This second picture demonstrates some of the unique results that can come from a DSLR. At an aperture of f/1.8, there is only a small area that is in sharp focus. This is achieved through a very open aperture, meaning more light is let through the lens. As the f-stop gets smaller, the lens is more open and the depth of field decreases. To get an idea how the f-stop works, turn off all of the lights in a bathroom and then turn them on while watching the pupils of your eyes. When it is dark, your pupils get larger, allowing more light into your eye so you can see, similar to a camera lens. When it is lighter, the pupil gets smaller so a larger f-stop can be used on a camera to maximize depth of field.
I took this picture last fall on a walk looking at all of the trees in my neighborhood. There were some spectacular colors, however I thought this shot captured something not usually seen or seen and overlooked. I liked how the shallow depth of field focuses on the few leaves in the front. I converted it to black and white from the yellows because I felt it better represented what was to come with winter.