Spy camera detection using smartphone time-of-flight sensors

Hey! Sriram here, author of this work. I&#x27;d be glad to answer any questions. There&#x27;s also a short talk I gave about this here (<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=t4Txdhlji4k" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=t4Txdhlji4k</a>) if that&#x27;s helpful!

&quot;Specifically, the hidden camera [...] reflects the incoming laser pulses at a higher intensity than its surroundings due to an effect called lens-sensor retro-reflection. This occurs when almost all light energy impacting an object is reflected directly back to the source&quot;

Here&#x27;s a demo video [0] of the app. It is embedded in the author&#x27;s website [1]<p>[0] <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=AFjGQNaqmXA" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=AFjGQNaqmXA</a><p>[1] <a href="https:&#x2F;&#x2F;sriramsami.com&#x2F;research&#x2F;" rel="nofollow">https:&#x2F;&#x2F;sriramsami.com&#x2F;research&#x2F;</a>

This reminds me in a way of the yacht with a system that detects cameras taking a picture of the yacht and sends a beam towards the camera to wash out the image.<p><a href="https:&#x2F;&#x2F;petapixel.com&#x2F;2012&#x2F;10&#x2F;28&#x2F;worlds-largest-private-yacht-features-a-laser-based-anti-photo-shield&#x2F;" rel="nofollow">https:&#x2F;&#x2F;petapixel.com&#x2F;2012&#x2F;10&#x2F;28&#x2F;worlds-largest-private-yach...</a>

Molka is&#x2F;was a problem in Korea. I wonder how it compares to SpyFinder Pro which seems like it&#x27;s 95%+.<p><a href="https:&#x2F;&#x2F;www.kickstarter.com&#x2F;projects&#x2F;spyassociates&#x2F;spyfinder-pro-hidden-camera-detector-spying-preven" rel="nofollow">https:&#x2F;&#x2F;www.kickstarter.com&#x2F;projects&#x2F;spyassociates&#x2F;spyfinder...</a>

&gt; system that leverages the time-of-flight (ToF) sensor on commodity smartphones<p>I think only the high end iPhones&#x2F;iPad have these type of cameras right now right?<p>I&#x27;d also be curious about the exact angle you have to hit to get a reflection<p>Probably wouldn&#x27;t work but bright flash in a room?

So, could this be used to find better hiding spots for hidden cameras?

I was working on a project like this and we relied on the fact that the IR filter on most cameras was a retro reflector. Remove the IR filter and the camera will be harder to find. I think the technique here also depends on the IR filter’s characteristics.

If there was literally ANY metric I would want in a HUD; &#x27;How many cameras are viewing me now, and where are they&#x27; has got to be the top of the list...

<p><pre><code> A stand-alone Single-Point LIDAR might be used to remove the high-end phone requirement. Should interface to a phone USB port with a simple UART&#x2F;I2C-USB adapter. Search Amazon.com for LIDAR finds &#x27;Lidar Range Finder Sensor Module TF-Luna, Single-Point Micro Ranging Module 0.2 to 8m Compatible with Pixhawk, Arduino and Rasppbarry Pi with UART &#x2F; I2C Communication Interface&#x27; $25. And &#x27;MakerFocus TFmini-s Micro Lidar Module 0.1-12M Lidar Range Finder Sensor Obstacle Avoidance Sensor Tiny Module 1000Hz Single Point UART I2C IO Compatible with Pixhawk Ar duino and Raspberry Pi&#x27; $39. The 2nd one is waterproof.</code></pre>

I would be curious to know what would be the best method&#x2F;tool to detect hidden cameras in places you visit (e.g. hotels, AirBnBs). I looked for devices on Amazon.com and found nothing that seems to be really good at detection.

Played around with this idea using the ToF sensor on my galaxy note 10+ and an app called &#x27;ToF Viewer&#x27;[1]<p><a href="https:&#x2F;&#x2F;imgur.com&#x2F;a&#x2F;XcEMxcZ" rel="nofollow">https:&#x2F;&#x2F;imgur.com&#x2F;a&#x2F;XcEMxcZ</a><p>Camera array of a thinkpad T480 with windows hello (ir camera) and a hazard light&#x2F;strobe (sourced... locally)<p>[1] <a href="https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.lvonasek.tofviewer&amp;hl=en_US&amp;gl=US" rel="nofollow">https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.lvonasek.t...</a>

I wonder how hard it would be to engineer a material that you can put on top of the hidden camera lens that would greatly diffuse the specific frequency range of light that these ToF sensors use while permitting mostly visible light through? If so, it might be possible to defeat this approach relatively easily.<p>Looking at what the DL filter is doing, I wonder how well this really generalizes. It seems that many of those examples are virtually indistinguishable to a human (hence the high false positive rate for the naked eye experiments).

If the spy camera has infrared leds then you can detect those by removing the infrared filter from a camera, can be done on some smartphone cameras programmatically I think.

It hard to tell if these modules contained IR interference filters, some of the part numbers are only for sensors not modules. If they have interference filters I could see that there would be a strong IR reflection. It would be interesting to see the results with a absorptive filter, although I am guessing real spy cameras have no filter at all. Improve the sensitivity vs making a pretty picture.

I&#x27;m having a hard time seeing how the obsolete and not exactly tiny OV2640 was crammed into that electrical plug. The integrated module is a 10mm cube with a 1&#x2F;4&quot; lens and to be useful it needs a power supply and either a storage controller or wireless network interface.

&quot;Tiny hidden spy cameras concealed in sensitive locations including hotels and bathrooms are becoming a significant threat worldwide.&quot; I think motel room tenting and indoor foil-wearing might seem to be more justifiable, less paranoiac. Who knew?

I was really hoping that they had an app I could install, as they implemented LAPD on Android.

Does the app take pictures to find the lens? Or videos?

Can you overwhelm this detector by hiding the camera in another reflective material (eg wrinkled metal or shards of glass wall decor)

Could someone please help explain the threat? Are people being blackmailed with footage obtained of them? Is this occurring en masse?

The site is unusable if you have cookies disabled. It does not let you read the content of any page.

The expansion&#x2F;collapsing of the header on that page seems to get in the way when scrolling up.

What I would like to know is - how do you detect who is using an IR blaster?

What are the best ways of doing this without a smartphone?

Lenless camera, the latest next research rage?

similar technology exists on ebay for under $5, you plug it into the phone&#x27;s usb port and it emits ir led lighting and back into a lens

Did the Rubidium price go up already ? ;-)

Clever! Thanks :)

fdsd

I know a woman who discovered a hidden camera in the female toilet at work disguised as some kind of utility hook on the door. Cheap to buy on amazon!! The SD card inside had pictures of the company owner&#x27;s desk but not an actual picture of him. The police declined to prosecute because of lack of evidence.

It took me a full minute to realize this wasn&#x27;t the Los Angeles Police Department&#x27;s R&amp;D division

The acronym should be removed from the HN title. LAPD does nothing but sow confusion when used as the first word here.

LAPD is not the Los Angeles Police Department, despite what we all were thinking.

It&#x27;s interesting with these wrap head lamps, which have 40 COB(Chip on Board) LEDs, is you see spiders everywhere at night. And other large animal eyes with a Tapetum lucidum look &#x27;strange&#x27;, not like normal led reflections.<p>It&#x27;s a bit unnerving&#x2F;cool that you&#x27;ll see 10 pairs of eyes looking back from the lawn you might have just been lying on.<p><a href="https:&#x2F;&#x2F;www.amazon.com&#x2F;Headlight-Rechargeable-210%C2%B0Illumination-Headlights-Lightweight&#x2F;dp&#x2F;B09579W64H&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.amazon.com&#x2F;Headlight-Rechargeable-210%C2%B0Illum...</a><p>I&#x27;d be looking at something like that, at least as a first run over the room. But perhaps to augment. It allows you to see spider eyes at 5+ meters.

You have to go to the second page of the full PDF to even see what LAPD stands for, which is Laser-Assisted Photography Detection. They need to be more mindful of this, especially when they made up the acronym themselves.