What optical knowledge does hand shadow, photography, projection and reflection correspond to?

Solution: A, hand shadow is shadow. When light travels along a straight line, it encounters an opaque object, and the dark area behind the object is called a shadow, so A is wrong;

B, photography is the use of convex lens to reverse image, restore, true, and the lens is the refraction principle of light, so B is wrong.

C, the projection is inverted, enlarged and true by the convex lens, so C is correct;

D. reflection is imaged by a flat mirror, and the calm water surface is equivalent to a flat mirror. The image formed by the plane mirror is symmetrical with the object about the water surface, so it is inverted. Its principle is the reflection of light, so d is wrong;

So choose C.

The formation of various shadows is related to the propagation of light. This topic should understand the principles of hand shadow, photography, projection and reflection and their optical principles. We should use the linear propagation of light, light reflection and light refraction to explain the reasons for the formation of these "shadows".