When you consider razor sharp depth of field or crazy blurred background, you might think of the super fast lenses for 35mm cameras - the f1.8 lenses, the f1.4, and even the occasional f.95 lens. They will definitely deliver shallow depth of field. But when you step up to medium format (not to mention large format where f5.6 is speedy!) an f2.8 lens feels super fast. The f2.8 Zeiss Planar lens on my Hasselblad spends most of its time between f5.6 and f16. The subjects that I tend to shoot with this camera don't really need exaggerated depth of field and f5.6 gives me a nice pleasing background if I want to isolate something that's a normal distance from my lens. The other day at the park I set the lens to f2.8 just to play around. This is pretty shallow, really just an inch of two of grass is in focus. The lens was set at the closest focusing distance.
This one was also at f2.8, but I wanted to get a pleasing, useable photograph, not a freakshow. I selected the leaves closest to me, knowing that the sun streaming through the leaves behind them would create a nice blurred background.
And just for fun, I focused on a few strands of Kate's hair that I could see in the evening sunlight. Those few strands are crisp and clear, while everything else is soft and a little dreamy.
There's no point to this exercise besides just playing around. I do think shallow depth of field has its uses, but I avoid using much of it in medium format film. The margin for error is so steep and you only have 12 shots on a roll. Still, it's kind of cool to play with.
On a side note, I'm *really* starting to like Fuji Reala in 120 format. I've heard that Fuji may be phasing it out, so I might need to grab a stash for the fridge!