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View Full Version : placing a digital camera close to the laser head



stan kern
03-02-2010, 11:00 PM
Is there any problem placing a digital camera inside the enclosure while the laser is running(making sure its out of the way of the movement of course)
Can it harm the camera ?lens?

Darren Null
03-02-2010, 11:28 PM
There is indeed a problem. The case on your machine is there to stop reflected laser rays escaping and damaging your retinas. Whilst modern CCDs can cope with more than the human retina (in visible wavelengths- don't know about laser), I wouldn't put a camera inside the case unless I was prepared to lose it. It might not happen; but then again it might. The lens would probably be fine, but it's entirely possible you could burn out the CCD with a stray beam.

You could -as an alternative- film through the clear plastic part of the case and throw a torch or two inside the machine to light up the area you want to film. Adequate lighting and a colour balance adjustment afterwards ought to cope with all but extreme tinting on the plastic case. If you want a particular angle, you can throw a mirror in there too.

Rodne Gold
03-03-2010, 4:32 AM
Why do you want to put the digital camera there?

Michael Hunter
03-03-2010, 5:06 AM
Not so good with a camera? Get your lens laser frosted and no-one will ever know!


Seriously - the camera is unlikely to come to harm.
Much more control though, if you shoot through the lid. A desk light or two shining down through the lid would illuminate more reliably than torches and you should be able to get an angle where there are no reflections.

Niklas Bjornestal
03-03-2010, 6:02 AM
If you're worried about the camera just cut an protection "lens" from clear acrylic and put in front of the lens.

Frank Corker
03-03-2010, 7:54 AM
I'd also be doubtful about putting a digital camera inside for fear of damaging the CCD. It's a bit like taking a picture of the sun. Putting it inside the machine may result in some damage to the lens coating. If you have to get this shot, use the zoom from some safe distance and I'd avoid staring through the view finder. If you go on YouTube you will see there are a few that have already done this, but you're asking for opinions here.

Dan Hintz
03-03-2010, 9:47 AM
I see no problem with this, assuming the material is not reflective enough to shoot a stray beam towards the CCD... in those cases, Niklas' suggestion is a good one. That said, I wouldn't go putting a $5k DSLR in there ;)

But I have to ask along with others... why?

stan kern
03-03-2010, 10:02 AM
I'll stop that practise ,carry on shooting from the outside.Somethimes i like to record the cut just for utube ,show what a laser can do.
Thanks for all the info

Anthony Scira
03-03-2010, 10:39 AM
I have done it, I used a camera phone. And now that this thread has got me thinking I prolly would not put an expensive camera in there. The cost for a cheap video camera I do not think it will hurt it.

Here is a little clip I uploaded to you-tube the other day from my Nexus One.

http://www.youtube.com/watch?v=O1hdkvm47pQ

Dee Gallo
03-03-2010, 10:57 AM
Here is a little clip I uploaded to you-tube the other day from my Nexus One.

Thanks Anthony...as if I don't spend enough time watching my own laser, I needed to watch a video of yours! hahaha

Daniel Reetz
03-03-2010, 11:01 AM
There's nothing magical about the IR from your laser that would damage a camera. I mean, this low-frequency IR doesn't penetrate glass easily -- that's why you can etch glass with it, and why the laser has optics made of other materials. This means that little of the IR beam will actually reach the sensor, which, incidentally, has an IR filter over it, too, because silicon is very responsive to IR.

However, the spot where the laser impacts the workpiece has visible light components that are very, very intense. The lens of your camera will focus that bright spot on the sensor, which has the potential to damage photosites there. But if your laser is moving at all, the chances that one spot on the sensor will heat up and die is pretty slim.

If you want to do this, I'd say just get a cheap, used camera off eBay or used and plan on its eventual destruction. Otherwise, this really doesn't pose much of a problem.

Dave Johnson29
03-03-2010, 11:09 AM
Is there any problem placing a digital camera inside the enclosure while the laser is running

Hi Stan,

Nope, as long as it is not in a direct line of the beam. The laser is just heat. It is absorbed by most things and the reflections, if any, will be tiny, tiny tiny. The CO2 wavelength is no different to that from the heater in your house or a select part of the IR spectrum from a log-burning camp fire. The thing about the laser is that the heat is concentrated, not a magic beam.

Some years back I mounted a small spy-type camera on the moving head and it transmitted the signal back out to a VCR. I used it for weeks and other than occasional smoke on the lens, all was fine.

Dan Hintz
03-03-2010, 11:17 AM
The laser is just heat. It is absorbed by most things and the reflections, if any, will be tiny, tiny tiny. The CO2 wavelength is no different to that from the heater in your house or a select part of the IR spectrum from a log-burning camp fire. The thing about the laser is that the heat is concentrated, not a magic beam.
It's heat as long as the material absorbs the wavelength. A reflective surface, such as polished aluminum, will reflect those wavelengths back to the camera. Some here believe the reflection has etched their covers, and while I have a hard time believing the beam is focused enough after traveling 8"+ back to the cover to etch the glass, a camera near the carriage would have a much higher chance of having its lens partially etched/fogged.

Dave Johnson29
03-03-2010, 11:37 AM
Dan, I took the reflective surfaces as a given because I think everyone here accepts the use of the mirrors for beam delivery, but perhaps I should have added it. I actually had it in the first par but backspaced it out as superfluous. :)

I too cannot see how the reflection could etch the cover. On occasions I run my laser with the cover open. maybe the reports of "etching" are deposits of vaporized materials.

When I do footballs for the local HS, I put the football in an oval cutout. Sometimes the stitching and the degree of inflation makes a lump and the ball rocks slightly during marking. I put a wood wedge in the interlock switches, and hold the ball steady by hand.

I use vectoring for the logo so it is only about 2 minutes to hold it. I do not come away with cooked hands or fried eyeballs. I am NOT advocating it for anyone else, I am just saying I do it and I ain't cooked yet. Half baked maybe, but that's another story. :D:D

I have been experimenting with CO2 lasers for many years and haven't yet been burned. Not even close. I am sure that statement will bring out the nay-sayers, but to me it is no worse than using my table saw without that stupid over-blade guard. Sure, I could rip fingers off, but I would have to do something really stupid to do so. Just call me Billy-9-fingers. :D:D

Scott Shepherd
03-03-2010, 12:49 PM
Some here believe the reflection has etched their covers, and while I have a hard time believing the beam is focused enough after traveling 8"+ back to the cover to etch the glass

There was a photo on here at one time where it did just that. I doubt it could be easily found, but I recall seeing the photo someone posted about it, along with what happened. That was a couple of years ago.

Gary Hair
03-03-2010, 12:58 PM
I have a hard time believing the beam is focused enough after traveling 8"+ back to the cover to etch the glass

I believe it could happen, but I believe that it would have to be the "perfect storm" - the right material, the right speed, power, angle, etc. It's "possible" but not likely to happen on a regular basis. I also doubt you could reproduce the circumstances without some serious trial and error.

I'm not willing to risk my eyesight on that low probablility but I'd take a chance with my camera.

Gary

Darren Null
03-03-2010, 12:59 PM
One nay-sayer coming up

I have been experimenting with CO2 lasers for many years and haven't yet been burned. Not even close.
The thing about retinas, is that you only have to be unlucky or wrong once. I always wear goggles for door-open stunt engraving. No other precautions...the rest of me will heal.

Dave Johnson29
03-03-2010, 1:12 PM
Hey first nay-sayer, :):)

Good point Darren, I wear glasses to see so in effect they would be my first line of defense. But goggles would be a good idea if you don't need glasses, I should have mentioned it. BUT, check my beam reflection experiment for more fun.

OK, call me one-eye-Billy-9-fingers-scar-face :D

I gotta get a real job, too much time on my hands. :)

Darren Null
03-03-2010, 1:25 PM
I don't know whether glasses would stop the beam, or just focus it better. The goggles I have, you could get a pair of glasses inside...$50 on eBay and they were manufactured in Israel; specifically for the CO2 laser spectrum...can't remember any more details.

Dave Johnson29
03-03-2010, 1:32 PM
I don't know whether glasses would stop the beam, or just focus it better.

It's just heat Darren, it would start to melt the lens but as Dan has said, that is a looong way for the beam to travel focused enough to do any damage. However, I believe it is all moot after the beam reflection experiment I posted.

I have 7-1/2" adjustment under the focus point for my table and dropping just two inches the beam has diverged enough to not mark paper. I think bouncing back to someone's face is a long stretch. The beam is already at the point of diverging at the point of focus or just beyond. I cannot see a reflection refocusing the beam. I have been wrong before and no doubt will be again though. :)

The thing is if a person feels better wearing the protection then by all means do it. Freak stuff can and does happen.

Frank Corker
03-03-2010, 2:13 PM
Well it's not my camera, go for it, then post the results.

Dan Hintz
03-03-2010, 2:20 PM
I don't know whether glasses would stop the beam, or just focus it better. The goggles I have, you could get a pair of glasses inside...$50 on eBay and they were manufactured in Israel; specifically for the CO2 laser spectrum...can't remember any more details.
The material glasses are made out of is quite opaque to the far-IR wavelengths of our lasers, hence the reason we use ZnSe lenses instead of standard optical glass. Your glasses would stop it without issue.

Your $50 eBay goggles could be replaced with a $5 pair of work glasses from Harbor Freight... acrylic, same issue as glass.

Darren Null
03-03-2010, 2:43 PM
Your $50 eBay goggles could be replaced with a $5 pair of work glasses from Harbor Freight... acrylic, same issue as glass.
Ah well. To be honest they were overkill; they are for the metal-cutting kilowatt lasers where specular reflections can be a real problem. And they're designed so nothing gets in at the edges. Might be $45 wasted, but I really enjoy having binocular vision and it seems like a small price to pay to know for sure.

stan kern
03-04-2010, 10:05 PM
So i get the idea that if you don't bypass the switches and you're pearing through the plexi view window your eyes are protected even if you're following the arc---correct or should one not look at it.
i'm always checking the burn and thought the view wndow protected the eyes

Darren Null
03-05-2010, 12:39 AM
The plexi stops much of the specular reflections from the laser, so you're not going to lose your sight from watching it. That said, there's quite a lot of light in there...like arc-welding, but less so. I look at it, but don't stare at it, if you see the difference.

Dan Hintz
03-05-2010, 8:00 AM
Don't treat it like your favorite telly program, more of an amusing Geico commercial, in other words...