Digital Photography 101: Aperture or F-Stop
Aperture is the hole which through light passes into the camera. Changing the size of this hole is what changes the amount of light that’s let into the camera. Like ISO and shutter speed, aperture plays a part in controling the exposure of an image, but it also has the ability to change another major aspect of your image — depth of field. What’s that?
Depth of field refers to how much of your image is in focus. A shallow depth of field (smaller f-stop) would focus only on the objects in the foreground, leaving the background blurry, while a wider depth of field (larger f-stop) will produce an image that has more of the background in focus.
f/1.8, 1/400, ISO 320
f/5, 1/125, ISO 640
Check out the example above. The first image has a shallow depth of field while the next one has a wider depth of field. Can you see the difference? On the first one you’ll notice that the foreground is crisp, but the background is blurred, drawing attention towards the flowers. In the second image, you can see far more detail in the stuff around the flowers.
This part of aperture gets a little confusing, because it seems backwards. If you can remember that, then you’ll be set. A larger aperture (bigger hole) has a smaller f-stop number and a smaller aperture (smaller hole) has a larger f-stop number. Confused yet? So was I. Here’s a visual.
This is my favorite pillar of photography because it allows me to change the depth of field and thus change the feeling within an image depending on what I need for a particular shot. For the most part, I shoot in the f/1.8-3.2 range for all of my photos because I love the blurred background. A great use for a wide aperture is landscape photography where you want to capture the whole scene and have it look crisp.
f/1.6, 1/200, ISO 160
f/5, 1/80, ISO 640
So, now you’re equipped with the basics of the three pillars of photography, all that’s left is practice! Feel free to leave questions below and we’ll do our best to answer!
*FYI: Some lenses don’t have apertures as small as what I’ve shown here, but if you’re wanting a good basic lens to practice on, the 50mm f/1.8 lens is affordable and does a really great job.