Hi eml58, thank you for taking the time to reply...I really appreciate it. I went back and found your article, initial views of the 200-400mm. In that post, you stated that you need to add 2/3 stop exposure when using the 200-400 compared to the prime...are you still finding that? At a recent show, I tested the 200-400 vs the 300mm 2.8, and I also noticed that the pictures were slightly darker. I did read the explanation from privatebydesign, just wondered if it changes the way you set your exposure? I am pleased to hear, that the Focus Tracking is spot on!! I also shoot with a 1DX, what AF case number do you use most often?
BTW, your recent image...running Kudu very impressive...actually all your images are classic!! The big cats, are also on top of my list of favorite aimals...I hope someday I will have the opportunity to photograph these amazing animals.
Looking forward to seeing more of your images.
If your shooting in Manual, you need to compensate for the 1.4x Converter once you engage it, if your shooting Aperture or Shutter Priority, the Camera takes care of it, I tend to shoot Manual and compensate with ISO adjustments.
I shoot Case 2 mostly, Tracking Sensitivity set to -1 or -2 depending on the situation, Accel/Decel set on 1, AF Point switching set to 0. All of this I set up in "My Menu" so I can adjust on the Fly when necessary. I set C1 for Still/slow moving subjects (Aperture Priority), C2 for Fast Moving subjects (Shutter Priority) & C3 is set up for Landscape (Not used too much I'm afraid). I shoot almost exclusively in AI Servo, either Centre Spot Focus for slower standing Animals, and have the Depth of Field preview Button set to switch to Single Spot 61 Point Tracking for Fast Moving Subjects. That's about all my Brain can handle, I vary ISO a lot to get the Shutter Speeds I need, and although there's loads of Hype about the 1Dx ISO ability, and it is good compared to previous Bodies, I try not to get the ISO above 1250, I'll go to 1600 in a Pinch, and nearly always shoot 200/400 or 800 ISO for best results.
Attached Lion Cubs Playing with the Sun setting behind them.
1Dx 200-400f/4, Shot @ 406mm f/5.6 & 1/200th ISO800