I'm a sucker for chronological photographs - like this series of photos Nicholas Nixon took of the Brown Sisters over a course of 25 years:
Begun in 1975, Nixon's annual group portraits of the artist's wife Bebe and her three sisters comprise his most well-known series. Collectively, they represent a distinct take on the tradition of portraiture for their rigorous simplicity in mode of conception and overall romantic beauty. Through this picture-history of the four Brown siblings, Nixon chronicles, almost methodically, slivers in time of the dramatic, ever-changing aging process by way of which familiarity and permanence may also be found.
For this ongoing series, the artist adheres to two unwavering constants. First, the sisters always pose in the same frontal sequence; Laurie, Heather, Bebe, and Mimi. Second, regardless of how many negatives exposed, only one is selected for printing from each individual year's batch.