I took these sunset photos at Nosehill park which is in the deep NW part of Calgary. As the landscape darkened I knew the sun would stand out amongst the dark. Shooting at f/16 helped me get the round form of the sun as it dropped lower on the horizon, the fading light helping to define the round shape of the sun.
Nikon D90 1/400 sec. f/16 ISO-100 at 300mm
Nikon D90 1/400 sec. f/16 ISO-100 at 300mm