The sneak shot is rampant, is the camera detection App really reliable? What other test methods are there?

Although the vicious incidents photographed by cameras in hotels and homestays have been exposed many times, it seems that this trend has not been curbed, and the videos photographed by cameras are still emerging one after another. At present, many apps have introduced the camera detection function, which is convenient for people to find out whether there is a hidden camera with their mobile phones.

According to the introduction of the APP, they used infrared light detection, reflected light detection, Wifi hotspot detection, magnetic flux detection and other means to detect the camera. Are these app detection cameras reliable? Let's talk about it

Infrared light detection

Reliability: ★★★☆☆☆

Many cameras have the function of imaging at night, or it may be because these cameras have infrared imaging systems. This camera module emits infrared light invisible to the naked eye. After reflection, the infrared light will be imaged by the photosensitive element-although the infrared light is invisible to the human eye, the photosensitive element in the camera module can. Therefore, this camera realizes night vision.

Some cameras realize night vision by actively emitting infrared light.

Using this principle, the mobile app can indeed detect such a camera. APP can call the photosensitive element of the mobile phone to see if there is a suspicious infrared light source in the darkroom. However, this method also has limitations.

Cameras that sneak shots must emit infrared light. Not all candid cameras rely on infrared light to achieve night vision, and some rely on high sensitivity and large aperture to image in low light.

The photosensitive element of a mobile phone must be able to sense infrared light. In order to get better imaging effect, some mobile phones have installed infrared filters and other filtering devices in front of the photosensitive elements to reduce the interference to visible light imaging-but in this way, mobile phones can't perceive infrared light, and they can't find infrared night vision cameras.

How to judge whether the mobile phone can sense infrared light? You can turn on the camera APP in low light, aim the infrared emission sources of some home appliances remote controllers at the lens of the mobile phone, and press the remote control button to see if there is light in the viewfinder. If not, it means that the mobile phone can't perceive infrared light, and the camera that APP detects infrared imaging is out of the question.

Reflected light detection

Reliability: ★★★☆☆☆

This is a detection that depends on the light reflected by the lens. Generally speaking, cameras will be coated more or less to reduce direct light at certain angles and prevent imaging interference factors such as glare and ghost. Because of this, for some angles of light, the lens will have a stronger reflection, so the APP can use the flash and camera of the mobile phone to illuminate a specific position, and detect whether there is a hidden camera around by whether there is abnormal reflection.

The lens coating will have a strong reflection at a specific angle (the picture is not a camera shot, just a gesture)

This detection method is reliable in principle, but it obviously has limitations.

The flash light has a small irradiation range and can't take care of the whole house. Mobile phone flash is not a high-power light-emitting element. Only when there is a strong light source in the central area and close illumination is needed can the hidden camera generate enough reflection, so it takes a long time to inspect the whole room.

The lighting angle is not necessarily the best, which requires patient investigation and careful observation. The lens coating will strongly reflect light at a specific angle. If the camera is hidden deep, such as hiding the hole of the smoke alarm, there may be no suitable reflection angle.

Easily disturbed by other reflective objects.

In short, for most cameras, applications can really use the glare of the flash to detect them. But this is more about manual operation and the probability of leakage is higher. It is recommended to keep the house price in a dark state when using the reflected light detection camera, so that it is easier to see the clue.

WiFi detection

Reliability: ★★★☆☆☆

This is a function that many camera detection apps have at present, and even some security housekeeper apps have added similar modules. The principle of using Wifi to detect cameras is because many cameras will transmit data through the Wifi network. After the mobile phone is connected to the Wifi network, it can detect whether there are suspicious devices in the Wifi network.

Many security apps have the function of using WiFi to detect cameras.

At present, some security apps use the camera feature code identification database, which can detect whether there is a camera in the access device in the Wifi network. In principle, it really works. If the camera is connected to Wifi, it is difficult to escape the eyes of the APP.

However, this method also has limitations. Not all cameras are connected to Wifi. Some cameras use local storage such as SD cards to store videos, while others are equipped with SIM cards to transmit data through mobile networks. In this case, the APP can only detect the camera through Wifi, and it fails.

Magnetic flux detection

Reliability: ★☆☆☆☆☆.

This is also a common means for APP to detect cameras. Its principle is this: most mobile phones have magnetic flux sensors, which can detect ferromagnetic substances. So use your cell phone to get close to the suspected camera. If the magnetic flux fluctuates, there may be cameras here.

It is not very reliable to detect the camera with magnetic field.

Is this method reliable? Obviously, many times, it is unreliable. A camera is not necessarily magnetic enough. On the contrary, the electromagnetic components in many ironware and household appliances will induce fluctuations in the magnetic flux sensor of mobile phones.

Of course, if the hidden position of the camera has been roughly determined by other methods, it is not bad to further confirm it by this method.

abstract

It can be seen that although many apps have the function of detecting hidden cameras, there is still no 100% reliable solution today. If the camera does not emit infrared light, the hidden reflection of the position is not obvious, there is no Wifi network, and there is no magnetism, so it is difficult to detect it with APP. In the face of the increasing proliferation of candid shots, everyone still needs to be vigilant. If you find anything unusual, call the police immediately to effectively protect your rights and interests!

Not reliable, the best detection method is to use the tools in Carrier system, not to mention the specific tools, to detect the router to see the port of access to the network.