Laser technology is increasingly used in presentations and performances, which is also the main cause of a series of camera sensors that died in one region or all over the past few years. If improperly used recording devices are used, these laser beams not only affect the device but can also harm the user’s eyes.
New Lunar New Year is also the festival season with many stages and big performances, I would like to send you an explanation of the mechanism as well as how to protect yourself and equipment before the light & death; Hey!
1. What is a laser?
LASER is abbreviated from L ight A mplification by S timulated E mission of R adiation means & quot; amplify stimulated light emission & quot ;, was invented around the early 1960s. Laser is essentially a beam of photons It is repeated several times to amplify the energy of the beam in a storage chamber, which is then projected out through a directional lens at the top for a parallel beam. Therefore, the laser beam will usually have very large power sources.
Since its invention, lasers have been applied in many fields: from scientific research to quantum or astronomy, to military or medical industries. Lasers are also easily caught everyday in print shops that engrave letters or in a pen that is shown when presenting. Of course, the intensity of these beams is classified for each purpose.
Laser is classified into 4 main categories according to energy and hazard from low to high. This is a classification since 1970, there is a new classification of 2002 that has not changed much apart from the addition of wave frequencies. Currently laser devices that are shown on the market mostly use the old standard. I summarized here as follows:
- Type I: The energy is weak and almost harmless, emitted through an optical projector, often used in the reading eye of a CD /DVD player.
- Type II: Provides visible light and is only harmful when looking directly at the source for a long time. Commonly used in measuring devices and some types of presentation board markers. This type is recommended not to look directly at the light source.
- Type IIa: Lower energy levels than Category II with longer projection times. Used in photocopiers or scanning documents.
- Type IIIa: For continuous lighting, it is recommended to use it carefully, its ability to cause eye damage is low, causing injury only when viewed directly at the source with time 2 minutes or more.
- Class IIIb: Large energy levels and continuous light, can cause damage to the human eye if viewed directly on the source in a short time. The scattering rays of this laser are not harmful. This type is often used in current laser projectors but is specifically designed to spread light to reduce the energy of the beam./li>
- Type IV: An industrial laser with very high energy that can burn skin and cause great harm. Often this type will be used with a special controller and a safety lock as well as the need to wear goggles when operating. Class IV lasers are often used in industry, military and medical.
With the help of computer software, laser presentation technology in performance has exploded in the last few years. Unlike the halogen, Xenon or LED lighting systems that have been used for a long time, the laser projection system provides more powerful visual and color effects. So this laser lamp is very popular in lively music festivals.
2. Laser lights and effects
Naturally the visual effect of laser lights for the festival is undeniable. However, for event photographers or stage photographers, these recordings can always be the last time their camera sensor works.
According to the ILDA (International Laser Display Association), the laser projection devices must meet IEC 60825 and ANSI Z136 standards with the maximum amount of light (MPE – Maximum Permissible Exposure). safety regulations for human eyes. In fact, only 8 cases of eye damage of 109,000,000 have been recorded in the past 30 years. However, there has not been any MPE indicator specifically for CMOS or CCD camera sensors.
Shape & quot; culprit & quot; Type IIIb for burning sensors
The nature of the laser is that the light source is parallel and has high energy, when it is received through the camera lens, it is further amplified. So as soon as it is captured into the camera sensor, the laser will overload and cause the pixels to be “burned”. resulting in dead spots on the sensor. With the most common types of laser beams currently present, these dead pixel regions often take the form of vertical or horizontal lines. And also due to light amplification through this lens, users of DSLR flip cameras and binoculars are recommended not to look through the viewfinder directly because they can cause eye damage. If you accidentally look directly at the laser source.
Image sensor with dead spots and laser color wrong
During laser show performances in the world and in Vietnam, attendees are often advised not to use video recording devices. For large overseas programs and video recording, producers often have to work with the previous lighting director to make their own areas that the laser does not project, for cameras and cameras. However, in the attendance area, there is no guarantee for your camera.