How To Take Charge Of Depth of Field In Your Photography

Understanding how to control depth of field in your photographs is one way to take creative control of your images.

When an image has a large depth field it means that everything from the foreground to the background is in focus.

A shallow depth of field is when only a portion of the image is in focus. This can mean anything from the background being slightly soft to only a razor thin slice of the image being sharp.

As an artist you don’t always want your images to appear exactly as your eye saw the scene. You want to draw the viewer’s eye to something in particular, to emphasize one thing over another in an image.

So, how do you do that? I’ll show you …

Depth of field is controlled by three things:

1. Aperture

Aperture is the size of the opening through which light travels to your camera’s sensor and it is expressed in f-stops.

The smaller the f-stop number the larger the opening. That’s kind of confusing isn’t it? It’s because the f-stop number is actually a ratio. But I don’t want to get into too much mathematics here, just remember it’s like a fraction and 1/2 is bigger than 1/8 so f/2 is bigger than f/8.

aperture

The larger the opening the more shallow the depth of field. In other words the amount of your scene that will be sharp, measuring from the object you focussed on, is smaller.

These two images illustrate the effect of aperture on depth of field. (Please click on the images to view larger versions.)

Victoria Legislature Totem
35mm at f/20: Everything is in focus

Big Balls at Seattle Center
35mm at f/4.5: Only the ball in the foreground is in focus the rest of the image is soft

2. Your lens

Just to make it even more complicated, all this changes with every lens you have!

So the setting of f/4 ,for example, is actually different depending on the focal length of your lens. f/4 on a telephoto lens like a 200mm is actually a larger opening than f/4 on a 50mm lens.

That means when you use your telephoto the depth of field is smaller than the same setting on a mid-range lens. (Remember large opening means shallower depth of field.) Conversely f/4 on a wide angle lens has a much bigger depth of field than a mid-range lens.

Cherry Blossoms
250mm at f/5.6

With the telephoto lens at f/5.6 the depth of field is extremely shallow with only the blossoms in the immediate foreground in focus. I bet you didn’t know there is an ugly blue house behind those flowers! Making use of depth of field is how I made the house invisible.

New Orleans Street Busker
20mm at f/5.6

With a wide angle lens at f/5.6 the depth of field is pretty big. In this case the building behind the musician is totally in focus. It probably would have been a better image if I had used a telephoto lens and moved farther away, but that was not physically possible unfortunately.

3. The distance between you and the subject

Remember the area of the scene that is sharp is measured from the subject you are focussed on. So if you are making an image of a cityscape and the whole city is miles away, you can get away with a larger aperture opening and everything will still be sharp because the whole subject is in the distance.

On the other hand if you focus on something that is a few meters away and part of your scene is miles away then you will need a small aperture if you want everything to be sharp.

A few more examples to demonstrate depth of field:

Convict Lake, California
16mm f/22: Everything is in focus
Spring Tulips
70mm f/4.0: Subject in focus, background totally out of focus
Hatley Castle Japanese Garden, Victoria, BC
85mm f/11: Subject in focus, background soft but still recognizable
Fly and Daisy
250mm f/5.6: Razor thin area only is in focus

When you are photographing be conscious of how you want the background in your image to look and take control of the depth of field!

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Comments

    • says

      Hi John, I know I think depth of field is one of the hardest concepts to learn. And, you are right, there seems to be many ways of explaining it many of which contradict each other. Thank you very much for your comments, I appreciate it.

    • says

      Hi Michael, I think it depends on the camera. When I used to use a compact camera in auto mode, my camera always chose a large aperture with small depth of field. I don’t know how the cameras choose these settings. But that is one of the best reasons to get out of auto mode and start taking control of what you want the image to turn out like instead of letting the camera make the decisions. Try using aperture priority and see what your camera does then. Thank you very much for contributing your comments, they are always welcome!

  1. Berta says

    Anne, all the depth of field tutorials that I have read before only cover the lens aperture part, but they seem to neglect the fact that the same aperture gives you different depth of field depending on the focal length, I did learn that by experience. And for me it is very important, that has been the reason that have made favour some lenses over others over time. Thanks for putting it all together in such clear way!

    • says

      Thank you for your great comments Berta. I too have discovered this with experience and often choose one lens over another just to get the depth of field and perspective I want. I’m glad you enjoyed the post.

  2. SATISH says

    ANNE, I AM A NOVICE COMING OUT OF THE AUTO INTO MANUAL MODE. I HAVE BEEN TRYING TO GET AN IMAGE WITH A SHALLOW DOF WITH MY NIKON COOLPIX 4500 BUT HAVE NOT SUCCEEDED. WITH A LARGE APERTURE SET IN MANUAL MODE, ONCE I ZOOM IN, THE APERTURE CHANGES AUTOMATICALLY SO THAT I DON’T GET A BOKEH. IF I DON’T ZOOM IN THE EXPOSURE HAS TO BE MANAGED. DO I NEED TO USE AN SLR CAMERA IN THIS CASE TO GET THE RESULTS OF A PROPER DOF? AND YOUR EXPLANATION IN YOUR BLOG IS VERY PLEASING, SIMPLE & DETAILED TO SAY THE LEAST.

    • says

      Hi Satish, sorry for the delay in my reply. If your camera has an aperture priority mode, that’s where you want to be. Then you can set the aperture for the largest it can be (say 2.8) and the camera will then calculate the appropriate shutter speed. I just looked up your camera and it does have aperture priority. You hold down the “mode” button while turning the command dial until the mode “A” displays in the lower left corner of the LCD. Then, once it is in aperture mode, you use the command dial to select the aperture. I hope that helps!

      By the way, I found that information in the user guide here:
      http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/4500/index.html

  3. Luffy says

    Thank you very much, Anne.

    I’m still a beginner and your topic is the best that i’ve ever read! No need for blah blah blah, just direct to the point :)

  4. Sherry Hogue says

    Thank you Anne for your excellent article and beautiful photos on DOF.
    I shoot with a crop sensor camera and wonder when choosing a lens for a particular DOF do I need to take into consideration the crop factor of my camera? I am assuming your photos were shot with a full frame camera.
    Thank you Anne for sharing your knowledge and wonderful adventures with your photography. You are most encouraging to this beginner.

  5. says

    Anne:

    I knew about 90% of this tutorial, yet it was a good refresher course. I especially liked your pairs of comparison photos. I shoot about 85% of my shots in aperture priority on my old, but trusty, Canon 40D. The rest of the time I’m in sports mode trying to get birds in flight.

    Your website has been in my favorites bar for two months. I appreciate all that you do. You have a generous spirit.

    Gratefully,

    Richard Havenga – Author of blog: “Walk With Father Nature

    http://walkwithfathernature.blogspot.com/2015/04/like-prayer.html

  6. says

    Thanks for explaining this “hard to get your head around” topic in such a straightforward and easy to follow way. I will send a link from my facebook as I am also often asked this question. Not everyone has all the different types of lenses for the different settings, such as macro, tele, wide angle. And so they end up photographing insects with a telelens, for example, and can’t figure out why only part of the creature is sharp.
    Greatly appreciate your generous sharing.

  7. says

    Excellent article Anne. The fstop issue can be awfully confusing to beginners – why large aperture with small fstop? The way i got my head around it was to learn a bit more about light and what was happening physically when you change fstop. In the end I resolved my confusion with the understanding that the iris actually BLOCKS light from reaching the sensor. It is a non issue then. If I want to block a lot of light then I select a large fstop. Conversely, if I want to block a small amount of the available light, I select a small fstop.

    I’m still working on a simple explantion for how this affects depth of field!

  8. Annie Honjo says

    At last – a simple, easy-to-comprehend explanation of why the f-numbers get larger as the opening gets smaller!! Why haven’t I read anywhere else that you can equate it with fractions! Great article, Anne – very clear and well-illustrated.

  9. Daniel Martin says

    Brillant! Your explanation is simple and the supporting photo helps greatly visualize the principles explained by your text. I might be experienced but your tip was very refreshing. I tend to forget some basics as I grow older :)

  10. says

    Hi Anne – Thank you for clearing this up. I had no idea that different lenses would affect the depth of field. I finally learned to use a large aperture to blur the backgrounds, but then I would use other lenses and I just couldn’t get the blur – now I know why.

  11. says

    Hi Anne,

    So well explained, with many of us being visual which really showed me why close-ups with certain lenses have become my favorites.

    Much appreciate your articles and wishing you “Happy Shooting” and fun in your travels !

  12. George Thomas says

    Thank you for your very clear explanations Anne, I am understanding these concepts more and more everyday and am finding it much easier to explain to other folks that are just setting out on their photography journey. It helps when one is able to share picture taking with someone that is willing to learn more, experiment more and just plain, enjoy finding the beautiful things in life that photography helps you see that you may never have noticed before.

  13. Shutter Snail says

    Hi Anne,

    I have been following your articles for a few series already and you have made such a tricky topic remarkably easy to understand. I will be greatly appreciated if you can incorporate the calculatation of the hyperfocal distance in relation to the depth of field.

    Thank you very much in advance.

    Cheers!

  14. says

    You’ve repeated one myth about DOF. In fact, changing focal length does not change DOF. The same composition shot with two different focal length lenses at the same aperture will produce the same depth of field. This is easy to demonstrate: create the same composition at the same f/stop with two lenses. What will change is the relationship between near/far elements in the scene.

    It’s easy to think that changing focal length changes DOF when the image comparison is not apples-to-apples. When you fill the frame with the same content, DOF at any aperture is identical.

    • says

      Hi Denis, I disagree. The way you have explained it, you are using “the same composition”. That means you have two variables: the lens and the distance between you and the subject. In my example I have only one variable being the lens. To me it makes more sense to understand what the difference in depth of field is going to be when I stand in the same spot and switch lenses. That’s practical. The way I look at it, if you use a long focal length, say 200mm, at f/5.6 you can easily get a nicely blurred background. Good to know. But if you use a wide angle lens, and move way closer, you’d have to be millimeters away from your subject, which is not practical and often not possible because the lens wouldn’t be able to focus that close. When I understood the difference in the depth of field I would be able to create with my lenses, it made a big difference to my photography, so that’s how I teach it. Most people don’t want to do mathematical calculations of hyper focal distance. They just want to know what’s going to happen when they switch lenses!

  15. Susan says

    Just bought my first new lens for my Nikon D3200. It is a 300 zoom. Hadn’t even had time to discover that with it, f5.6 would give me a different depth of field than with the standard lens at the same f stop. Being able to understand this and think it through will help me to make better choices when it comes to using my lenses. Thanks Anne.

  16. Luiz Muzzi says

    Your blog/newsletter is much better than hundreds or thousands out there…
    Your way of explaining difficult subjects in a simple manner really pleases me.
    I am already a fan of your writing style and your photos, even your personality (and I got to know your site very recently). I am feeling compelled to buy your e-books, something I have never done.
    Regards,
    Luiz Muzzi

Trackbacks

  1. […] How To Take Charge Of Depth of Field In Your Photography – quite simply one of the best articles I’ve ever read that takes the reader through the technicalities behind controlling depth of focus.  This powerful tool in the photographer’s arsenal is the result of a complex set of relationships that envelope focal length, distance to subject and aperture size, and Anne McKinnell delivers a very easy to digest article that removes the mystery behind it all. […]

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