Ever wondered why people in the 1840-60's photos look so sour? Nobody ever smiled!
No, it was not because they were rigid and unfriendly! It took so much time to expose the picture that the subject could not blink, let alone smile, otherwise the photo would come out blurry! In early camera types exposure could take up to twenty minutes!
In fact the exposure of the very first photo taken lasted 8 hours! It was taken by Joseph Niepce and was called "view from the window," dated 1826.
The exposure time was so long that photographers used neck braces to clamp the subject's neck and head into place. Ouch!!