Christmas, 1928, Elyria, Ohio.

Left to right: Bill, Marilyn and Stan. The explosions of light on the tree are from the bulbs, one right next to Dad's face. They look rather stunned, as if not quite believing their luck ("A train! A real train set! With a crossing gate and cars and everything."), or the notion of sitting and facing a camera is still too new.

Think about this: two of my younger children are about the same age as Bill and Stan. In their world, they not only know what a camera is for, but they know that they can look at the back of the box, press a button, and see themselves as they were a few moments before. Nothing unusual.