Ask the editor is the spot where we try to answer readers’ questions.
Q: Why don’t all active 3D glasses work with any 3D TV?
Robert Elmes
Active shutter 3D glasses Active shutter lenses flicker between transparent and opaque 120 times a second
A: Inviting your friends round for the big game or even movie in 3D is not yet quite as straightforward as it should be. If your mate brings along his Sony 3D glasses they won’t be any use for watching your Samsung 3D telly.
This is because even though the active shutter 3D technology used by different manufacturers for their home-based 3D TVs and glasses is essentially the same (though different from the passive glasses variety used in cinemas), it’s implemented in slightly different ways.
Each manufacturer has developed its own system which links a sensor in the active shutter glasses with a sensor in the TV so that the images are synced with the alternating lenses (they flicker between transparent and opaque at about 120 times a second).
There are however some companies which are making the effort to produce ‘universal’ glasses which will work with any active shutter technology 3D TVs – which has to be a good idea with new glasses potentially costing over £100 a pair. Companies such as the East European brand XpanD have announced plans to bring such glasses to the market soon. Even with these, an additional syncing device may be required in some cases.
With passive lenses it’s not quite so simple either. They use polarising filters which sift out the light from the screen slightly differently for each to help construct a 3D image in the brain. But with some glasses the filters are aligned vertically, and with others, horizontally, so while some different brands may work with each other, not all will – the only way to be sure is to try them out.