Re: image on screen from tv projector

Dear Tom,

A TV projection device works like a movie or slide projector. A projected image on a screen is called a "real image" (see bottom of picture)

Since the rays cross in the lens, the picture is "reversed". The original pattern behind the projection lens must be "wrong side up" if it is to appear correctly on the screen. The image which we see in a mirror is NOT projected. The image which we wee is called a virtual image because we think we see something straight ahead while in reality the rays bounce back on the mirror (see top of picture). The image is not "reversed", since in the mirror, we still see our head on top of our shoulders. A right-handed screw, however, looks lefthanded in a mirror. There is more food for thought than one might think at first glance.

Best regards
Werner Sieber