There are a lot of hidden camera detector apps available on the market; These apps use several methods to detect spy cameras though they do not necessarily work for all types of cameras.
Hidden camera detector apps can work for any spy camera that uses infrared lights or Wifi signals but not radio frequency. Such apps will function under specific conditions (i.e., not low distance, different angles, and low lighting).
I'll go into further detail below.
When Does a Hidden Camera Detection App Work? (Camera Types Examined)
All spy cameras emit either light, WiFi signals, or magnetic activity. An app that detects cameras can spot these emissions.
The detector sends light from your phone's torch light to the room. Then, it shows you any possible reflection of that light. Every reflection could be a spy camera.
Note that for the app to detect hidden cameras, the light projected shouldn't be further than 3-5 feet (91.44-152.4 centimeters).
2. Infrared/Night Vision Cameras - Works
These types of cameras release Infrared Light (IR light).
The IR light can be visible to a camera but not to the human eye. Thus, a camera detection app will work best in this case.
Through your phone's camera, you will see white or blue lights where a device gives off IR light.
3. Wireless Cameras - Works
If you find a camera hidden in a room, it will most likely be wireless.
Wireless cameras need to be connected to a device through Bluetooth or WiFi. Hidden camera detection apps have a function that detects WiFi signals that derive specifically from wireless cameras.
Sometimes it might be hard for the app to find the signal from a camera because there might be many surrounding networks.
4. Wired Cameras - Works
Although not that common nowadays, a camera can be wired and spotted by a detection app.
These cameras discharge magnetic activity that can be discovered by an app using your phone's magnetic sensor. The app will beep and show you a "Warning" sign.
Note that such an app may mistakenly show you warnings for the television or the microwave oven, devices that emit magnetic activity.
When Does a Hidden Camera Detection App Not Work?
Radiofrequency cameras, equipment that uses IP addresses to activate and deactivate a camera, and certain conditions (i.e., distance, angle, lighting) are the cases when a hidden camera detection app will not work.
1. Radio Frequency Spy Cameras - Don't Work
There is a type of camera that uses radio frequencies. Mobile phone cameras cannot detect such frequency rays.