this article is actually just an advertisement for this product. https://www.senteltechsecurity.com/lawmate-dd802-defender.ht...
Yes, the article mentions a product from the company, not in a sneaky way. The rest of it, some 2,800 words, is interesting and informative--to me, at least.
An article can be both informative and self-serving, and there's nothing wrong with that, provided there's no deception. Most of what you read online is self-serving, in some way.
First of all, your caveat does not hold. This article is deceptive in full. None of the advice presented here is good at all... "divide the room into quadrants and search each quadrant"? Why? Just search the entire room. The article fundamentally gives the impression that you will not actually be able to locate any spygear unless you have an RF detector and a camera beacon simply by not giving any good advice otherwise. "Check if the outlet covers have been changed?" right, because when I bug a house that I own, I also buy a new outlet cover.
No one trying to sell you something is going to tell you how you could effectively live your life without their product. This is fundamentally deceptive, and seems to have gone so far as to have fooled even you.
The article answers that:
Splitting the room into sections will help you to systematically and meticulously go through the room and clear each section without skipping over any of the fine details.
This strategy is generally known as “divide and conquer”.
In military parlance, it means that you have a much greater advantage against 2 armies of half size separately than against them both simultaneously. This is known as Lanchester's law, and the whole point is that it's non-linear.
In algorithms, the idea is roughly that, given a method which solves a problem, it is often cheaper to split your input, solve each half, then merge them, than it is to run the algorithm on the entire input. Again, non-linear.
Dividing your room into quadrants provides NO advantage to searching your room. You still have to search each unit area methodically.
And surgeons were pretty sure they'd never leave an implement inside a patient, but the stats still improved with the introduction of checklists. Like checklists, the quadrant method means there's less demand on your memory, which means less chance of forgetting things if something unexpected happens.
This is a difference between content marketing and actually caring about informing the reader.
I bought a house that had a slight dimple in the heating duct of a ground-level bathroom, mostly concealed by the vent cover. I went down into the basement, and surely enough, from a certain spot, I had a clear view of the toilet and shower from below. I bent the duct back flush with the edge of the hole, and concluded that was probably one of the reasons that the sellers were getting divorced. So you might not find a camera. There might be an actual eyeball there sometimes. An electronic scanner isn't going to find that.
I'm pretty sure most us techies have a pretty intuitive understanding of how to methodically build software yet we still see great benefits in breaking down projects into smaller tasks.
My point is the bigger picture often looks easy from the outset but in practice most people do benefit from dividing jobs up into smaller tasks or quadrants and focusing on each of those individually.
This whole business of dividing rooms into quadrants smells awfully lot like usual content marketing non-informative filler.
The origin of the "divide and conquer" idea, the "divide and rule", is also about non-linear effects. At least two can be named here: thresholding (ensure your opponents into groups small enough you can take any individual on directly), and Metcalfe's law (effect of a group grows with the square of number of fully-involved participants).
But can it be, really? Usually one of the two goals suffers badly.
The top 50% of this article reads like low-effort content marketing cookie-cutter nonsense, and I almost stop reading there. It got somewhat interesting towards the other half, true, but someone interested in informing people instead of pushing their product (and the need for their products) could easily shorten this article by 50+%.
This is interesting. Is that red filter-looking thing part of the mechanism for detecting lenses?
I'll say! That's really cool. Thanks for explaining how it works.
To detect the reflection from the sensor in the case of a real lensless pinhole camera you would have to be on the line perpendicular to the sensor through the hole, else the reflecting ray would not return through the pinhole.
If someone knows more about the supposed systems that actually detect fluorescence or the antireflective coating spectrum of the light sensor itself please please reply!
this immediately makes the setup less usefull for surveillance cameras as they will typically not be optimized for color fidelity, but for light sensitivity, so without IR filter...
Nevertheless I would still be interested in more details or the exact mechanism or references...
However it wouldn't detect those same night-vision cameras, since they are most often just standard webcam guts with that IR filter omitted as you say.. I really think this thing is just what it says--a lens detector, which catches specular glints off the glass lens and doesn't have much to do with the actual CCD or CMOS or whatever sensor is underneath. It could definitely be making use of the IR filter on most cameras to make those shine particularly bright.
I'm not sure how the cinema version works though, or might the IR filter be a dielectric high-pass filter (similar to how anti-reflective coatings work), passing red but reflecting near IR?
Optically in the near IR that would be equivalent to a mirror between sensor and lense, for simplicity lets pretend the filter is nearly in the same plane as the sensor in the focal plane, then parallel rays focused at infinity would converge to a point on the mirror, which means the light should retroreflect, but the intensity of retroreflection should be highest at the optical axis, and quickly fall off away rom the axis... that makes for 4 DOF to "scan" direction to aim the beam of light, and 2-dimensional position with respect to aperture... so you need to be either lucky or have a very good idea of typical orientation and position of the camera, which would also explain the usage in cinema's you know the orientation of the camera so now only 2d of freedomm left...
Probably way crappier, but for what these electronics entail the one sold by the website in the post is vastly overpriced. It's a very simple radio, a battery, some LEDs, and an optical filter of some kind. Likely just a red gel. Plus, how great of a bug detector do most people really need? The main features are all there and it's probably workable in most cases.
Disclaimer, I don't own this. It could be a mega-turd, don't buy it on my account.
The crowd here could probably build one of these out of whatever's in the junk drawer. Looks like it's the RX half of a cheap analogue walkie-talkie and some flashing lights. That's it. Two hundred bucks is egregious. Maybe if you were an actual LEO or a private eye, but for most people it makes absolutely no sense to buy the $200 version without first seeing if the $10 version does the job.
Well this is certainly subjective and dependent on multiple factors. It may very well be that you could get a similar device for $10-$20 or scrap one together for as much, but its probably not going to come with a good warranty or much reassurance of it's actual performance. And also, just as the crowd here is more likely to be able to build one, the crowd here is also more likely to be able to drop $200 on something if they want it.
Use cases matter. Someone worried about voyeurs should think like voyeurs. They're driven by impulse and most of the time are probably not going to be super organized or resourceful. There's no need to waste your money on RF detectors or camera lens detectors if you are dealing with the kind of hidden surveillance equipment you'd see on Amazon; it's not that sneaky and you can just examine objects like clocks, smoke alarms, door hooks, and phone chargers for obvious cameras. These kind of surveillance devices are really only hidden to people who aren't looking for them.
OTOH if it matters enough to want a camera lens or RF detector I'd definitely at least want a good piece of tool. Doesn't have to be the one in the article, but it'd certainly be worth considering. This is especially true in cases of potential corporate espionage and other situations of similar importance.
Not at all saying there isn't a market for a cheaper device or a DIY replacement, but to be honest I think a lot of people are better off with buying nothing, if you ask me.