Watching 30fps stereo on a DLP projector running at 60hz is a pleasure. It's not so much the framerate as the fact that an LCD screen does not update the entire

Watching 30fps stereo on a DLP projector running at 60hz is a pleasure. It's not so much the framerate as the fact that an LCD screen does not update the entire image at once, but scans through it one line at a time. This way you don't have a single time point where the entire image is just left or just right. Updating the entire screen at once, at 120fps, is what 3d televisions (and DLP projectors) do, in addition to providing an external sync trigger signal for shutter glasses to latch onto. That is what makes a display device 3d compatible, not the frame rate in itself. That said, if you have a high enough framerate on an LCD you can simulate the global screen change effect by just showing each frame longer, for example running a 120hz screen at 30fps stereo (60 fps total), and showing each frame twice, giving the screen time to update.