Barefoot Blue Jean Life: Aperture Basic Training

12 Weeks to Better Photos
by Joanna Bolick (Two Peas in a Bucket)

Week #1: Aperture basic training

One of the most necessary but oftentimes least understood parts of photography is Aperture. The size of the aperture, or f/stop, of a lens determines how much of your photograph is in focus. Generally, when you hear someone talk about f/stop, they are referring to aperture -- the terms are often used interchangeably. The f/stop on a lens can go from 1.2 to 22 or sometimes higher. (It’s not really important to this class for you to understand the mathematical basis for these numbers, but instead to understand what they mean to your photography.)

F/stops can be confusing at first. The f/stop numbers refer to how open or closed the aperture on the lens is. The wider the opening of the lens, the greater the amount of light that enters your camera at one time – which means that when your aperture is wide open your focus will be shallower and fewer things in your photo will be in focus.

The WIDER the aperture, the more light that comes through the camera -- because a lot of light is flowing through the aperture opening LESS of your photo will be in focus. A low f/stop, such as f/1.4 or f/2.8, is considered a wide-open aperture.

The SMALLER the aperture, the less light allowed -- because there is very little light flowing through the aperture MORE of your photo will be in focus.

The smaller the opening on the lens, the smaller the amount of light that is allowed to enter your camera at one time – which means your focus is deeper and more of your photo will be in focus.

The confusion for most people arrives when you try and put the f/stop number with these scenarios. In terms of aperture openings, f/1.4 would be a wide-open aperture on most high-end lenses, whereas f/22 would be a virtually closed aperture.

Basically, when you use a low f/stop, less of your photo will be in focus. When you use a higher f/stop, MORE of your photo will be in focus.

WEEKLY CHALLENGE: Exploring Aperture

First of all, we want you to operate your camera in Aperture Priority mode (often
indicated with an “A” or an “Av” on your camera dial. (Don’t worry about shutter speed as the camera will take care of that for you.) The goal of this challenge is to discover what different f/stop settings on your camera will produce for you and to become more
comfortable with selecting these settings to fit your subject.

The easiest way to do this is to find a fixed subject such as a flower, a tree limb, or in our case, a birdbath. (If you are outside in daylight, set your ISO to around 400. We highly recommend you try this first challenge outdoors, if it’s not too cold for you! If you are inside, you may have to set the ISO on your camera much higher like 1250 or even 1600. Your photos will be grainy, but you should still be able to tell what your aperture setting is doing to your photos.)

1. Set your f/stop (often accomplished by turning a dial, but check your manual if
you’re not sure) to the lowest setting it will go. Compose your image and use
either the manual focus or autofocus to focus on one particular spot of your
subject (the subject of our photos was the frontmost rim of the birdbath, and
we made sure to focus on this for all 3 photos). Take your picture.

2. Move your aperture setting to something around f/8. Compose and
refocus on the same element again. Take your picture.

3. Move your aperture setting to the highest setting it will go to (most likely
f/22). Compose and focus on the same element again. Take your picture.

Now bring these pictures into your image editing program and look at the differences in the composition.

1. On the first image, you will have very little outside the initial focus point in focus.

My Example: F/3.5

2. On the second image, you will have more of your subject in focus, but still will maintain a pleasing background blur that separates your subject from the background elements.

My Example: F/8.0