The closer the aperture shape is to becoming a perfect circle, the more beautiful your defocused effect will be. That's why Minolta's specially-designed aperture blades produce a circular opening from their widest setting down 1.5 steps to help smooth a scene's out-of-focus areas. When you take a picture with sunlight shining through foliage, a picture at sunset or a picture of neon lights, the source of the light can be defocused beautifully. The number of aperture blades must be maximized to make the aperture as perfectly circular as possible. Conversely, each blade can be curved to produce a circular aperture, and thus a desired blurring effect.