Do camera detectors really work? Is there a way to check it?

Recently, there have been many news reports about hidden cameras and micro cameras. The hiding methods are even more shocking. Not only is it said that 80% of hotels have them, but even the changing rooms in shopping malls are not immune to them. For a time, people were in a panic. Qiu Zhenjun, who still lives in a rental house, couldn't help but carefully search at home for a long time to see if his life had become someone else's porn film (luckily, he didn't find any).

After reading the news, I found that today's voyeurists are despicable and sophisticated. Not only do they hide the cameras very secretly, they can even control them remotely via WiFi , making it impossible to guard against them.

▲Integrated into home appliances, only experts can detect it with the naked eye

The reporter decided to buy it and study it! Knowing yourself and the enemy will ensure victory in every battle. It may be because the news about cameras is very popular recently. I searched the Internet but could not find relevant purchase information. "Pinhole" and "Secret Camera" must be blocked. So I tried "WeChat Camera".

There are indeed quite a few, and some have more than 20,000 reviews, so the sales volume is at least hundreds of thousands. In comparison, Qiuzhenjun chose a mini camera that supports WiFi control, and the express delivery arrived the next day.

In fact, it is a little different from the camera used for sneak shots in the fitting room. After all, in order to take sneak shots, the exposed size of the camera must be reduced in some way, leaving only about 1cm of the lens outside, and the battery, storage chip, etc. are placed separately and connected by a transmission line. Don't even think about buying this kind of camera online. I heard that they are all made offline. How does the one I bought online work?

This camera purchased online is not that small, but it is not too big either. It is even larger than a one-yuan coin. The reporter was attracted by the fact that this miniature camera not only can shoot wirelessly (up to 3 hours), but also supports remote live broadcast, so he quickly downloaded the APP to see the effect.

The reporter secretly raised the camera and looked around to shoot, and found that the guy next door did not notice that he was being secretly filmed. The picture marked 1080P is still very grainy, but the facial features of the person can be seen clearly when the indoor light is not very sufficient. Considering the small size and price, it is understandable.

The key APP also supports photo and video recording functions, and you can even watch the playback (TF card needs to be inserted), and you can remotely turn on and off the night vision function. It is almost comparable to those smart cameras used at home. The reporter couldn't help but be shocked. Such a fully functional miniature camera is installed in private locations such as hotels, rental houses, and fitting rooms, facing and recording the actions of different guests. Where these secretly photographed scenes will go, we have no way of knowing, let alone imagining.

The person who secretly photographs is in the dark, while the person being secretly photographed is in the light. Are we helpless in the face of these evildoers? No, the reporter learned that there are many devices for detecting pinhole hidden cameras on online shopping platforms, and the price is also between 200 and 300 yuan. Do these devices work? Qiuzhenjun purchased two of the best-selling ones to find out.

You may have seen many similar products on the Internet. Their functions are similar, which is to find pinhole cameras through high-brightness LED lights + wireless signal detection. So what are the specific effects?

To avoid interference, the reporter took a miniature camera and two detectors purchased online to the bathroom to try out this "spear and shield" contest.

Detector VS Micro Camera

According to the customer service, the multiple LED light rings on the back of the machine are turned on, and the red and blue lights flash alternately to emit light, which is reflected when it encounters the pinhole camera, thereby determining the location of the pinhole camera↓

Is that really possible?

The reporter looked at it for a long time, but didn't see much change. He could vaguely see a little reflection at the lens, which was not very obvious, and he had to adjust the angle to see it. Finding such a small spot in the room is as difficult as finding a needle in a haystack, and he didn't know where the criminals would hide.

Then let's try radio wave detection. The merchant claims that if there is a wireless camera device nearby, an alarm will be sounded. When Qiuzhenjun first got the two detectors, he also tried them in the office and found that the sensitivity of these two detectors was very difficult to control. Or perhaps there were too many wireless devices in the office, such as mobile phones and laptops that were using wireless networks, which interfered with the detectors.

So how does it work in a bathroom where there is basically no wireless equipment? I would like to say: It is quite useful.

It can be seen that when the detector is close to the camera, the detection indicator light will soar, and an alarm will sound (beep beep~) and vibrate, indicating that there is a wireless device nearby. However, the reporter found that the accuracy of this device is also limited. The animated picture shows that the second detector will also have a full signal reminder after leaving the camera. Such false alarms will also bring a lot of difficulties to our daily detection. If the hotel's WiFi strength is strong, or there are many wireless devices indoors, it will be even more troublesome to check.

So after our tests, we know that the camera detector can detect pinhole cameras to a certain extent, but it is also subject to many limitations. You may also consider buying one to give it a try. Remember to keep your mobile phone and computer away from it.

What’s more important to note is that this radio wave detection is only limited to those cameras that have WiFi remote control turned on. If the camera in the room is locally stored and does not have or has not turned on the wireless function, this detector will be helpless.

So besides buying a detector, are there any other ways to detect cameras?

1. Camera detection method (for night vision cameras)

Yes, there are! You may have seen on the Internet that you can use your phone's camera to find hidden cameras, because current night vision cameras illuminate by emitting infrared light that is invisible to the human eye, and most phones can capture this infrared light.

After turning on the night vision function, the reporter was able to capture infrared light with a OnePlus phone, which was even more obvious in a light-off environment. Then he tested some recently released mobile phones and found that except for the iPhone, all other phones could capture infrared light. Is Apple's camera a scumbag?

On the contrary, this is because the mobile phone camera's sensitivity to light is different from that of the human eye. The human eye can only see 380-780 visible light, while the mobile phone camera can sense infrared light and ultraviolet light, and is particularly sensitive to infrared light. Therefore, infrared light must be suppressed and high transmittance of visible light must be maintained, so that the mobile phone camera's sensitivity to light is close to that of the human eye, thereby making the captured image also conform to the eye's sensitivity.

Therefore, Apple's cameras are equipped with infrared cut-off filters as standard. This is to use precision optical coating technology to alternately coat optical films of high and low refractive index on the optical substrate to achieve high transmittance in the visible light region (400-630nm) and cut off near infrared (700-1100nm), which is used to eliminate the impact of infrared light on the imaging of mobile phone cameras. By adding infrared cut-off filters to the imaging system to block the infrared light that interferes with the imaging quality, the resulting image can be more in line with the optimal perception of the human eye.

Therefore, Apple's camera filters out infrared light in order to take pictures that are more in line with what the human eye sees, but it also causes the "embarrassing" situation of being unable to detect the night vision camera. It can be said that this was an unintentional success.

2. WiFi detection method (for wireless cameras)

In fact, mobile phones can also detect the signals of wireless cameras. The reporter would like to remind you that if you enter a hotel or homestay and find some long and garbled WiFi names in the WiFi list, it is very likely that there are cameras hidden in the room. These are generally the initial WiFi names of wireless devices. If you don’t have a detector, you can use some WiFi signal detection applications to find their traces.

The reporter recommends using the open source and free WiFiAnalyzer, which is very comprehensive in terms of functions. In the WiFi signal detection application interface, we can see that the mobile phone searches for various broadcast WiFi signals, and displays the approximate distance of the signal, signal name, and signal source WiFi chip provider. Based on the above information, we can roughly judge whether there is a camera with wireless transmission nearby.

For example, in the picture, there is an unknown WiFi at a distance of 0.2 m, so you should pay attention!

Summarize

Why have the number of hidden camera incidents increased in recent years? The reason is that the cost of electronic products has dropped due to technological progress, and the anonymity and convenience of online shopping platforms. When the reporter was writing this article, he saw another hot search: CCTV revealed that the pinhole cameras sold offline can already shoot 4K ultra-clear videos! This one in Qiuzhenjun's hand pales in comparison. I can't help but sigh that the criminals really racked their brains for lust and profit, and are more willing to "pile up materials" than mobile phone manufacturers.