1 : Aperture

shoot along lesson header 1.jpg

Welcome to your first Shoot Along lesson! Shoot Along is about enjoying photography, no matter where you are on your journey, from beginner to pro, and capturing your family in a way that is meaningful to you. Grab your camera. Let's get started!

This week, we'll be exploring your camera's aperture, a fundamental concept in photography. As with all the lessons in Shoot Along, be patient with yourself and enjoy the process. You will not master a new skill on the first try. Always keep in mind that all practice, even attempts that fail, are steps forward.

Aperture is the fancy name for the hole in your camera's lens. You can control how wide your lens opens on all DSLR and some point-and-shoot cameras. Aperture is measured in what we call f/stops: the larger the f/stop number, the smaller the opening (and vice-versa).

 8215190 - six aperture isolated on white background

On film cameras, aperture was controlled by rotating a metal ring on the lens, which manually cranked the lens's opening to the desired size. With digital cameras, however, it is not necessary to manually set aperture any more. Instead, you can change it by adjusting the dials at the top or back of your camera, depending on what brand of camera you use. 

Aperture controls two important things:

1. How bright your picture is.


Every digital camera has a sensor inside of it located opposite the lens hole. This sensor is the digital version of film, which is what captures the image when it comes through the lens hole as light.

The word exposure refers to how bright or dark a photo is, which is based on the concept of how much light the camera's sensor is exposed to. An image that is too bright is considered to be overexposed, while an image that is too dark is considered to be underexposed.

You can see from the illustration of the aperture settings above that if you select a low f/stop (an aperture with a low number like 1.8 or 2.0) your lens will have a wide opening when you take a picture. Because of this, more light will fall on the sensor of your camera. Using a lower f/stop, therefore, is helpful when you are taking a picture in a location that does not have very much light, such as by a window inside your house. 


When there's a lot of light available, it may be necessary to choose a higher f/stop in order to restrict how much light falls on the sensor in order to guarantee good exposure. For example, a beach with bright sand on a sunny day may require you to choose a higher f/stop (which creates a smaller hole for the light to enter into the camera through). Too much light reaching your camera's sensor will cause the picture to be overexposed and/or completely white.

2. What areas of your picture are in focus.

Aperture also controls something called depth of field. This is defined as "the zone of acceptable sharpness in front of and behind the subject on which the lens is focused." In other words, aperture controls how wide the slice of focus is that extends in front of and behind your subject. The lower the f/stop number, the more narrow the slice (and the blurrier the background). The higher the f/stop number, the wider the slice (and the less blurry the background).

depth of field.jpg

To capture a picture of your child in focus with the background out of focus, set your camera's aperture to a lower f/stop, such as f/3.5 or lower. To capture a scene with everything in focus, set your camera to a higher aperture, such as f/8 or above.

So what's the catch?

aperture example.jpg

We all love that blurry background, so why not keep our aperture as wide as possible (at a low f-stop) all the time? The answer: that slice of focus needs to be wide enough to encompass everything you want in focus! For example, let's say you have two wiggly children. An f-stop of f/1.8 may mean that your slice (or field) of focus isn't wide enough: one child may be in-focus, but the other may be too far in front or behind to be within the field of focus. In this case, you'd want to adjust your aperture to a higher f-stop to widen the depth of field so both subjects stay positioned within it.

Where to start? Begin with Aperture Priority:

Mode Dial - Aperture.jpg
  • If you have only used "Auto" mode, now is the time to graduate to "Aperture Priority" mode, which will allow you to control the aperture (size of opening in your lens). This mode is a wonderful first step away from Auto because your camera is still in charge of other important settings that affect exposure, such as shutter speed and ISO (concepts we'll be learning about within the coming weeks). To change your camera to Aperture Priority mode, turn the mode dial located on the top of your camera from "Auto" to either "A" or "Av" (depending on your camera model).

    You can see the aperture setting change by looking at the analog numbers at the bottom of your viewfinder. The aperture setting is usually the second number from the left. 
  1. To set your camera to aperture mode, find your camera’s mode dial (or mode setting) and turn it to the “A” or “Av” setting. 
  2. Press your shutter release button down half-way to activate your camera. Often, cameras will “fall asleep” and must be activated before they’ll respond to adjustments. 
  3. Put your thumb on your camera’s main dial and look through the viewfinder. Find the analog numbers at the bottom of the screen and locate the second number to the left. This is your aperture setting. 
  4. Watch that number as you turn the dial to the left, then to the right. You should see the f-stop change as you turn the dial. 
  5. You’ll also see the first number change. This is the shutter speed setting that your camera is adjusting to match the aperture setting you choose. You don’t need to worry about changing this number yourself when using Aperture Priority Mode. 

Once you've experimented with using Aperture Priority mode, noting how changing the f/stop increases or decreases the amount of blur behind your subject. 


Experienced? Try this challenge:

  • If you already shoot in manual mode, take this week to push your lens(es) to the limit. Try shooting at both the lowest and highest apertures your lenses offer. How does this affect the moments you are capturing? Does shooting at extremes provide a more journalistic tone or a more artistic tone? Does it make you change the way you normally approach documenting your family?

We will be exploring Shutter Speed and ISO, the other parts of the "Exposure Triangle", in the next two lessons. Understanding these interrelated concepts is the best way to improve your pictures - it puts the pieces of the puzzle together! If you're an experienced photographer who is already shooting in manual mode, you should find this refresher a useful way to test conventions against the technical limitations of equipment, forcing you to re-examine your "go-to" settings.


Creative Prompts

Remember... Shoot Along's purpose is two-fold. First, it's created to help you learn and grow in your photography skills. Second, it will remind and encourage you to consistently capture your children through photography. If and when the weekly lessons have skills that you're already familiar with, practice them anyway! Use the opportunity to push yourself further as you document your family's life through your lens.

Below are a few prompts if you're looking for some specific ways to dive into this week's lesson:

  • Using a low f/stop, capture your child's hands as he is involved in an activity. 
  • Using a low f/stop, capture the details of your child's face or clothing, blurring out the background
  • Using a high f/stop, capture your child in their bedroom with all the details of the room (toys, bed, furniture) in focus
  • Using a high f/stop, capture your child outside keeping the entire scene in focus

Share your images!

Have you tried this week's lesson? We'd love to see the results! 

Share an image and get feedback in our private Facebook group. The group is part of your subscription and a wonderful extra resource.