Sep 3, 2011

Aperture + Depth of Field

Scary word there. I had no idea what it meant up until a month ago. 
In short, your camera lens is like an eye. Excuse me, the PUPIL of your eye. It can open and close to let more or less light in. Same with a camera... the lens can open wider to let more light in, or close to shut out more light. Basically, aperture means opening: how far your lens is open. Okay, so you know that much. But you can't completely understand aperture until you know a little about:

Depth of Field
Some of you might know what that is. (Some of you might even know what aperture is.) In this case depth of field pretty much refers to the blur in the background of the photo. With a very small depth of field, you can't see very far, so the background gets blurry.  With a large depth of field, more is in focus. 

Now that you know that much, we shall combine the two words.

The SMALLER the aperture number, the greater the depth of field.
The LARGER the aperture number, the less depth of field there is.

The smaller the aperture number, the farther the lens is open.
The larger the aperture number, the further the lens is shut.

Let me explain the numbers.
Aperture on your camera is measured in f-stops. (fancy name, hm?)
On my camera, the f-stops go from 2.8 to 8.0.
Some cameras can go from 0.7 to 32. *jaw drop*

And I love how this blogger/photographer teaches about aperture:

    Things to Know About Aperture
    Small number = Big Opening = Allows in more light = Less time required for correct exposure = shallow depth of field.
    Big number = Small Opening = Reduces amount of light in = More time required for the same exposure = wider depth of field.

If you have your aperture set on, say, 3.2, and you shoot a photo, the background of your subject will be kinda blurry. (see below)

But, if you decide to shoot a photo on f-stop 8.0, your background will be much more in focus, as in the next photo.

Side by side they look like this:
f-stop 3.6                                                                    f-stop 8.0                                

See the difference? I really like playing with aperture. If you want a nice photo of a subject, but the background isn't ideal, or even if you just want the focus on the subject, use a small f-stop number :)

Or if your background is beautiful, and you want to get the full loveliness
of it, use a higher number. 

The bad news: if you are using a point and shoot, most likely you can't change the f-stops by yourself. The camera will do it for you. And sometimes the camera doesn't want what you want. My advice is to shoot on macro mode if you can. Play around, read your camera manual, and you will probably be able to find the macro mode. You will have to get in pretty close to your subject, usually you take photos of flowers or small objects on macro mode. You can get better depth of field shooting in macro.

For people with fancy cameras: Shoot on aperture priority for the most part, when you are playing with aperture. The camera will manually set shutter speed to match the aperture you set. You could also shoot on a completely manual mode if you are feeling adventurous. :D 

I'm seriously no good at writing tutorials, but hopefully you got something out of it.
If nothing else, you get some very distorted photos of my dear brother who held still for 10 seconds...just long enough for me to take a few photos to demonstrate this tutorial. He was nice about it.



  1. thanks for the tutorial! i wonder if my point-n-shoot has a macro feature? guess i'd better go find that manual... ;)

  2. Yep, it probably does have macro! :)