I've been trying some backyard bird photos at a feeder. I'm usually shooting from 30-35 feet away, from sunlight into slight shadow. I'm using a D50 with the kit lens (70-300mm 4.0) and used a Kenko 1.4 TC on this shot on a tripod. My problem is the softness of the subject. I can't seem to get a crisp shot. This was shot at f5.6 at 1/125, center metered, in Program mode. Any thoughts?