3D image tracking - the size of the bird in your viewfinder matters
Black Tern, Red Deer, Alberta - the difference is how far the subject was away from the camera 3D image tracking is very handy when trying to photograph flying birds, although there are a lot of issues with it working well all the time. Some of them I have already discussed in a previous blog . While tracking black terns in Red Deer, I noticed a relationship between proximity to the camera, ability to get a focus lock, and the usability of any resulting image. The further away your subject is, the easier it is to lock focus and track it. The exception is when there is a lot of background clutter. The greater distance makes the bird appear to travel slower, the same way that a plane can travel at 400 km/hr but seem to only crawl across the sky. As the bird gets closer, it can dart across the field of view in no time at all. Your motion of following the subject has to be that much faster so as to keep the subject somewhat centered. So,...