[Nepeta]

Why are so many photos taken at night ???

Vampire blood ???

There are several things wrong here:

1-ordinary people taking photos of their kid with expensive color film and developing did not take pictures that were chancey--every shot had to count.
2-color film in the 1960s--I'll assume this is Kodacolor--was nowhere near as sensitive or "fast" as films that came along later. You shot in good sunlight, or you wasted a shot, or you shot indoors with a flash at a birthday party.
3-ordinary people did NOT use fill-in flash in twilight settings to get mood shots of their kids in the 1960s. You just won't see it.

[Tennessee Nana]

My father had a big Brownie

he took many photos of us kids

In 1961 he took photos during the day in bright sunlight