How to check the pinhole invisible camera

In dim light, the video recording function of the mobile phone can detect the pinhole camera when the infrared light is turned on.

However, using the mobile phone camera to check the pinhole camera mainly depends on whether the camera has an infrared compensator. The real pinhole camera has no infrared compensator, only a wide-angle fisheye lens is exposed, and the back is imaged by CMOS. It is an optical receiving device that does not emit infrared rays. It is not feasible to find the red dot with a mobile phone.

So it is recommended to use professional anti-reconnaissance equipment. One is to detect the frequency leakage of the camera circuit and the radio frequency that emits wireless signals, which belongs to the radio detection method; The second is to use the particularity of fisheye lens to reflect the light to the wall, and use optical equipment to receive and display its reflection. Because the reflection path of pinhole camera with fisheye lens is different from that of general wall or mirror, it can be marked.

special technology

The principle of various pinhole cameras is similar. They project the light collected through the lens onto the photosensitive element, which converts the light signal into an electrical signal; Converting the electric signal into a digital signal; The digital signal is compressed and transmitted to a monitor or recording device, so that it can be displayed or recorded as an image that we can see.

Due to the limitation of volume, this kind of camera generally does not have too complicated functions, nor can it adjust the focal length or aperture. They are generally composed of lens, image sensor, A/D converter, image controller, etc. If there is audio function, components for sound collection, processing and transmission will be added.