid there might not be anyway to do it.

Martin Catt July 4th, 2008 08:36 AM

Odds are, it's an IR laser, so there is no visible beam (unless they have a "guide" beam, usually a red laser in parallel with the cutting beam to show the strike point). If there's no guide beam, then there's nothing visible for the camera to record.

IF there's a guide beam, then it's possible to make it visible by lightly smoking the air. You need some kind of suspended particles in the air to scatter some of the guide beam, plus the room should be kinda dark. Cigarette smoke, incense, or canned smoke for special effects works. I'd post a link for canned smoke, but they're not an approved DVInfo supply house. Google "canned smoke" and follow a few links.

Martin

John Miller July 4th, 2008 08:40 AM

CO2 laser units usually have a secondary visible laser to ensure correct alignment/targeting. Often, they are blue/green. A possible, though unlikely, option is to find out if the alignment laser can be turned on at the same time as the primary operation.

EDIT: Cross posted with Martin.

Ray Bell July 4th, 2008 08:49 AM

I work with these lasers... the other posters here are correct...

The laser you are asking about is a " incoherent laser " you can't see it
and the camera can't see it...

When I align my lasers during maintenance I use phos paper to illuminate the
focus point, but you will never see the beam, only the focus point on the paper...

One way though for you to get your desired effect would be to let the laser cut into
a sheet of metal... might even cut into a sheet of foil....

for our needs we cut into small sheets of gold... when our laser cuts the gold it
produces a cool green color of light as it burns the gold.... that can be filmed...

also of note... you should also be aware that laser can cut through materials...
if your camera gets any of the beam into the lens it will burn out the pixels on the
camera sensor.. so be careful

James McBoyle July 4th, 2008 12:33 PM

If the laser is visible in the infra red, what about using a camcorder that can see IR with something like Sony's 'super nightshot'. Their HD1000, for instance, can do this and even has a built-in IR light, so maybe mixing a 'night' shot with a regular visible-light shooting could work? (sorry if this is a daft idea that won't work, but I had to try)

John Miller July 4th, 2008 01:14 PM

Unfortunately...CO2 lasers operate at 10,000nm - way down in the IR spectrum whereas as CCD sensors have a peak sensitivity at around 1,000nm (which is why an IR filter is usually put in place for daytime use).

Cole McDonald July 4th, 2008 07:41 PM

Quote:

Originally Posted by John Miller (Post 903185)
Unfortunately...CO2 lasers operate at 10,000nm - way down in the IR spectrum whereas as CCD sensors have a peak sensitivity at around 1,000nm (which is why an IR filter is usually put in place for daytime use).

I think this is the bit of info that lets me know the reason it didn't work for me. My camera does see the blinking LEDs on my TV remote, so I know it shoots the IR septrum a bit, but not quite that high.

Thanks so much for all your responses.

Chris Soucy July 5th, 2008 12:51 AM

Hi Cole.........
 
Well, you set me a challenge there, and no mistake.

I now know a great deal more about lasers than I did this morning.

My conclusion?

Well, I can't see any way you're going to "see" the laser itself.

It's non - ionizing parameters make phosphorescence/ electo - luminescence out of the question, and no man made sensor can get down that far (well, anything the military might be willing to part with, anyway).

What you MIGHT be able to do is show where it is (it's line of travel).

If you can rustle up either a steam source, or, more likely, a "dry ice" source, to shroud the beam path, the beam itself will cut a swathe through it, turning the vapour to either invisible water vapour or invisible CO2 gas respectively.

Whether the beam path will be wide enough to show a distinct path through a vapour cloud is, I guess, up to you to determine.

Something like a sealed container, half filled with water & a block of dry ice, close fitting lid and an attached hose with a suitably shaped nozzle on the end should allow you to produce a stream/ ribbon of CO2 "steam" fine enough to pick out the beam as it cuts through it.

If you can, actually, get a "pickup" on this, then all you need to do in post is add the James Bond (Goldfinger) fireworks to the "black line" created above.

May not be much, but the best this amateur scientist can come up with.


CS

Dean Sensui July 5th, 2008 02:52 AM

If you get really desperate, you can always use After Effects.

A. J. deLange July 5th, 2008 05:56 AM

Buy a laser pointer (green are the brightest but people might find red more what they are accustomed to thinking a laser should be), tape it to the side of the real laser or conceal it some way in the scene or have an assistant hold it out of the scene aligned so the beam appears to be emanating from the real laser at the appropriate point or use mirrors to acheive this. Then blow smoke and have at it. It's all done with smoke and mirrors!

Tom Majeski July 7th, 2008 01:01 PM

Cole,
I have a laser like that, it's my other part-time hobby-business. (www.thelasercutter.com)
You just can't capture the beam of a co2 laser. I do have some footage of cutting wood and lexan I can post.
I filmed it with my cheap Panny camcorder. I won't use my XH-A1 because once in a while I'm blinded by a stray reflection. (yes I forgot to put on my wavelength-specific safety glasses) and my concern is a stray reflection MIGHT possibly damage the lens or CCD. I know it would be extreemly out of focus, but still...

Mine has a red visable targeting laser you can see, but it's not the cutting beam.

Tom


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