A question to those using the infamous 85 1.8... do you shoot wide open or stop down a bit for better DOF and/or AF accuracy? I used an 85 1.8 the other weekend for some gymnastics shots and found proper focus on my target areas to be a bit tricky with it wide open.
Usually I shoot the 85 f/1.8 at f/2, as well as the 100 f/2 and the 135 f/2. If the light is really bad, I will go ahead and open it up the extra 1/3 stop. Haven't noticed any difference in AF speed or accuracy. Occasionally I have stopped them down to f/2.5 in the rare, well-lit cave.
Proper focus is almost always tricky in gymnastics with the interfering backgrounds with lots of nice, contrasty patterns.