For travelers’ (in)peace of mind, the popularization of informal accommodations managed through platforms such as AirBnB has allowed the cheapening of tourism but also the roguery (if not outright criminal behavior) consisting of hiding tiny cameras in the accommodations.
Infrared light is invisible to the human eye but it can be detected by a smartphone camera sensor
With them the hosts achieve intimate recordings of the guestseither for personal enjoyment or so that they end up circulating on the Internet showing essentially the moments when unsuspecting travelers have sex without knowing they are being recorded.
Without resorting to sophisticated equipment for detecting systems more typical of espionage films, anyone who fears being a potential victim of these hidden cameras can be reassured thanks to something that for years practically the entire population has been carrying with them: the cell phone. All thanks to the fact that these hidden cameras are usually equipped with infrared technology, capable of capturing images in the dark. A type of light that is invisible to the human eye, but capable of being detected by the sensor of a smartphone camera..
Depending on the smartphone model there are some in which only the front camera is able to detect infrared emissions, in others both cameras (front and rear/back) are capable. To check it the method is quite simple because also at this point in practically every home there are an infrared emitting device: the remote control of the TV set.
The following is going to detail the method to detect by means of the cell phone camera the infrared emission:
-Activate the cell phone camera.
-Focus towards the part of the remote control that has the infrared signal emitter (sometimes a small emitter of a very faint light can be distinguished).
-Turn off the lights in the room (and/or draw the blinds/curtains if necessary) to make it as dark as possible.
-Press buttons on the remote control.
The mobile display should clearly show the infrared light beam emitted by the remote control when the buttons are pressed.
Once you already know how to detect this type of emission for the case of being in a room where you may have the suspicion that there are hidden cameras (that yes, only if they use infrared technology) the method to detect them would be similar:
-Darken the room.
-Route the room pointing with the cell phone camera activated.
Another method of detection would be through WiFi for cameras that use this technology to transmit the captured images to other remote equipment. Here it would be necessary to install on the cell phone apps like Fing (available for iOS and Android) that are able to detect devices that are connected to a WiFi network.
The usual in tourist accommodations is that there may be available a wireless network and unless the host has gone ahead and set up two WiFi networks, one for guest use and one reserved for their wireless cameras, they are usually all connected to the same wireless network. It would be enough to run one of these applications that would report if any WiFi camera is connected.
Finally, and already in the most suspicious chapter or for spies, would be the radio frequency detector devices, which would allow to find both cameras and microphones that use this type of signal to transmit sound and / or images. But this, unfortunately, exceeds the capabilities of a smartphone.