Here are some more examples:
In the first photo you can see that it is a very wide open aperture at f-1.2 and the depth of field is very shallow. Only one bottle is in focus and the ones directly in front of it and behind it are already starting to blur a little. And the farther in front or in back you get, the blurrier things become.
In the next photo, the aperture is a little more closed up at f-4.0 and more of the bottles are in focus. But the bottles at the ends are still blurry.
In the last photo, the aperture is even smaller at f-9.0 and all the bottles are clear and sharp. The depth of field is even getting great enough that you can start to see the wall in the background coming into focus a bit, which in the other two photos was so blurred that you couldn't tell what it was.
On an SLR camera you can choose your own aperture for your photos, but keep in mind that certain lenses can only open so wide. Some have only a maximum aperture opening of f-2.8 or even f-4.0, so those lenses wouldn't be able to open as wide as others that can go all the way to f-1.2 (like my favorite lens)! So if you like the look of a shallow depth-of-field, you'll want to look for a lens that has a very low aperture number.
Although I prefer shooting completely in manual mode, an easier way to begin experimenting with your aperture setting is to use theAV mode (aperture priority mode) on your SLR camera dial. In AV mode you can determine your own aperture, and the camera will automatically determine your shutter speed and ISO for you!
So... what if you have a point and shoot camera but you still want to get some background blur in your pictures? The good news is that you can, at least to a certain extent. Just set your dial to "portrait" mode, which has an icon that looks like a person's head. This setting will tell your camera to open its aperture as wide as it is able to. Awesome!
Next, I'll be teaching you all about shutter speed and ISO! In the meantime, I'd absolutely love to see your photos experimenting with your new knowledge of aperture! Feel free to participate in Shabby Blogs' first ever link party so we can see what you've posted on your blogs using your rock star aperture skills! How exciting!
