Playing with the f-numbers (Av)

The aperture stop of a photographic lens can be adjusted to control the amount of light reaching the film or image sensor. In combination with variation of shutter speed, the aperture size will regulate the film's degree of exposure to light. - wikipedia.

In most canon DSLR, you can get the aperture priority by setting the dial to (Av). The smaller the number means the bigger the opening and allow more light to pass thru. In Av, the shutter speed will be shorter to compensate the big aperture opening.

Since I'm just using a kit lens, there is no way I can reduce the aperture below 3.5 and the f-number will become bigger when the lens is further zoom in. The effect I get when using a small f-numbers is the small depth-of-field and in other word is the object close-up will be in focus and the background become blur. This are some of the images I took today at Youth Park.

The setting are:
f = 4.5 - 5.0
ISO = 400
Mode = Av