# Could this work? Anti-photographer laser shield **URL:** \ **Category:** Factual Questions\ **Created:** [September 22, 2009, 4:15am UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049 "2009-09-22T04:15:49Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 4:04pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/21 "2009-09-22T16:04:00Z")
The biggest problem I see (heh) with the idea is this. For it to work, at least at the power levels I’ve described above, the “thing” emitting/aiming the light towards the camera needs to be in the FRAME that the camera is recording. So lets say I am a good distance away and I want to take a picture of Russian Billionaire. So, I get out my telephoto lens and zoom right in so that his body takes up decent part of the frame. So, say the frame at the subject distance is 10 by 15 feet. It doesnt seem remotely practical at first glance that the yatcht could have these things every 10 feet vertically and 15 feet horizontally. Yeah, in theory, the things could be outside the frame of view and side glare could mess up the pic, but that would be much more hit and miss (heh) and also require an order or two or three times more power to work. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [September 22, 2009, 4:14pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/22 "2009-09-22T16:14:52Z")
**Balthisar** nailed it. Why bother when the countermeasure is a film camera? ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 4:15pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/23 "2009-09-22T16:15:07Z")
> [@billfish678](#): > > It doesnt seem remotely practical at first glance that the yatcht could have these things every 10 feet vertically and 15 feet horizontally. On second thought, maybe its not quite so bad. If you just want one deck “safe” you just have these things every 10 to 15 feet along the railing. Still gonna be a pain in the butt though. ---
**Author:** ![Rigamarole](https://avatars.discourse-cdn.com/v4/letter/r/77aa72/32.png) [@Rigamarole](https://boards.straightdope.com/u/Rigamarole)\ **Post date:** [September 22, 2009, 4:24pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/24 "2009-09-22T16:24:44Z")
> [@billfish678](#): > > On second thought, maybe its not quite so bad. If you just want one deck “safe” you just have these things every 10 to 15 feet along the railing. Still gonna be a pain in the butt though. Other issues aside, if he’s dropping $1.2 billion on a yacht, he doesn’t seem like the kind of guy for which practicality is a huge concern. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 4:30pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/25 "2009-09-22T16:30:46Z")
> [@Dag\_Otto](#): > > **Balthisar** nailed it. Why bother when the countermeasure is a film camera? Film is not going to be immune to this system. Depending on which film and CCD design, I could make an argument either one or the other being more subsceptible to this system. To actually figure this out requires way more research and or experimentation than I am willing to invest. If I had to guess, I would say film would have less of a problem, but not so much so that would only have minor or no problems. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [September 22, 2009, 4:40pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/26 "2009-09-22T16:40:29Z")
> [@billfish678](#): > > And while that intensity level would be quite unpleasant to look towards with your eyes, its probably not going to cause instant damage (note, DO NOT take that as suggesting its ever safe to look towards any laser, at ANY power level). If you purposely stared at it, you could probably cause permanent damage, but the glare would be sooooo bad and unpleasant you probably have a hard time forcing yourself to do it. The aversion response. I don’t have my CSLO certification up to date, but certain classes of lasers of certain outputs are considered “safe” because a normal human will instinctively look away before any damage is done. But like you say, some people are probably apt to force themselves! :smack: ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [September 22, 2009, 5:17pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/27 "2009-09-22T17:17:51Z")
OK, here’s something that _might_ be related to what is being talked about here. > [@Wired](#): > > PirateEye detects camcorders and pinhole cameras in the act of bootlegging movies, according to Trakstar. The remote-controlled device looks like a mechanical replica of Darth Vader’s head. Perched on a stand directly below the movie screen at the front of the theater, the small black box shoots brief, almost invisible pulses of light at the audience. > > Offending camera lenses bounce back a telltale reflection that the device senses, then records on a digital snapshot captured with a built-in digital camera of its own. If the machine spots a suspected pirating camcorder in the audience, it then sends out an automated alarm to in-theater security or law enforcement. [Full article](http://www.wired.com/entertainment/music/news/2004/11/65683?currentPage=all) The system described here is for blocking movie theater piracy but could a similar system be used to locate a camera and then, instead of calling security, it just fires a laser at the detected camera? I guess it would have to fire continuously though so that probably wouldn’t work. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [September 22, 2009, 5:24pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/28 "2009-09-22T17:24:46Z")
> [@billfish678](#): > > Film is not going to be immune to this system. > > Depending on which film and CCD design, I could make an argument either one or the other being more subsceptible to this system. Maybe I’m missing something. I thought the OP stated that the system fired upon detection of a CCD. How would it detect a film camera, unless the light meter used CCD? Even then, a good photographer doesn’t have to rely on a light meter. Set your exposure manually and shoot. To defeat that, the anti-camera system would have to be on 100% of the time, in all directions. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 5:27pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/29 "2009-09-22T17:27:51Z")
> [@tanstaafl](#): > > OK, here’s something that _might_ be related to what is being talked about here. > > [Full article](http://www.wired.com/entertainment/music/news/2004/11/65683?currentPage=all) > > The system described here is for blocking movie theater piracy but could a similar system be used to locate a camera and then, instead of calling security, it just fires a laser at the detected camera? I guess it would have to fire continuously though so that probably wouldn’t work. Man, if they have \*\*Darth Vaders \*\*head on a stick down front that alone should be enough to discourage piracy 🙂 Yes that system is related to what we are talking about in terms of detection. As for firing lasers continously, that aint a problem. Some fire slowly, some fire fastly, and some, if not most, can fire continously. So continous laser power aint no problem. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 22, 2009, 5:28pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/30 "2009-09-22T17:28:23Z")
Wouldn’t the optics of the camera make this irrelevant in the first place? If I shine a laser at a camera lens, all the camera is going to pick up (assuming it’s focused) is a single bright spot a the location of the laser. It’s not going to wash out the entire image. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 5:38pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/31 "2009-09-22T17:38:48Z")
> [@Dag\_Otto](#): > > Maybe I’m missing something. I thought the OP stated that the system fired upon detection of a CCD. How would it detect a film camera, unless the light meter used CCD? Even then, a good photographer doesn’t have to rely on a light meter. Set your exposure manually and shoot. To defeat that, the anti-camera system would have to be on 100% of the time, in all directions. There are two issues here. The detection and the firing back so to speak. While I can see how a CCD system might be somewhat easier to detect than a film system, for reasons I dont feel like typing out, I am reasonably sure its detectable as well. The other issue is whether the laser/whatever light overwhelms a film camera as well as a CCD camera. My WAG answer is probably, though not quite as well, but good enough. Why wouldnt you have the system on all the time? Or at least anytime you are worried about photogs being the area. I think you guys are thinking the photog snaps a pic and the system has to react fast enough to “fire” a laser beam at it. That is at least theorectically doable. However there is no reason the system cant detect a camera, even when it is NOT taking a picture at that moment, and continously shine a laser/whatever beam at it. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 5:42pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/32 "2009-09-22T17:42:50Z")
> [@Chronos](#): > > Wouldn’t the optics of the camera make this irrelevant in the first place? If I shine a laser at a camera lens, all the camera is going to pick up (assuming it’s focused) is a single bright spot a the location of the laser. It’s not going to wash out the entire image. That bright spot spills light all over the CCD, even if its hitting just one pixel. Imagine a giant field of many rice paddies. Dump a buttload of water on just one. The other paddies are gonna end up seeing that water as well. Besides, I ACTUALLY tried this morning, and yep, it happens. Sure, there are ways to mitigate it, but it can be a problem. ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [September 22, 2009, 5:50pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/33 "2009-09-22T17:50:17Z")
> [@billfish678](#): > > I think you guys are thinking the photog snaps a pic and the system has to react fast enough to “fire” a laser beam at it. That is at least theorectically doable. However there is no reason the system cant detect a camera, even when it is NOT taking a picture at that moment, and continously shine a laser/whatever beam at it. Yeah, that’s what I was thinking. The system I linked would detect the camera but I was thinking it would have to do something in the very brief window of time while the shutter was open. But yeah, if you just detect any camera aimed in your direction then bathe that area with lasers/ir/whatever then it would probably work. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [September 22, 2009, 5:53pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/34 "2009-09-22T17:53:42Z")
> [@Francis\_Vaughan](#): > > There are military systems that detect any nearby optical device by reflections off the surface of the lens. They are intended for battlefield use, and are able to detect binoculars and nightsights if they are turned towards the detector. A modulated scanned laser would probably work for such a system, along with some nifty processing of the reflected beam. But how big are these, and at what range do they work? ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 7:52pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/35 "2009-09-22T19:52:49Z")
I dont think some folks realize how damn BRIGHT a laser beam is when you look INTO it. My run of the mill green laser pointer is about 4 milliwatts. It runs off of 2 AAA batteries. Its about the size of a large pen. It has an exit beam of about 1/8 of an inch (3 millimeters). If I sit inside in the daytime in a brightly lit room and shine in on my hand, and just look at the spot on my hand, it is actually somewhat unpleasant to look at. Just doing that leaves some temporary blind spots in my vision. If I do the same thing at night in a dimily lit room it is much worse. If (and this is a damn stupid and dangerous idea) I shine it directly into my eye it would actually theorectically hurt, temporarily blind me in that eye, and even possibly do permanent damage to my retina. It would theorectically be the optical equivalent of being wacked in the funny bone with a baseball bat or pissing on an electric fence. Remember is a measely 4 MILLIWATT laser. A normal 2 D cell battery flashlight puts out a couple of WATTS of light by comparision. Remember, there are a THOUSAND milliwatts in one watt. A single light bulb on a string of christmas tree lights puts out something like a 100 milliwatts. The fact that a laser sends all the light in the same direction is what makes it so “powerful” for so little power actually put out. I took my camera outside just now. Its a bright sunny day, which favors the camera here. Took a picture facing directly into my tiny laser pointer. The large majority of the picture frame is unusable. ---
**Author:** ![Tastes\_of\_Chocolate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tastes_of_chocolate/32/3232_2.png) [@Tastes\_of\_Chocolate](https://boards.straightdope.com/u/Tastes_of_Chocolate)\ **Post date:** [September 22, 2009, 8:29pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/36 "2009-09-22T20:29:46Z")
You all are forgetting the boat part here. You know those things that bob up and down on large bodies of water, rocking with each random wave that comes in? How the heck are you going to get any kind of accuracy from that platform? ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 22, 2009, 8:34pm UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/37 "2009-09-22T20:34:27Z")
> [@Tastes\_of\_Chocolate](#): > > You all are forgetting the boat part here. You know those things that bob up and down on large bodies of water, rocking with each random wave that comes in? How the heck are you going to get any kind of accuracy from that platform? If the scenario is stable enough for a phographer to get a picture worth a crap, its more than stable enough for an automated system to stay locked on the photographer/camera. Also, remember large boats are actually pretty stable. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [September 23, 2009, 5:46am UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/38 "2009-09-23T05:46:53Z")
> [@billfish678](#): > > I dont think some folks realize how damn BRIGHT a laser beam is when you look INTO it. So you are saying that it is impossible to lower the light level of a laser to be of non-dangerous level? While I’m by no means a laser expert, I can’t think of any reason why that would be so. A laser is just a light source which lines up the photons to travel a parallel course. If I go out and stand on the planet Pluto, the photons coming from the sun are, within an inch square area, about as parallel to one another as I could ever want, and yet I can look directly at the sun without worry of any damage to my eye. ---
**Author:** ![Oukile](https://avatars.discourse-cdn.com/v4/letter/o/13edae/32.png) [@Oukile](https://boards.straightdope.com/u/Oukile)\ **Post date:** [September 23, 2009, 6:59am UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/39 "2009-09-23T06:59:40Z")
> [@Sage\_Rat](#): > > But no, I doubt it would work. The issue is going to be with detecting the camera. The field of view that is blocked by an object drops off at an exponential rate as the distance is increased. At a quadratic rate, actually. > [@](#): > > Say that a paparazzi can shoot from a mile away (which seems to be accurate, though Google is being amazingly obtuse at stating viable camera ranges No paparazzi shoots from one mile, this is way too far ! If you want to shoot someone with, say, a 400mm lens, then 200-300 feet is about the maximum realistic range. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [September 23, 2009, 9:31am UTC](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049/40 "2009-09-23T09:31:02Z")
> [@Sage\_Rat](#): > > So you are saying that it is impossible to lower the light level of a laser to be of non-dangerous level? While I’m by no means a laser expert, I can’t think of any reason why that would be so. A laser is just a light source which lines up the photons to travel a parallel course. If I go out and stand on the planet Pluto, the photons coming from the sun are, within an inch square area, about as parallel to one another as I could ever want, and yet I can look directly at the sun without worry of any damage to my eye. Of course I am not saying that. A very LOW milliwatt laser is safe to the eye. The exact value is hard to say because it depends on so many things. But its still bright as hell. Blindingly bright actually. Unsafe means it actually cooks part of your eye/retina. There is a large range between “I can barely see it” to “burnt body parts” with a good range of "holy frack is that fracking bright, I can’t see anything!!! " in there somewhere. If ALL the photos that left the suns surface were headed directly towards you in a parallel fashion it would be BRIGHT. Not just sun in the sky bright (as seen from earth) but BRIGHT. And the important thing is, it would be the darn close to the same brightness whether you were at mercury or pluto or the nearest star (nitpickers can insert calculations here). If all that power was focused on a beam the size of your eye, it could probably recreate the conditions shortly after the big bang. If just all the suns light that currently reflects off of Pluto could be made parallel in a beam the size of your eye, it would probably be a scarily strong laser. Like cut battleships and death stars in half like a light saber strong (anybody care to do the calculation?). Its not just that the laser light is parallel. It that it STARTS off parallel, and in a relatively small area/cross section, and stays that way. It speads slowly due to diffraction, but thats another topic. Your example makes my point about the brightness of lasers. Even at Earth’s distance, the light from the sun is decently parallel. But, I can take a quick glance at the sun without damaging my eyes. I could even stare at it if I needed to look at it or something near it also bright enough to see. This would damage my retina, but it would take more than an instant. This is how people hurt themselves during solar eclipses. The light is bright, but you CAN look directly at it, if you are ignorant and unfortunate enough to do so. If you theorectically accidently shine even a few milliwatt laser in your eye, it would be surprisingly unpleasant. So much so, you would have a damn hard time IMO continueing to do it on purpose, and maybe doing permanent damage in the process. A camera has the exact same problem. The level may not be high enough to cause physical damage, but it can easily be high enough to really mess up/swamp the normal optical signal it is trying to record. [Previous page](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049.md?page=1) [Next page](https://boards.straightdope.com/t/could-this-work-anti-photographer-laser-shield/511049.md?page=3)