16
Lenses / Re: 300 f/2.8L and 400 f/2.8 at f/2.8
« on: April 21, 2013, 09:34:40 PM »I'm not sure if the 400 focuses slow, but it definitely does "slower" vs. the 300. I'm serious, as I've noticed this even before you asked.
I think you're right, that the 300mm focuses faster than the 400mm. The 400mm is no dog, but I remember being surprised at how much quicker the AF of the 300mm felt, when I played with it some time ago.
I can't recall which body I used, but it could be on my old 50D (your 1Dx can drive the AF motor faster due to the higher battery voltage).
