Ever wonder what makes for great photos?  Often, the general population will rely on the camera settings to do most of the work but to understand what these settings are will help you to take better photos.  I will cover Aperture, Shutter Speed and ISO.

Aperture

Aperture controls how much light enter the camera through the lens.
The more open your aperture, the shorter the depth of field.
The more closed your aperture, the greater the depth of field.
An f-stop such as f/4 will have a more open aperture and thus a very short depth of field.
An f-stop such as f/32 will have a more closed aperture and thus a longer depth of field.

Fiddler

"The Fiddler"

A large aperture (same as a small f-stop) created a very shallow depth of field. I wanted just the end of the fiddle in focus with the fiddler being recognizable but blurry. My intention was for the eye to focus on the curl.

Desert View "Desert View"

An f-stop of about f/22 keeps the foreground to the background in focus.

Shutter Speed

Shutter Speed controls how long the light entering the camera exposes the sensor.
The faster the shutter speed, the sharper the image. (as long as you are in focus)
Rule of Thumb: try not to hand hold anything less that 1/60 of a second.
Shooting at a slower shutter speed requires a tripod or a way to brace the camera. Even the strongest and steadiest of people can still cause camera shake when pressing the button.
If you have a tripod and a cable release, you can have as long of a shutter speed as you want.
If you want to stop the action, such as a dog running, choose a very fast shutter speed.
If you want to blur the action, such as with a waterfall, choose a very slow shutter speed.

Zion National Park  "The Narrows"

Long exposure led to a nice cotton candy effect to the water.

ISO

ISO numbers measure how sensitive the camera is to light.
Lower ISO #'s such as 100 and 200 mean the camera sensor is less sensitive to light
Higher ISO #'s  such as 800 and 1600 mean the camera sensor is more sensitive to light.
Lower ISO's mean you will have less grain or noise in your images
Higher ISO's mean you will get more grain or noise in your images.
I keep my ISO at 100 most of the time unless I am in a situation where it is too dark and I need to get a stop action photograph.