Digital cameras are having a comeback and you should join in on the fun.

Ivette Spradlin’s Instagram page is filled to the brim with images of people in masks posed in front of colorful and creative-looking homes, their gaze fixed on the photographer who takes their picture from at least 6 feet away.

Elliott Erwitt left his rented room at the downtown Pittsburgh YMCA in the fall of 1950, cameras in hand. The 22-year-old photographer walked up either Forbes or Fifth Avenue, documenting the people and...