the effect in which one image transforms into another is known as
Morphing Morphing is a special effect in motion pictures and animations that changes (or morphs) one image or shape into another through a seamless transition. Most often it is used to depict one person turning into another through technological means or as part of a fantasy or surreal sequence. Traditionally such a depiction would be achieved through cross-fading techniques on film. Since the early 1990s, this has been replaced by computer software to create more realistic transitions.
Pinhole camera A pinhole camera effect can sometimes occur naturally. Small "pinholes" formed by tree leaves will create replica images of the sun on flat surfaces. During an eclipse, this produces small crescents in the case of a partial eclipse, or hollow rings in the case of an annular eclipse.