Our new 600 mm telephoto lens has been fun to experiment with. Large telephoto lenses have a very shallow depth of focus and only show a narrow degree of the horizon. This allows the photographer to isolate specific parts of a scene. In this photo, the big lens allowed me to capture the seagull as it flew over the prettiest section of the light show. F5.6 at 1/1250, ISO 500, 600 mm lens with 1.4 extender at 850 mm