Understand 3D Films: Learn About the Principle of Polarization

[matonski]

Circular polarizers are a bit of a min-nomer.
They are really linearly polarized and then have a quarter wave plate to rotate the polarization.

You use circular polarizers because two different linear polarizations would have different effects on reflection from the screen or reflective objects in the shot.

A quarter wave plate turns the incoming circularly polarized light into linearly polarized light. Left-hand circular and right-hand circular will end up oriented 90 degrees from each other. Then you can selectively block one with a linear polarizer. Thus, the 3D glasses consist of a quarter wave plate followed by a linear polarizer.

The main reason for using circular polarization is so that each eye still gets the correct image even if you tilt your head.

 

[sophiecentaur]

Wouldn't those people have the same problem with their normal vision. When all is said and done the 3D technology is no different then how we see 3D all around us. We see two different images with different angles.

Yes, many people just don't have (or use) binocular vision. Giving them two stereo images won't portray a 3D effect. Stereo is not 3D - it's stereo.

But all of us get 3D information from other clues than binocular vision, like parallax when moving your viewpoint (moving the head) and contrast; distant objects are subject to scattering effects more than near objects (I think it was called 'perspective of light' by the old painters). Stereo only carries two images and it can be very striking at times but very much gives a feeling of 'layers', rather than natural 'depth'. You can see this effect even through large binoculars, which produce an exaggerated / artificial stereo effect due to the effective wider spacing of you eyes and the magnification of the image.

The stereo system cost is around twice that of a single image. Also, to get a 'good' pictorial effect for every scene in Stereo, you have to make significant compromises in the composition, depth of focus and layout - which actually restricts you quite severely at times.
Yes, it's a potentially very dramatic medium in certain appropriate circumstances but it certainly isn't what it's been cracked up to be. Big, sharp, bright pictures with good colourimetry are what is needed most of the time and, of course, Good Programme Material.

 

[Andy Resnick]

[...]colourimetry [...] Programme [...]

Ah... now I understand your 'plug-and-chug' comments. cheers!