Old photographs tend to have one thing in common, no matter the place or the subject: none of the people in the pictures could ever crack a smile.
Was it because they were all miserable, all the time?
A new video over at Vox has the answer:
The simplest explanation is exposure time - this is basically the amount of light a camera needs to record an image. The longer the shutter is open the longer the film is exposed to light.
Early cameras and film did take longer.
People couldn’t hold their smiles in place for that long. If they did, the photo would have almost certainly come out blurry.
And then they’d have to sit for it again.
As tradition had it, people were used to sitting in for painted portraits: these commissioned, unique paintings often took days, if not weeks of painstaking work.
As technology advanced, so too did perceptions of photography, giving way (eventually) to the smile.
And then the selfie was born, and humanity went backwards again.
If you want to learn the technicalities, you can watch the rest of the video, below: