How Do 3D Movies Work? 

Source of pictures:pixabay.com

"Mackle,are you freethis weekend? Let's go to thecinema. Ijustheardofa new movie.Its3D effectis fantastic!" Itwasa message fromhisgood friendLinda.Helikes watchingmoviesvery muchformovies are always full of imaginationand alwaysbrought himnoveltyand happiness.He particularlyprefersblockbusters with3Deffects, so he acceptedthe invitationwithout hesitation.

At the weekend,MackleandLindawent toa movie theater and boughttickets forthe hottest 3D blockbuster of the winter.Mackleput on the 3D glassesprovided by the service personnel.Hesat down andwaitedfor the movie to start.

The moviewasextremelyamazing. When hewas going to the bathroomhalfway,he tookofftheglasses andwalkedout of theprojection hall.However,hewas unwillingto misseven one plot,so helookedat the screen before going out. "Oh, I cansee nothing,"Hesaidto himself, "I could justsee the image. Whycan't I see anything without 3D glasses now?"He wasthinking about this question on the way to the bathroom. Whycanhesee3Dmovieswith the help of 3D glasses? How is the 3D moviefilmed?

3D movies are notfilmed withcomplex methods.They come intoplay byapplying principlesof optics and how we look at things with our eyes. Due to the different positions of ourtwoeyes, the sights seen by left and right eye are actually not the same.Thesubtle difference of two sights enable people to perceivethe sense ofthree dimensions and distance. Wecan feelthe threedimensionsof objectswhendifferent imagesarerespectivelysentinto two eyesthrough a certain method.

Whaton earthisgoing on? In fact, the 3D movie is shot by two cameras at the same time, just like the two eyes of people.The pictures filmed by disparate camera havenuances.When the film is showed, two different videos arescreened by twoprojectors. Therefore, two images are simultaneously displayed on the screen. If you don't wear 3D glasses, you will see the overlappedpictures, whichare extremelyblurred.So howto show different pictures for two eyes respectively?

We need to puta polarizerin front of the two projector lenseswhen the film is screened. What is a polarizer?Thenatural light is made up of light raysfromall directions. The polarizeristhe lenscomposed of tiny gapswithonly one direction. When light rays pass through the polarizer,otherlight rays thatcomefromdifferent directions cannot pass.Onlythose light rays having the same direction as thegapcan pass through the polarizer.

Two projectors are installed withpolarizers with gaps ofdifferent directions. For example, if we put apolarizerwith gaps ofthe vertical direction in front of the first projector, only the vertical light can pass throughit.Weplacedanother one with gaps ofhorizontaldirectionin front of the second projector,andonly the horizontal lightcanpass through. In this way, images projected onto the screen are composed of two sets of light raysofdifferent directions.

The nextproblemcan be solvedby"3D glasses".Youmay have known thatthe 3D glassesarealso polarizers.Its two lenses are two polarizersofdifferent directions, corresponding to the direction of the light rays reflecting from the screen. Two sets of light rays in different directions will enter into your two eyesrespectively, instead ofintobotheyes simultaneously, and the brain willinformyou that these images are three-dimensional.

This iswhy you can seethe 3D movie.What do you think?Is it amazing?

Author: Ya Wen