Ever wonder why it's so difficult to focus fast lenses with a DSLR viewfinder?

primeshooter wrote:

I've been saying this alot lately to people who keep chiming in "oh just manual focus your 1.4 prime lens". Oh yeah? Unless you have a focus screen that shows f/1.4 you ain't gonna get any different resultant focus than the autofocus would give. (pulling focus manually to the rangefinder dots will give the same focus as AF).