I can't recall where, but I thought I had read of an advantage that 1-series bodies had over other series when it comes to the speed of lens focusing. Meaning a Ring USM lens will focus faster (mechanically) on 1-series vs 5-series. Is this true, am I dreaming, I can't find any word/spec on this again and I'm wondering if I just misinterpreted something.
As you may have guessed, I'm considering purchasing a 1D4 to compliment my 5D2 to shoot sports.
Thanks in advance for the insights!