The current Black and White challenge is dedicated to the Group F/64.
From Wikipedia:
Group f/64 or f.64 was a group founded by seven 20th-century San Francisco Bay Area photographers who shared a common photographic style characterized by sharply focused and carefully framed images seen through a particularly Western (U.S.) viewpoint.
Imogen Cunningham was the only woman in the original seven. She was fascinated by botany and it was one of her major subjects. The Hydrangea was one of her more famous shots.
Here is a link to her shot that I tried to replicate. I hope it works. https://www.pinterest.ca/pin/226868899949462770/
For your challenge - how about capturing opposites? For example up/down, left/right etc