f/1.4

Back in the day, when I was a teenage member of Accrington Camera Club, it was all about landscapes and print quality and the zone system and everything being sharp and in focus and deep depth of field. Our hero was Ansel Adams, who founded the Group f/64.

But now it's all about having just one bit of the image in focus, it's about bokeh, it's about shallow depth of field. And if someone could manufacture a lens that was MINUS f/1.8 they'd probably make a killing.

I read somewhere recently that amateurs obsess about cameras, professionals obsess about lenses, but photographers obsess about light.