I almost always shoot in aperture mode, as it allows me to control the depth of field or zone of focus. I use this technique to control what the viewer “sees” in my photograph or to call attention to a particular part of the image or to isolate the primary image from the foreground or background. Combing this technique with the image compression of a telephoto lens, one can really start to isolate the subject. In the image below, I used a wide open aperture on a 200-400mm zoom set at 310mm and focused just in front of of the cheetah. Focusing in front of the Cheetah allowed me to keep the first cat in crisp focus while allowing the second cat (only three feet behind the first one) to go past soft focus and begin the transition into the blurred background. The result is a tact sharp cat in the foreground with a pleasing out of focus background, yet showing enough detail in the second cat to maintain interest. Having shot with the 200-400 for a number of years, I am pretty good at guessing the hyperfocal distances (I’ll save that topic for another post) within my normal shooting ranges. Like most shots, when you take your time and make use of your knowledge, you will increase your chances of walking away with a solid image.
Cheers and happy photo’ ing.