I live in Florida and shoot mostly wildlife including the region's many wading birds and others. I recently acquired a D7100 and I am curious as to what settings others use for bird photos, including BIFs. Rather than static shots, I try to get shots of the usually slow moving wading birds just as they dart for a fish or make some other quick movement such as taking off. This usually requires a fast shutter speed to freeze motion, no less than 1000th. For birding I use a Sigma 150-500 usually mounted on a Manfrotto Carbon Fiber Pro 3 with a Jobu Jr 3 gimbal head and a Nikkor 70-300 VR (for handheld and BIFs). I shoot AF-C, Back button AF, Matrix metering.
1. What number of focus points are used? With the D7100 in crop mode, I can virtually fill the image area with 51 focus points. Nikon seems to tout this fact as a great asset to birders...true? Or, are fewer focus points somehow better? Is the trade-off that I am slowing the frame rate (I shoot in Continuous High) perhaps too much? At 51 focus points am I requiring that the camera do too much processing as a fast moving object moves within the frame such that I am actually missing focus?
2. Focus tracking lock-on (CS a3). Is this best set to off to capture rapid, unanticipated movement, or should it be set to one of the two shorter durations?
3. Finally, how do others set their ISO sensitivity? I have set U1 (aperture priority) to Minimum ISO of 100, Max ISO 4000, and Min SS at 1000th. I have set it this way to try to maximize the probability of a descent capture of a bird in motion even in low light.
Thanks in advance for your thoughts on these questions.