Selective Focus for Impact
600mm lens @ f 4
300mm lens @ f2.8
There are lots of ways to add impact to our images, but my personal favorite may well be the simplest. Shooting in Aperture Priority Mode is a great way to control backgrounds and force the viewers eye immediately to your primary subject. Opening your lens' aperture to its' widest setting will cause your photos background to go soft and concentrate the focus on the main subject of the image. For me, that generally means that my birds are going to be sharply focused, while my backgrounds are going to appear extremely soft. Nothing really earthshaking here, as portrait photographers have been using this technique since the beginning of time. While landscape shooters tend to want everything in the image in sharp focus, lots of wildlife photographers seek just the opposite.
Your lens are going to dictate just how well you can execute this technique. Better lens have wider aperture settings, and that translates to even softer backgrounds. There's a good reason we pay more for lens with openings of 1.4 to 2.8. They focus faster, and they simply give better results. However, experiment with whatever you have in your bag, and I think you'll be surprised with the results. Happy Shooting.