Assault on the senses...

[White-Light]

Chromadepth.

Thanks Karl.

[LaserCo]

Has anyone worked with dividing up the frames displayed on a projector, displaying the odd frames with a vertical polarization and the even frames in a horizontal polarization and viewed thru glasses with similar orientation of a polarizing film?

I had thought about this several months ago and am glad I seen this thread (While searching for Karl's "variance tips" thread) which reminded me about this.

Also, is there any software already setup for something like this?
Is it in the ILDA format?

I am guessing that this is not something that would require a certain DAC.

I see that there is mention of an IPAS routine for 3D Studio r4 but it is using ChromaDepth over here:
http://www.chromatek.com/Printer_Fri...th_primer.html
but yet this seems to be some proprietary format that is most likely claimed by the company.



BTW... Great thread!

[Jem]

Providing there were only single lasers for each colour in your projector*, you could just buy some halfwave plates and place them at the output of each laser, these could then be rotated to acheive any polarisation angle you desired. You could have each colour set to arbitary angles or set them all the same

* Would more than likely even work with knife edged multiple lasers provided no PBS was involved.

[planters]

3D images...neat.

Most of the diode based projectors already are using wave plates and PBS cubes to combine beams. Polarization control could be provided at the expense of 50% reduction of power output by alternately modulating each polarization.
Alternatively, two projectors each with a polarized output and no PBS or polarization beam combining could independently project two images overlapped to a single field. This would eliminate the need for tight timing coordination of alternating frames and just require reasonable co-alignment and similar magnification and rotation of the two images.

[Stoney3K]

3D images...neat.

Most of the diode based projectors already are using wave plates and PBS cubes to combine beams. Polarization control could be provided at the expense of 50% reduction of power output by alternately modulating each polarization.
Alternatively, two projectors each with a polarized output and no PBS or polarization beam combining could independently project two images overlapped to a single field. This would eliminate the need for tight timing coordination of alternating frames and just require reasonable co-alignment and similar magnification and rotation of the two images.

Even if the beams were combined with a PBS, if you used polarized glasses, the left eye would only be able to see the image from the horizontally polarized laser, and the right one would see the image for the vertically polarized one, even if they were being projected through a single galvo.

If you use a 1/4 wave plate and circular polarization, you'd be able to use those inexpensive RealD glasses.

The major issue is going to be how to get a galvo to scan fast enough to (seemingly) display two simultaneous images without significant flicker. I guess some clever optimization techniques taking advantage of the minor difference between the left and right eye could be a useful tool here.

Alternatively, two projectors each with a polarized output and no PBS or polarization beam combining could independently project two images overlapped to a single field. This would eliminate the need for tight timing coordination of alternating frames and just require reasonable co-alignment and similar magnification and rotation of the two images.

That's also the most effective way to project 3D video using two projectors, although it does require a silver screen, and the exact alignment of two projectors overlapping a single image is kind of challenging.

With the Casio projectors being so compact, I can see a project for an inexpensive, mobile 3D cinema projector in the works. Will definitely turn heads at LAN parties!

[planters]

I am agreeing with you that passing through the PBS will not present a problem. In fact,t it will be necessary if the two polarized input beams will have to be co-aligned in order to pass through the single scanner.

The advantages of the two projectors are significant. Rather than the two polarization fields having to share time on a single scanner ( the scanners are almost always a speed limitation) the two independent scanners may produce a final 3D image that has less flicker than a single conventional 2D image. This would be something like a temporal anti-aliasing.
Often in these beam combining processes the most difficult issue is magnification. As an example, imagine if the two projectors are spaced far apart and that they project on to a screen on opposite sides of the center line. The angle of incidence will cause the image to increase in magnification from right to left in one case and from left to right in the other case. The projectors should be as close together as is practical, oriented symmetrically to the screen and similar in design to simplify the set up.