by peterr » Sun Apr 19, 2020 3:31 pm
Well with a small bird like this you are actually on a bit of a hiding to nothing. I have tried Malcolm's technique with small birds in flight, but with virtually zero success. Going through the maths, I think I can see why. Assuming that you are 4m away from the tree and shooting at F8 at 350mm focal length on FF, then you will have a depth of field of approximately 60mm. Assume that the bird is moving towards you at about 5mph (probably a low estimate) then this is more than 2m/s. Assume you prefocus just in front of the tree on the path the bird will fly and your camera has a max burst rate of 8fps, then you will get one frame every 0.125s. In the time between frames the bird will therefore move 250mm, which is more than four times more than your depth of field, so it will be through luck more than anything else to get it all in focus. Of course if you have a camera with a much higher burst rate, then your chances will be improved, but going to F11 will only give you about 85mm DoF, so you are still going to struggle.