If you find yourself squinting at the theater, it might not be because of the standard plot holes and hacky exposition. It could be the lens of the projector. The Boston Globe reports on an unfortunate trend in some big movie chains where rather than swap out the 3-D lens when showing a 2-D moving, they leave it in place. The result can be an almost 85% darker projection, and should have audiences throwing popcorn at the screen. So how do you detect if they’re showing the movie improperly, while still charging you full ticket price?

Well the first big clue is if the movie is really really dark. Then, in theaters where they use the Sony 3-D projectors, if you’re watching a 2-D movie and they haven’t changed the lens, you can look back to the booth. If you see two beams of light coming out, one on top of the other, that’s a Sony with the 3-D lens.

To save time and money, some projectionists simply aren’t swapping out the lenses. It requires entering extra passwords to open the projector and some theaters, in the rush to turn over as many theaters as quickly as possible, simply leave the 3-D lens in place.

So if you see that you’re getting “shafted,” complain to the manager and ask for it to be fixed or your money back. Or patronize a smaller movie house instead of the multiplex, where there’s less of a cattle call mentality towards the patrons.

A movie lover’s plea: Let there be light [The Boston Globe] (Thanks to RandomHookup!)

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.