I'm often asked why the subjects in "heirloom photos" aren't smiling. The answer is simple. Cameras in those days didn't have the capability to snap a quick shot--the shutters were all very slow. So, a photo session could take a long time. People had to sit very, very still for each photo as they waited for the shutter to close. When a subject would move (as with a fluctuating smile), the finished photo would be blurred because the camera would catch the slight movement. It is difficult to hold the same smile for 30 seconds or longer. Can you imagine asking a child to sit still, and smile for 30 seconds these days? The same was true then.