What does "AR" stand for?
AR stands for Accessible Radiation. The laser class of the projector is specified according to the Accessible Radiation (AR). It is the maximum possible emission that may exit the laser aperture. Limit values are given in IEC 60825-1 „Safety of laser products, part 1".
The MPE in contrast to the AR references the laser emission in a public area - which is completely different!
Laser damaged camera sensor / video projector - was it dangerous for human eye as well?
If your camera sensor or video projector has been damaged by laser beams, the show was not necessarily dangerous for human eye:
Camera sensors and video projector LCDs are much more sensitive to light impact than the human eye.
If filmed from a distance, lasers normally don't harm camera sensors, but if you zoom into the beam, the optics act like a burning glass - and focus the already very sharp beams to the sensor (which in most cases is also no "real size" sensor, but a smaller one -> even more impact)
The human eye does not zoom, and the reception area is much larger compared to the actually projected image on the retina.
A safe laser show (class 3R in MPE area) does not harm human eyes but can damage your camera/photo sensor or video projector.
Do lasers damage video or photo cameras?
Yes, lasers can damage video cameras.
This is due to the very focused rays. A video camera has a very sensitive sensor to transform the immitting photons to electronic impulses. Laser beams have a very high energy density in the point where they hit the camera sensor. The distance to the laser is a crucial factor: The farther away from the laser source, the less dangerous is it to film the laser show.
Using an optical zoom (or other lenses) increases the danger of damaging the camera sensor, as it focusses the beams even more to the sensor.
In professional laser shows, the laser operator normally specifies certain safety zones in the software to have the laser blanked off at the camera positions.
Do not film laser shows from a very close distance!
Do not zoom into the laser beams!
Do I need special knowledge to operate a laser projector?
In general there is no deeper knowledge necessary to operate a laser projector in a physical sense. However, laser light may be quite dangerous if it is not properly used.
Due to the coherence of the laser light (same direction and wave characteristics of the light - different to normal light sources), the very sharp rays can be dangerous to human eye or immission sensors.
However, if you respect you local laser safety regulations, it is possible to make a safe laser show.
The regulation IEC 60825-1 is internationally valid and provides information about laser safety terms. Most countries refer to that regulation in context of laser safety.
However, some countries may have much more fear of the "laser mystery" and thus may have stricter regulations.
However, the responsibility for laser operation is with the actual operator. So being careful is most important.
Some things we recommend to respect:
- - never shoot single beams to the audience. You may shoot them above their heads (min height 3m) as strong as you like.
- - use a safety shut-off option (button etc.) to be able to switch of the system, e.g. if somebody tries to manipulate the lasers during operation or if somebody enters the laser safety area
- - keep people under age away from laser devices
- - familiarize yourself with laser safety prior to operation. Some countries (very few only) may need a Laser Safety Officer on site during operation
Laser projectors are not dangerous themselves - the danger always comes from improper operation.
What is the required minimum distance to a laser projector to do a safe laser show?
There is no general value available to determine the actual necessary distance. There are many factors relevant to the actual determination. Please see only a few:
Scan speed, point rate, scanned pattern, beam divergence, the output power of the laser projector, the beam diameter at the aperture, etc.
Internationally the IEC 60825-1 Laser Safety Regulation applies.
It defines the power of laser class2 in public area as safe for laser shows.
If people can walk underneath the mounted laser system, minimum mounting height is 3m. Please respect the actual emission in public area to not exceed laser class 3R.!