|What is the significance of polarizer transmission?|
|Polarizer transmission lets you estimate what will be the lumen loss due to the polarizer. For example, mounting a polarizer with 40% transmission on a 5,000 lumen projector will give output of 2,000 lumen.|
|What is the significance of polarizer extinction?|
|Polarizer extinction is a quantitative measure of its blocking power for the cross (orthogonal) polarization state. Higher extinction means better blocking.|
|Why high extinction is important?|
|The fact that polarizers have finite extinction contributes to an image artifact called "ghosting". Ghosting is manifestation of light leakage from a given eye image to the other eye.|
Ghosting is a prime quality degradation factor in 3D passive projection displays. It impairs significantly the 3D sensation, and can even ruin it completely in extreme cases. Therefore ghosting reduction is a major design goal in 3D displays.
|What extinction is more important: that of the projector polarizer or that of the eyewear polarizer?|
|Both are equally important. The overall system performance is determined by the worst polarizer between the two.|
|Can I eliminate ghosting by using very high extinction polarizers in both projector and eyewear?|
|No. There is another contribution to ghosting: screen depolarization. In fact, in typical situations this contribution is dominant. Due to this phenomenon, any increase in polarizer extinction beyond 1000:1 has little effect on the ghosting level.||What can I do to reduce ghosting?
|1. Choose a screen with best extinction|
2. Avoid content with high contrast gradients (black patch adjacent to white).
|What is better: circular or linear polarization?|
|The only advantage of circular polarization is its lack of sensitivity to observerís head orientation. However, compared to linear polarization it has the following disadvantages:
1. Lower extinction
2. Higher price
3. Color distortions may be noticeable in some cases.|
Circular polarization should be considered only in cases where the viewer is moving (like moving chair cinema).