Active 3D stereo originally was developed as a single workplace/station solution. The objective was to provide stereoscopic vision to a person looking at a computer screen.

The idea was to deliver the two different visuals for the two eyes by quickly alternating the pictures on the screen at a frequency of about 120 hertz. This means, that the picture for the left and right eye alternate 120 times per second. To prevent the “wrong eye” seeing the “wrong picture”, this technique leverages shutter glasses and an emitter for synchronization of the glasses and the screen of the computer.

Due to the high frequency users do not recognize that the pictures are actually flipping back and forth. The spectator sees two different pictures, one through each of her eyes – creating a stereoscopic effect.

In addition to those single workstation solutions we now have access to special projectors that work along the same principles, allowing a larger group of people to enjoy stereoscopic vision. However, it is important to note that people that suffer from medical conditions like epilepsy or seizure disorder must not be exposed to active 3D stereo visualizations. For those individuals, the high frequency of the visualization can trigger serious health issues.


Active 3D stereo has the following advantages

• Works with only 1 projector
  
• No loss of brightness due to polarization filters (as used in passive 3D stereo)
  
• Works even if spectators tilt their heads
  
• Works on white surfaces
  

Disadvantages of active 3D stereo

• Shutter glasses and projectors/screens are more expensive than with other techniques
  
• Can be stressful on the spectators eyes
  
• Not suited for (semi)public events as one can never exclude the presence of people with medical conditions that prevent the usage of active 3D