What if you could take the same picture 30 years later?
Porsz got a local newspaper to help; they'd run the original photographs with an appeal for information. And some of the subjects have come forward. The amazing thing is, these weren't posed photographs. Porsz didn't know any of his subjects; they were captured as he practiced his street photography.
"I love capturing spontaneous moments and taking pictures of people," he told the Mail Online. "If something caught my eye, I would snap it. But if I'd asked the subjects to pose, it would have ruined it."
Porsz is continuing his project and hopes to eventually produce a book.
More images and a story are over here.