After watching the concert, how many mobile phone cameras were "burned" by lasers?

Audit expert: Meng Meng

Associate Researcher, Institute of Physics, Chinese Academy of Sciences

The weather is bright and refreshing in autumn, and various concerts and stage activities are emerging one after another. For fans, the moving singing and wonderful performances on the scene are unforgettable. In order to retain these wonderful moments, many people prepare high-quality cameras or mobile phones with high camera performance in advance, hoping to record the wonderful moments of the performances by taking photos or videos.

Source: pixabay

At the same time, in order to protect copyright and the efforts of performers, many performances do not allow the audience to record videos for profit. In order to prevent illegal elements from secretly filming and protect copyright from infringement, some performances will use lasers to illuminate the scene before the performance to warn , or arrange staff to remind the audience not to take pictures.

Is it because lasers can damage video equipment that are used to warn people at events? To solve this mystery, we have to start with the concept of lasers.

What is the difference between laser light sources and everyday light sources?

The word "laser" was first translated by Academician Qian Xuesen from a foreign term, meaning a very strong light source. Qian Xuesen's translation method has been widely recognized and has been used ever since.

Laser diagram source: pixabay

The most common light in our lives is sunlight, which is a mixed light composed of multiple wavelengths of light . When sunlight shines on the earth, it has actually been attenuated in the atmosphere, so the intensity of sunlight shining on the earth is not that strong.

But lasers are different. Lasers can only output light waves of one color , and the color is very pure. The energy of lasers is very strong. Starting from the starting point, it will not stop if there is no obstruction during the transmission process. In addition, its directionality is clear, and the light source will not scatter during the propagation process, and the collimation is high. This results in a high light intensity in the area irradiated by the laser.

Laser source丨Wikipedia/Peng Jiajie

You may not believe it, but the brightness of lasers may be brighter than sunlight . If lasers are directly directed into the eyes, they may damage the retina, and if exposed to lasers for a long time, they may cause blindness.

Therefore, you must be careful when using lasers, especially not to let the laser shine into people's eyes, especially on children's toys. Children's eyes are not fully developed yet, and once exposed to strong light, it is very likely to affect eye development or even cause blindness.

Everyone knows that the human eye is fragile. Cameras are assembled from electrical components and are electronic mechanical products. They are not as fragile as the human eye. Why would a sturdy camera be damaged by lasers?

Why can lasers/strong light damage cameras?

The most popular digital cameras currently have built-in photosensitive elements . The photosensitive element converts the received light signal into an electrical signal that the camera can recognize, and then stores the electrical signal through analog circuits and digital circuits, and restores the electrical signal to an image on the screen through the signal input of the digital circuit. From this, it can be seen that the photosensitive element is the key to the imaging of digital cameras, but the photosensitive element has operating voltage and operating temperature limits. When the heat of the photosensitive element itself is too high, exceeding the upper limit of the operating temperature of the element, or the instantaneous voltage exceeds the limit, the element is likely to be broken down (i.e. damaged). When the photosensitive element is broken down, bad points, bright points or bad lines, bright lines will appear in the image of the camera.

What are some ways to avoid damaging the camera when shooting in strong light?

In addition to the possibility of damaging the lens of a mobile phone or camera when shooting at a performance, our lenses may also be damaged by laser irradiation in other scenarios. For example, night light shows, laser pens, etc. may all be the "culprits" that damage the lens.

Source: pixabay

How can you ensure the safety of your equipment and take beautiful photos and videos in a laser environment? Here are some shooting tips for you.

1. Pay attention to the shooting distance. Do not shoot too close to the laser. If you find that the device is very close to the laser, it is recommended to move the camera back and away from the laser irradiation range. This is why the cameras of audience friends in the backstage are more likely to be damaged during the concert, while the cameras of audience friends in the stands are not easily damaged by laser irradiation.

2. Pay attention to the shooting angle. Laser has a strong directionality. If the laser directly hits the photosensitive element of the camera, the photosensitive element is likely to be damaged; but if the laser hits the lens at an angle, the damage to the photosensitive element may be reduced.

Source: pixabay

3. Do not expose the lens device to laser irradiation for a long time. If the laser beam is directly exposed to the mobile phone camera for a long time, the mobile phone may be damaged even if it is far away from the laser light source. Because after a long period of exposure, the laser beam accumulates heat on the sensitive elements of the camera. When the heat accumulation exceeds a certain level and exceeds the heating degree of the photosensitive element, the photosensitive element will be damaged.

Knowing the characteristics of lasers, we should pay more attention in our daily lives. Do not let the laser directly shine on the lens equipment in the laser or strong light environment, let alone directly on the human eye. After all, if the equipment breaks down, it is only a loss of property. If it really causes irreversible damage to the eyes, it will be too late to regret.