Digital audio, video, imaging guide

As like other settings in digital cameras, most of the people always put aperture settings in Auto mode. Like other settings, with some experiments, you will be able to adjust aperture according to the conditions and what type of shots that you want to take. Unlike white balance and shutter speed, aperture make a lot of difference in images.

Aperture - definition
The diaphragm on the lens is the mechanism which enables the hole through which the light passes to change size. The hole is called the aperture. When the diaphragm is completely opened, the aperture is large, and it lets a huge amount of light thorough. When the diaphragm is closed to the size of a pinhole, the aperture is tiny, and it lets only a little bit of light through. With this in mind, you want to close the aperture on a bright and sunny day so as to not let too much light come through to the film or photo sensor. On a dark or dreary day you want to open the aperture so as to let as much light through as possible in order to get a good photograph.
Aperture settings, called f-stops, are determined by the manufacturer according to the focal length of the lens.

While the shutter speed controls the speed at which light is admitted, the aperture controls the amount of light that will reach the CCD. This can be imagined as black window that opens and closes continuously very fast (shutter) and a curtain (aperture) behind the window that controls the strength of the sunlight entering the room (CCD). The wider the aperture, the more amount of light that reaches the CCD.

If you are taking close-up then you should try increasing aperture as it will increase the Depth of field. Depth of field is the portion of image that is in focus. If aperture is large then, your subject will be in focus with background little blurred (because it is out of focus) which is very good for taking portraits or close-up shots which concentrates only on a single subject and not on the background.

In the above image, the spider is only in focus and not the background. The depth of field is high in this image that means aperture is very large.
If you increase aperture, depth of field will increase and if you decreases aperture, depth of field will decrease.
Taking the shots by increasing the aperture can also be helpful in low light conditions.