Is this a thing?
When I watch 3D movies at a regular theater the main annoyance for me is the brightness of the display (IMAX / whatever doesn’t seem to make a difference).
I wondered if it is possible to buy glasses that could brighten the display a little – either by some kind of powered light amplification effect, an unpolarized lens that just collects light, or an active shutter that could work with a public cinema screen?
I am no expert on optics, I suspect the question might be dumb…
3D glasses, polarized or active lcd shutter work by blocking some of the light to each eye so by definition less light is reaching your retina. Unless they increase the brightness of the projected image, I don’t believe this is possible.
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What I mean is, some way of boosting the amount of light each eye gets such that even with each view being obscured 50% of the time, the overall effect is similar to the amount of light we get from just viewing the screen. e.g. instead of blocking the light completely what if the glasses were designed to just scatter it when they are out of phase?
I dunno, like I say, it might not make sense.
I won’t say there are no dumb questions, but they’re probably fewer in number than most people think.
Fins has it basically right – most 3D glasses work by selectively blocking from each eye portions of the light that’s projected on the screen, so that the right eye only sees what’s meant for the right and the left eye only sees what’s meant for the left. (Hence the 3D effect). This is true whether the glasses are anaglyphic (that red-and-green or red-and-blue lens thing), linearly polarized, or “Real 3D” (which uses a combination of linear and circular polarization)
There ARE 3D systems which don’t rely on separating the right-eye and left-eye portions, and which therefore don’t reduce the intensity, although they still require special glasses. 3D relying on the Pulfrich effect only needs a filter for slight phase-shifting over one eye, and doesn’t eliminate most of the intensity. They used this for the halftime show at the 1989 Super Bowl XXIII, using glasses distributed through convenience stores and the like. Pulfrich effect is kinda iffy – it doesn’t work well for me.
Another 3D system that won’t reduce brightness is the p[atented sydtem called Chromadepth, which uses whatr is basically controlled chromatic aberration to separate images sent to each eye, keyed by color. Basically, red images appear closer than most, and blue images appear further away. The glasses used are basically Fresnel direct-vision prisms. AFAIK, the only supplier is American Paper Products. I’ve been playing around with these for the past several months, and it’s pretty nifty. The images don’t look weird if viewed without glasses, like most 3D images, yet they are strikingly 3D when viewed with the glasses on. Therte are lots of sites with Chromadepth images. (I first encountered it at a :“Haunted House” several Halloweens ago). You can buy the glasses online at several sites, notably Amazon.
https://en.wikipedia.org/wiki/ChromaDepth
The drawbacks are that the 3D isn’t quite as “deep” as with other systems. And you can’t simply shoot a scene and expect it to be faithfully rendered in 3D. A colored scene chosen at random will look like a mess through the Chromadepth glasses unless you’ve arranged things so that the scene adheres to the red-for-near. blue-for-far formula.
As far as taking the scene from pair of “standard” 3D glasses, you seem to be asking if you can put the image from each eye into a magic black box and have it come out brighter. That’s what Image Intensifiers do. Those infrared Night Vision goggles basically do the same thing, using a microchannel plate to intensify and convert to visible the infrared light coming to your eye. Those IR goggles work with visible lighjt, too, but the scene is rendered in green monochrome. You could do it with an anaglyphic 3D movie, with the separate green (or blue) and red images. You’d have the advantage of having it all appear in the same green, so you wouldn’t have that weird green in one eye red in the other to kinda make brown vision (that makesx things look really weird after you take the glasses off). But don’t expect the theater to provide these. Anaglyphic glasses are dirt cheap, at several for a penny in bulk. Night vision glasses cost several hundred dollars each.
And it won’t work for color movies,unless you don’t everything looking green (It’s not easy being green).
Another 3D system is to use an electro-optic set of glasses that switch each eye “on” alternately at a fast rate, so that each eye gets a right-eye or left-eye view of a fully illuminated screen. Such systems are called “active shutter 3D”. They have been used for computer monitors and home viewing, but only at a limited rate in movies. The reason is that the glasses, using liquid crystals or similar technology, are a LOT more expensive than the pretty inexpensive anaglyphic or polarized 3D, where the theater can basically afford to throw away glasses after each feature (I have no idea what proportion gets recycled).
Lastly, you can provide every audience member with individual monitors for each eye, or let then use their cell phone screens in a box viewer. But in that case, what do you need a theater for anymore?
Which, I think, all boils down to the fact that, for a good experience, 3D movies should really only be shown on projectors with substantially brighter output than theaters use for conventional movies. But those cost money.