So you've dug through your parents' basement, pulled out their vinyl album of Michael Jackson's Thriller and bought yourself an old record player. And for the last three weddings you've attended, you found the perfect outfit at that great vintage clothing shop downtown. Old is the new "new."
In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.