You can shoot all day long in your preset modes, but you will never be able to take full advantage of your cameras abilities until you begin shooting in your manual settings. But before you can do that you have to understand what each means.
Aperture: (AV = Aperture Value) Aperture is the hole that light has to pass through. You change your aperture to allow more, or less light through the lens. (a large aperture letting in more light, and small letting in less) On your camera the aperture will be shown as f/number. The smaller the number, the larger the opening. (i know that might be a little confusing, usually bigger number would mean bigger hole, but not in this case) The f/number is a ratio of focal length to aperture diameter (the size of the hole that is letting light through)
Now lets get to what this all means in your photograph. Basically, a small aperture (higher f/number) means your subject, as well as anything in front and behind will be in focus; and a large aperture (lower f/number) means your subject will be in focus, while your foreground and background will be out of focus, or blurred.
Here's an example:
In this image I used a large aperture. You can see the background is blurred.
In this image I used a small aperture. You can see the background is more in focus.
Shutter Speed: (TV = Time Value) Shutter speed is pretty self explanatory, it is the speed that the shutter opens and closes, allowing light to pass through the lens. A slow shutter speed will be open longer, allowing more light to pass through; while a fast shutter speed will open faster, allowing less light to pass through. The shutter speed is shown as a number such as 8000. What that actually means is 1/8000th of a second. That is a very fast shutter speed. (8 would be 1/8th of a second) If the number is shown as x", the shutter will stay open for x amount of seconds (8" would be 8 seconds)
Here's a few more examples:
1000 = 1/1000th of a second
250 = 1/250th of a second
4 = 1/4 of a second
2 = 1/2 of a second
1" = 1 second
2" = 2 seconds
30" = 30 seconds
With fast shutter speeds, movement will become frozen in your image, while a slow shutter speed will blur movement.
Here's an example:
In this image I used a fast shutter speed. The movement of the ball falling is frozen.
In this image I used a slow shutter speed. The movement of the ball falling is blurred.
How the two effect each other: With a fast shutter speed, you let in less light, so your aperture should be adjusted to allow more light to pass through, so your image wont be too dark. With a slow shutter speed, you let in more light, so you must adjust your aperture to let in less, or your image will be too light. Aperture and shutter speed are both measured in stops, so when you adjust one stop, you must adjust the other the same amount of stops to compensate for the adjustment. (this is called equivalent exposures)
Some other uses for slow slow shutter speed are: (I'll go more into detail on these later)
Night shots (or low light shots)
Light art (moving a small light source in a dark environment to create a stream of light)
To create blurred movement such as flowing water
Once you understand aperture and shutter speed, you won't believe how much your photographs will improve.
Remember: Don't be afraid to play with your settings, sometimes just reading about it isn't enough. Get hands on..practice different set ups until you figure it out. This can be a very confusing topic that can take some time to understand. Don't let the technical words scare you away, once you get the hang of it you'll completely impress yourself.
Keep on shooting. :)
Disclaimer: All photos are mine, unless otherwise stated. All opinions are my own. No monetary exchange occurred in exchange for this post.
