Seeing in Depth of Field: A Simple Understanding of Aperture

Seeing in Depth of Field: A Simple Understanding of Aperture


Photography can be simply defined as: painting with light.

When you are painting with light, you are creating a story in a split second. That’s what photography is all about. Technically, your camera is measuring the light in the scene, and you are telling it how much of that light you want to use to create a properly exposed image. This becomes your story.

There are three main settings used to control that light; Shutter Speed, ISO and my favorite, Aperture. Each of these settings has its own individual way of measuring light. When all three are balanced correctly, you create a proper exposure.

1 Aperture Range 3265

Though each of these three settings measures light, they also have unique characteristics that create artistic qualities in your photographs. By understanding them, you have control over the full story you want to tell.

Shutter speed captures movement or freezes it. ISO helps control how sensitive your camera is to the available light in a scene. Finally, the aperture creates depth of field. This is where the real story comes from; it is with aperture that you control what is in focus, and what is out of focus.

As a photographer, how do you decide what you want your viewer to focus on? How do you create a story? That’s what aperture is all about, and that’s why I love it.


Aperture is located in your lens, not in the camera body. The lens opening expands and contracts to control light. By selecting a specific aperture size, you are telling the lens how much light you want to hit, and register on, the sensor.

It is very similar to how the human eye works. Your pupils expand and contract based on the available light in the scene. Like when you first walk into a dark movie theater. At first you can’t see, then your eyes adjust. Your pupils expand, allowing your eyes to see as much light as possible in the dark room.

Again, when you go outside on a sunny day, at first it’s too bright to see. Your pupils adjust by contracting, letting in less light. Your lens aperture works the same way. Changing aperture settings is like your pupils dilating or contracting.

The size of a lens aperture is measured in what we call f-stops (fractional stops). Just like all settings on a camera, there is a general range.

2 aperture range2

The numbers aren’t necessarily important to memorize. What’s important is to see the range in the settings. Here is the trick; the smaller the f-stop number (like f/1.8), the larger the aperture opening. This means more light will enter through your lens at once, and vice versa. The larger the f-stop number (e.g. f/22), the smaller the aperture opening, and less light will enter your lens.

Think of these f-stops as fractions. Just replace the F with the number one. 1/4 of a pie is much more than 1/16 of a pie.

A quick note: Not all lenses are built the same. Different lenses have different apertures. Some lenses have a wider range and some have less. Standard lens will range from F3.5–F22. Specialty lenses go as low as F1.2 or more. See: What the Numbers on your Lens Mean for more on this.


Here is where it gets fun. While measuring light, when the lens expands and contracts, it also measures depth of field. Again, your eyes do the same thing!

As you look at the screen to read this, these words are mostly in focus to your eyes. In your peripherals, you can see other things, but they aren’t in focus.

Notice, your hands on the keyboard, they are in the foreground, and perhaps a bookshelf is in background. You can see them but they are not in focus. You are seeing in depth of field.

A great photograph does just that. It captures a foreground, a mid-ground and background. By setting your aperture you are controlling which of these areas is in focus. It is all based on your intention, your story.


With your camera’s focal point (that little square in the middle of your viewfinder), you focus on a particular part of the scene. This point becomes the sharpest part of your image. There is an area in front of that point in focus, and an area behind it in focus as well. The distance from front to back that is acceptable focus is considered your depth of field. You decide what is acceptable by choosing a specific aperture size.


This is a story about a monkey on a cliff. The bushes in the foreground and the temple on the cliff in the background are out of focus. They are out of the depth of field. This brings your attention to the focal point; the monkey in the middle (no pun intended).

Remember, the lower the f-stop number, the bigger the opening, the more light comes through the lens. This means less of your scene is in focus and you have a shallow depth of field. The opposite is also true. The larger the f-stop number, the smaller the opening, the less light comes through the lens. In this case, more of your scene is in focus and you have a greater depth of field.

Simply put, the larger the f-stop number, the more will be in focus. The smaller the f-stop number, the less well be in focus.


As you lock your camera’s focal point on a specific spot, that spot creates a focal plane. Everything that is the same distance away from the lens is on the same focal plane, and will be in focus.

4 focal plane explained

At a shallow depth of field (low number), the focal plane is very thin. As your depth of field becomes greater (high number), the focal plane becomes deeper.

Here is the same scene photographed with different aperture settings. Notice that the depth of field changes how much of the image is in focus.

5 aperture example

At f/2.2 only the sunglasses are in focus. At f/5.6 the hat is also in focus. By using f/8.0 you can start to make out the trees in the background. Finally, at f/22 everything in the image is in focus.

Which one tells the best story? You as the photographer, get to decide.


Now that you’ve got a good grasp on the basics, it’s time to play! Here are some great tips to start your practice.

Set your camera to Aperture Priority mode. You will have full control of the aperture, without having to worry about proper exposure. This way you can just focus on depth of field. It’s a great way to fully understand what your lens is doing as you change your aperture settings.

Pick a subject or scene, and stick with it. Photograph your scene from many different angles. Choose different parts of the scene to focus on using the full range of aperture settings.

Use these guidelines to capturing depth of field in different scenarios:

6 Aperture Range 9748

When shooting single subjects, like a portrait of a child, it is best to use a lower f-stop like f/1.2-f/2.8. Creating a shallower depth of field brings attention to the subject’s face, which is always most important in a portrait.

7 Aperture Range 2145

When shooting a small group of people (2-5), choose an aperture of f/4-f/8. This, being a slightly deeper depth of field, guarantees that everyone in the group will be in focus.

8 Aperture Range 6150

Any time you have a wide-open scene, for instance a landscape, and you want all of that landscape in focus, choose a setting above f/10.

These are just guidelines. Photography is a form of art. Be creative, and remember, it’s all about telling a story.

What story do you want to tell? Share your images here and show how you’ve used depth of field to create a great story.

All Images in this article are © 2015 Danielle Werner and DEW Imagery & Design


Read more from our Tips & Tutorials category

Danielle Werner is a free-spirited photographer, designer and retoucher, on an endless journey around the world. She is also a passionate writer and educator who teaches photography workshops wherever she goes. Read Danielle's inspirational travel stories at, and check out more of her adventure and lifestyle photography at DEW Imagery & Design.

  • I agree with Edmund. When you are looking through that viewfinder, pay attention to every inch of that frame and decide what is most important to focus on, Then create a composition that’s intriguing to the focal point. I love the foreground interruption that draws your eye to the flower!

  • Check out this whole thread, awesome macro’s of tiny creatures! This is great. The eyes are the focus, and there is balance with the colors against the neutral background. I love it! Maybe off set the focal point from the center of the image?

  • Janet

    Thanks! Does it not have a ‘see more’ below what you can see? I do almost always aim for the eyes, in this shot I wanted the eyes and the proboscis- in the printed/full rez pic you can see the line where the 2 sides joined. It’s one of those things that not everyone knows and I like to show.

  • Shiralee Merrick

    Thanks. I had no idea this would come out like this when I took it as I ended up with my camera sitting on the concrete path and only got a vague idea that the mantis was actually in the frame.

  • Roger Boeken

    a missed opportunity : the focal plane is not vertical but perpendicular on the line in your illustration connecting the camera and the focal point. In other words the focal plane is always parallel to the sensor in the camera. This is very important when you want the person as shown in your picture to be in focus from head to toe.


  • Janine Wilson

    I have finally understood aperture! I just want to thank you Danielle. I have read so many articles and books on how to get to grips with aperture, yet, this article explaining the pupils of our eyes and the way aperture correlates to this simple understanding of contracting and expanding is something I believe has been fixed into my memory that will make my photography so much easier and fun to explore – now that I understand. Great article.

  • Janine! This makes me so happy! I have a blog article coming out tomorrow that truly exemplifies my feelings towards readers like you! All I want to do is inspire others in ways that makes it easy and fun to learn photography! Check out the article tomorrow here: And thank you for your great comment! Send some new pics when you capture something you love!

  • I see them! OMG, I love these bugs and that gecko (or whatever it is!) Those eyes are awesome Great job Janet!

  • Janet

    Thank you! *blush* It’s a chameleon from a local pet store 🙂

  • David Werimo

    Help full tips for a beginner like me. am beginning to love photography and theres still alot to learn.thanks alot.

  • I’ve always though “Stopping down” was a bad term to use anyway; confusing jargon old hands use that confuse beginners. When you’re referring to stops, you are talking about a number. So down would logically be less of said stops, it’s easy to see why people get it backwards. Even when they know a higher number is smaller opening if they haven’t heard the term they may be wondering “Does he mean the number down or the amount of light down?”

    I try to stick to telling somebody to “Close down the aperture” to help people understand what it is they’re actually doing to the light passing through the lens.

  • Coleen Cappelli

    I love your pictures Janet! I recently purchased my first DSLR because I have been really interested in getting close up images of flowers or nature. I was able to buy a kit that included a zoom lense, which is awesome because I want to be able to shoot images of the moon as well. I wasn’t able to purchase the macro lense that day, but now seeing your pictures makes me even more excited to get it!! Thanks for sharing!!

  • Coleen Cappelli

    I have a canon and the lens that came with it is 18-55 mm. It only goes to f/3.5, as far as I can tell – what kind of specialty lens will allow me to go as low as f/1.8?
    Also, I’m guessing that the more I zoom in on an object the f-stop will adjust automatically to a higher number?

  • astungkara

    you put my local area as the featured picture…
    I know them taken in Tanah Lot and Uluwatu area, BALI…..

  • M

    How does distance of camera to subject impact depth of field? I have a standard lens f3.5-f22. It doesn’t go as low as f/1.8 and I have trouble shooting shallow depth of field unless I’m really close to the subject…..

  • in_awe

    It is important to remember that cameras typically you allow to select the aperture, but the viewfinder is still showing the image with a wide open lens up to the instant the picture is snapped. To see how the picture will look AT THE SELECTED APERTURE many cameras have a DOF preview button. When you press it, the lens actually is set to the selected aperture and what you see for DOF is what you’ll get in the actual photo.

  • Hi M- so sorry I didn’t see this comment earlier. This is a GREAT question. The relative distance between your camera, your subject and your background are extremely important to the “effect” that depth of field can offer your final image. For the most impact (especially when you can not go lower than f3.5) bring your subject closer to the camera lens and further away from the background. Hope this helps!

  • Yes Coleen, you are correct. The more you zoom the lens control your lens has therefore it can not function as well at a lower aperture number (deeper depth of field). Get yourself a nifty-fifty lens. Canon makes these F1.8 simple prime lens that will rock your world! They are less than $100 bucks now on amazon and they will teach you so much about the world of aperture!

  • Kathleen M Pearson

    This is a great article – thank you! I use a point-and-shoot camera. Are there any settings you can recommend to help show depth/distance? I take photos on top of a 40′ high bluff and if I shoot straight down (showing different “shelves” of the bluffs) to the shore, the photos don’t reflect the distance. Thoughts?

  • This is a really big challenge! I would love to see some of your images 🙂 I think the first thing that comes to mind is that you want as much clarity and color definition as possible to truly show off the textures of the scene. Also when emphisizing distance and scale, its important to have relativity. So having a human in the shot to show how small they are (or far away) is an example.

    Check out this guy, Gabriel Scanu. His work is amazing. Does anyone else see this post and have any suggestions?

  • Kathleen M Pearson

    What a beautiful shot! Here is one I took earlier today. I stood at the edge of the bluff and shot straight down. There isn’t much light so I ran this through PE to bring out the colors and contrast. There are two “shelves” before you get to the water. I can’t seem to make them stand out. Thoughts?

  • Fred Odede

    With guidelines from this article,I managed to shoot this…your thoughts?

  • Sallie Anthony

    This is the easiest and best explanation of depth of field. Wish I’d had this article when I started photography. I would have understood DOF immediately

  • Im so glad this has helped you!

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