Shooting Lasers

<p>I've heard that lasers can severely damage your sensor.<br>

So, what is safe and what is not when shooting lasers?<br>

I have a nice green laser that I've pumped up a bit and have wanted to experiment with it, but want to do so in a safe way.<br>

Thanks!</p>

<p>Hi Jared, <br>

I've shot green lasers in laboratories several times and never had trouble (same goes for shooting green lasers at events). I just make sure that the beam doesn't hit eye or camera.<br>

BTW, I will for sure stay away from tesla coils :-)<br>

Take care and have fun, Georg!</p><div></div>

<p>Thanks! So the caution is to ensure that you are not getting direct laser projection back at the lens. As long as you avoid that your sensor should be fine?</p>

<p>Hi Jared, <br>

to be honest - I really don't know. As written above I've never had trouble - but this doesn't mean that only direct laser projection will harm camera or human eye. <br>

I've shot lasers in laboratories and the Profs told me where I'm safe and where not.<br>

But I could never talk the technicians in the welding-industrie into start their really powerful lasers for a photo-shoot...</p>

 

<p>It depends on the power of the laser. I think I would be less concerned about lasers (in general) than the sun. Now THAT is a powerful spot of light!</p>

<p>Jared: Don't shoot the laser into the lens ... shoot over, under, around, and thru, but not INTO.</p>

<p>Laser can be hundreds or thousands of times as bright as the sun. Look at the sun for a split second and there's a low probability of damage. Look into a laser with any real power and the same quick glace along the beam will burn a hole right through your retina.</p>

<p>I ran a research lab using a bunch of high power lasers for many years. You can take any picture you want of laser light as long as the actual beam itself doesn't enter the lens. Scattered light is generally safe. Just make sure there aren't any shiny surfaces around that might produce a specular (mirror) reflection</p>

<p>I'd say the basic rule is that if the label on the laser requires you to safety glasses to work with the laser, don't point it at the camera. If it's a red or green "laser pointer", then you don't need to worry much. If it's some surplus laser run from an external power supply, then you can worry. Anything rated class 3B or class 4 is dangerous and even a brief, accidental, glimpse directly into the beam can damage your eye. Class 3R is less dangerous but still needs care in use. Class 1 and class 2 lasers are generally safe unless you do something really stupid with them.</p>

 

<blockquote>

<p>I have a nice green laser that I've pumped up a bit and have wanted to experiment</p>

</blockquote>

<p>That's a very disturbing statement from someone who had to ask this question. If you don't know what you are doing (which your question suggests is the case), unless you're tired of being able to see out of both eyes you shouldn't be messing with lasers you have "pumped up a bit".</p>

<p><a href="http://www.ariven.com/files/images/warning-laser-640.png">http://www.ariven.com/files/images/warning-laser-640.png</a></p>

<p> </p>

<p>Our long-haired dachshund (L. canis goofus) loves to chase either my red or green laser spots around the house. We just have to be careful so as not to shine them at, or near her.</p>

<p>I was the chief engineer for a company that built high-power pulsed CO2 lasers and used them for stripping paint. A single pulse from one of our lasers would take a spot of paint off right down to the underlying metal! On the wall next to our test area we had a large sign which said, in bright red letters:<br>

DO NOT LOOK INTO LASER WITH REMAINING EYE!<br>

I would recommend that you go to a laser safety company and buy a pair of protective goggles for the specific wavelength of your green laser, and always wear them if it is powered up. As Bob said, one tiny fraction of a second flash into your eye, and you will have a hole in your retina, and maybe more damage than that!</p>

<p>Back in my one test/QC lab I have a small 1.5KW YAG laser set up that I use to weld stainless steel up to about 2o thousandths thick. It's obviously fairly powerful and goggles are necessary. Reflections off mirror-like surfaces are the danger.<br>

20 years and zero injuries - by observing proper precautions. Know what you are doing !</p>

<p>Jim M.</p><div></div>

<p>I have an off the shelf green laser pointer that I've turned the pot up on slightly. It's noticeably brighter than my non-modified one. It is not eye friendly by any means and I'm fully aware of that danger. I didn't mean to start a discussion on the dangers of lasers. I'm fully aware of the risk to my eyeballs.<br>

It's about the danger of lasers to my sensor. I have heard horror stories of people at concerts with permanent sensor damage from the lasers there.<br>

I really just want to do some light painting or long/multiple exposures and want to make sure that as long as I'm careful about where I point it (same with my eyeballs) that it's going to be a good tool and not break anything.<br>

Thanks, all!</p>

<p>Yes there were several cases of sensors being killed at concerts and shows by lasers, all when the beam went directly in the lens. One video I saw even went backwards and forwards once or twice but on the last pass it killed the sensor instantly.</p>

<p>There are several videos of damage caused to sensors, normally a few lines across the sensor turn white. This damage seems permanent.</p>

<p>Other than sheer stupidity, the usual reason people get a direct hit by the beam on their sensor is that they are trying to position their camera close to the path of the beam in order to get enough exposure to record an image of the beam as it goes through the air. The closer to the beam they get, because of highly peaked forward scattering, the brighter the beam. Don't do it this way. Instead, the "fog" obtained by blowing lightly over a dewar of LN2 or dry ice is your friend when trying to capture visible laser beams. Don't even think about blowing cigarette smoke in a laser lab to record the beam path -- at best, you'll get thrown out and never invited back. At worst, you'll also receive a bill for the damage you caused. </p>

<p>On a slightly different, but related note, use multiple (manual, tripod mounted) exposures for laser lab shots: One exposure with good color balance to get peoples' faces, another to get the expected ;-) red-blue gelled backgrounds, and a third exposure with the shutter held open and the room completely darkened to record the beam as it passes through the lightly "fogged" beam path. </p>

<p>HTH,</p>

<p>Tom M</p>

<p>" another to get the expected ;-) red-blue gelled backgrounds, "<br>

Ok, that one bugs me.<br>

Why is it that people believe science happens in a disco? In no lab that I've ever been in, has there been purple or red light. Dim yellow, sure, and lots of terrible fluorescent office lighting... but never purple and red. Is it the CSI effect? And what happens when they expect it, but never see it? <br>

<br /><br>

More on topic: what about a pinhole image of a laser beam... has that ever been done?</p>

<p>Re: red-blue gelled backgrounds - Just in case my intent wasn't clear, note my use of an emoticon to try to suggest sarcasm and my own frustration at this.</p>

<p>Re: pinhole images of laser beams - FWIW, this was done a lot in the old days, ie, 1960's and '70's. Specifically, many of the first laser beam profile measurements of IR lasers were made by scanning a pinhole in front of the beam. These days, about the only use of a pinhole with a laser is in the form of a <a href="http://books.google.com/books?id=tjjSZsHBkEMC&pg=PA106&lpg=PA106&dq=pinhole+laser+higher+order+modes+clean+beam&source=bl&ots=_G4XrVO5V0&sig=y0xYBcDpsiTQpyYJVU04_fLCgEQ&hl=en&sa=X&ei=aYdfT73LK4fX0QHZ-unDBw&sqi=2&ved=0CD0Q6AEwBA#v=onepage&q=pinhole%20laser%20higher%20order%20modes%20clean%20beam&f=false">spatial filter</a> to clean up the transverse profile of a laser beam.</p>

<p>Tom M</p>