Nice shots Cindy. I had the "G1" version and have upgraded to the G2. However, I learned taking shots with either lens that I had to keep my shutter speed equal to my focal length. (Shutter speed = focal length X cropped sensor). If you are shooting at 600mm and your camera has a 1.5x cropped sensor, you should try to get your shutter speed above 1/900 sec. I shoot with the Canon 7D II, and I am always above 1/1000 and even as high as 1/1600 with birds stationary. This formula works well in bright sunshine. I had a chance to use a borrowed Canon 400mm f2.8 lens. I would rather use the Tamron 150-600 any day for capturing my ducks in flight.