Anaglyph (red-blue 3D glasses)
Touch of history - Anaglyph (red-blue glasses)
Anaglyph is one of the oldest 3D visualization technologies. It is bases on the well known red-blue or red-green glasses. It had played an important rule in the past, but it should be considered as obsolete nowadays. The anaglyph still has some advantages (simple glasses, works with standard printing techniques and visualization devices).
The principle of anaglyph work
We need again to solve the same problem – separate left and right image. Fo anaglyph both images are overlapped and each one is printed in different color. The glasses contain color filter passing through only the proper image color. Scientifically – the anaglyph is base don separating light of different wavelength.
Disadvantages of anaglyph
The anaglyph use color for separation – so the original colors of the image are totally corrupted. During the anaglyph visualization the human brains is strongly over-burned by the color reconstruction effort. For most of people this is a great discomfort. Different modification of anaglyph based on cyan or yellow filters are not able to solve this problem. A partial solution is a black and white only anaglyph using colors only for the eye separation.
Overview of 3D stereoscopic technologies:
| technology | color informations | rozlišení obrazu | projection | monitors / tv | num. of viewers | 3D cinema expenses [price / operating costs] |
| Active 3D | full | high | yes (2) | yes (3) | limited (4) | high / high |
| Passive 3D | full | high | yes | yes | high | high / low (5) |
| 3D Polarization Modulator | full | high | yes | no | high | middle / low |
| 3D Auto-Stereoscopic Monitors | full (1) | low | no | yes | low | - |
| 3D Anaglyph | very bad | middle | yes | yes | high | low / low |
(2) - active 3D is not suitable for large 3D cinemas. Active 3D glasses are expensive and servising is also hard job (repairing, replacing / recharging bateries, etc.).
(3) - active 3D displays (3D TV, computer 3D flat panels) provide the highest 3D quality from all 3D screens.
(4) - number of viewers is limited by expensive 3D glasses and the wireless signal range.
(5) - 3D Modulator is currently the best 3D technology for all modern 3D digital cinemas.