Hidden Camera Detection

Hidden Camera
  Reading time 8 minutes

Hidden Camera Detection

I did a ton of research into smartphone apps to see if any of these so-called detectors for hidden cameras actually did anything and surprise, the results are not very promising.  I figured that since almost everyone has a smartphone, if one of these apps actually worked, then it would be a free or low-cost method to accurately detect these hidden cameras.

The Test

I had four wireless cameras that I used for this test.

Camera #1

A round little “spy camera” from Amazon (https://www.amazon.com/Camera-Hidden-Camera-Wireless-Camera-Cameras-Outdoor/dp/B09NR7FT7D/). It is a 1080p HD camera operating on the 2.4Ghz wireless spectrum as well as saving to the micro TF SD card

Spy Camera

Camera #2

A tiny square “mini spy camera” from Amazon (https://www.amazon.com/gp/product/B09N95FLXH/). It is a 1080p HD camera operating on the 2.4Ghz wireless spectrum as well as saving to the micro TF SD card

Wireless Camera Mini Hidden Spy Camera Portable Small Nanny Cam Features with Body Pet HD 1080P Camera, Night Vision and Motion Detection for Home Outdoor Office.

Camera #3

A “Security camera outdoor” from Amazon (https://www.amazon.com/gp/product/B08DY9YGYJ/). It is 1080p and operates on the 2.4Ghz wireless spectrum as well as saving to the micro TF SD card

Security Camera Wireless Outdoor, 1080P HD Rechargeable Battery Powered Home Security Cam Smart Surveillance WiFi Camera with IP65 Waterproof, Night Vision, Motion Detection, 2-Way Audio, SD Storage

Camera #4

A built-in camera in my older Samsung Note8 phone (the rear camera for this experiment)

Samsung Galaxy Note 8, 64GB, Midnight Black - Fully Unlocked

Since there isn’t a valid rating system per se at the Google Play store (beyond the star reviews, which are mostly fake), I downloaded the apps with the highest star ratings and went from there. There are some websites that “rate” these apps, but they are obviously either paid to do so or they are the vendors themselves as the reviews they give are very slanted.

My test device is a Samsung Galaxy S20 running Android 12

The Technology
There are several different methods these apps use to find hidden cameras:

Glint of the lens or the image sensor – The glint from a camera lens, is nothing more than the reflective lights from the camera lens. Sometimes you might even be able to capture a reflection from the image sensor (depending on the type of image sensor) instead of the lens, depending on how the camera is set up and if there is a physical shutter. The apps will often change the color of the screen in the hopes of making it easier to detect these glints or reflections.

Radio Frequency – Since most of these cameras are using wireless data signals at 2.4Ghz (using the 802.11 standard) or Bluetooth which is in the 2.45Ghz range, they would be emitting a signal at those frequencies that is detectable. A scanner app claims to be able to find those data signals but uses the phone’s built-in radios to detect both WiFi and Bluetooth signals.

Magnetic Field – Most modern smartphones have a magnetic sensor, that is used to help apps like a digital compass function. However, you can use that to determine how strong or weak a magnetic field is. Since the cameras are electronic and any kind of electronic device emits electromagnetic radiation at various frequencies which depend on the design, this EMF radiation would be in the VLF frequency (3–30 kHz) range. The app doesn’t actually detect the frequency, it deletes the magnetic field itself. The apps will detect the field in uT or microtesla. The stronger the field the closer you are to the device emitting the field (or the camera in this case)

The Apps
I tested eight apps for Android from the Google Play store.

  • Hidden Camera Detector (by futureapps)
  • Hidden Camera Detector (By The Hidden)
  • Spy Camera Detector App (by High Quality KK Developers)
  • Detectify – Detect Hidden Devices (by WonderTech Studio)
  • Hidden Camera Detector, Finder (by Cyper Apps)
  • Hidden Camera Detector – Spy Camera Finder (by Digital Apps and Games)
  • Hidden Camera Detector (by Sifie Apps)
  • Hidden Devices Detector (by Zaib Soft)

Hidden Camera Detector (by futureapps)
First up was Hidden Camera Detector by futureapps (free version), there wasn’t much that was not locked out. You had four major options, which are Detect Wired Camera, Detect Infrared Camera, Detect Wireless Camera, and Lens Detector. The Detect Wired Camera and Detect Infrared Camera functions are unlocked, and to be honest, didn’t do anything impressive.

The “Wired Camera” option, pretty much detected anything electronic. The “Detect Infrared Camera“, is in my opinion more of a gimmick than a real function. They all work the same, they change the screen green, in an attempt to see a “glint” from the camera lens and some try to catch the IR signal from the infrared camera (which usually operates in the Thz range – Just below the visible spectrum).

The problem is they just don’t really work. However, this app does allow you to change the way the app looks for the lights, so I thought it might be promising. I do want to note that I was able to see the lenses at a distance of about 18″, which is pretty much useless when scanning a room for a camera. I’m sure that with some patience and practice, you could extend that range, but it just isn’t very practical to look at the entire room 18″ away from the walls.

I would have to say that much of this app is just a gimmick and really doesn’t work as I had hoped, There are ads just about everywhere and some are back-to-back, which is extremely annoying. Generally, apps that do that are just trying to make revenue off of people like me, who are going to try it and remove it, but they just got 5-6 ad impressions.

The theory here is that the wireless will hope to scan for a rouge RF signal between the router and the camera. However, you have to know what you are looking at in order to catch it.

The magnetometer is looking for metal or a magnetic field. The problem with that is nails, pipes, and metal studs. If it detects a magnetic field, you would need to be really close to the source in order to detect it.

This app has 3.8 stars, over 24,000 reviews, and over 5 million downloads. It seems the higher ratings are either for a different product, or the user just doesn’t understand. One even states that it detected good at 6 inches away from the camera.

If you go to a hotel and you scan the room, you want to be able to stand in the middle and scan the room, not taking your cell phone and moving your phone up and down each wall at a distance of 4-6 inches from the wall. It is only going to be effective if you already have a hotspot or two in mind.

Hidden Camera Detector (by futureapps) in the Google Play Store

Hidden Camera Detector by futureapps
Hidden Camera Detector home screen
Hidden Camera Detector by futureapps
Hidden Camera Detector looking for a "hidden" camera
Hidden Camera Detector by futureapps
Hidden Camera Detector User Consent Screen
Hidden Camera Detector by futureapps
Hidden Camera Detector searching RF or Magnetic Field for a hidden camera
Hidden Camera Detector by futureapps
Hidden Camera Detector by futureapps looking directly at a camera

Up next will be Hidden Camera Detector (By The Hidden)

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