5 ms·
A way easier solution to this is to turn off all of the lights and look around with your phone camera. The phone camera will pick up the bright IR lights that
by declan_roberts 2y ago
A way easier solution to this is to turn off all of the lights and look around with your phone camera.
The phone camera will pick up the bright IR lights that hidden cameras use to illuminate the room-- wireless or not.
Obviously this only works if the camera uses IR lights, but pretty much all of the sneaky ones do.
- RamboRogers 2y agoWell, maybe - it would need to have ir enabled. This also detects listening devices etc.
- mbreese 2y agoWould this also be able to detect something like a camera that saves videos to an SD card to be retrieved later? Something that doesn't use WiFi or a radio? That's the main limit I see, but I'm wasn't sure if it such a device would still generate enough RF intrinsically w/o a radio.
- ddingus 2y agoMaybe those could be found with a parabolic antenna and possibly an amp, ideally one with a limited range one can control via software. Once a few common signals are known, the software could do programmed patterns to ferret out easy ones.
- Ballas 2y agoMost phone cameras have pretty steep IR cut filters these days. The front camera on most phones still don't, so you have to use that. That said, most of these spy cameras don't have IR illuminators...
- deknos 2y agodo you have examples of cameras or smartphone which do not have IR filters?
- Ballas 2y agoI don't but it's easy to test, just pick up a TV remote and press a button while pointing it towards the camera. It should look like a flashing white LED. I should also mention that both IR illuminators and TV remotes are usually either 850nm or 940nm, I have not looked into that aspect of it. I imagine that it's possible that your camera can detect one but not the other...
- ddingus 2y agoMy phone goes up to 980nm and it is a Note 9. Both front and rear cameras work. The light shows up as a pinkish purple.
- botanical76 2y agoThanks, I had no idea about this. My Google Pixel 8a doesn't show anything on either camera, but my friend's front camera did! It shows up light purple.
- karlkloss 2y agoRaspberry Pi sells a camera especially without IR filter.
- amatecha 2y agoFor anyone curious, that would be the "NoIR" camera: https://www.raspberrypi.com/products/pi-noir-camera-v2/ https://www.raspberrypi.com/products/pi-noir-camera-v2/
- lightedman 2y agoEasy test - check your black levels against someone wearing a black fabric or a reflective black surface. If you get a fair bit of grey in the image, odds are very great that you don't have an IR filter installed.
- runjake 2y agoLies. :-) Somewhere in my HN comment history from a while back is a response to a person claiming that modern phone cameras can’t detect IR illumination and remotes. I took a bunch of modern iPhones and Android phones, from colleagues in an IT dept, and demonstrated they can in fact see a bunch of different IR remotes and illuminators with the rear camera. I could find zero cameras that could not see the IR. I’m not sure where people got the notion they couldn’t.
- JKCalhoun 2y agoGuessing because they read that CCD's have IR filters on them.
- runjake 2y agoUpdate: here's the comment: https://news.ycombinator.com/item?id=40513967 https://news.ycombinator.com/item?id=40513967
- pwg 2y agoThe ultimate answer is "it depends". And upon what it depends is the particular IR wavelength the camera emits to "illuminate" a scene in IR for night photography. My cell phone's back camera will show IR light from IR remote controls (I've used it for just that to verify that a remote is transmitting). But I also have an outdoor IP camera with IR illumination in my back yard. The same cell phone camera sees zero IR emitted from the outdoor IP camera (even though it quite well lights up a fairly broad area of the yard at night). So for my phone, if a 'spy cam' were using the IR wavelength the IP camera uses, I would never know it was present by using the phone camera. If it used something closer to the wavelength used by IR remotes, yes, then the 'spy cam' would light up via the phone camera.
- lightedman 2y ago"I’m not sure where people got the notion they couldn’t." I make IR devices. My phone is the only one in the warehouse that can pick up their emissions - everyone else's cameras have IR filters with what appears to be a sharp ~750nm cutoff. I'm the only one that will pick up 800-1064nm with my cheap Samsung, and so I'm the only one doing the testing on those diode assemblies.
- alwayslikethis 2y agoMost of the bright IR lights you find on typical surveillance cameras actually visibly look a little red. I wouldn't think the same lights would be used if the intention is to spy in secret.
- declan_roberts 2y agoThat's exactly right, and part of that is because they're cheap and put off some visible light. Thankfully the perverts who put this stuff in airbnbs just go to amazon and search and buy cheap stuff, which is easy to detect.
- kube-system 2y agoThe lower wavelengths like 850nm IR LEDs are visible. Some cameras use higher wavelengths like 940nm IR LEDs and they aren't.