DOF in Wildlife Photography

Even though photography is a creative craft, a certain amount if technical knowledge is required to lift that craft to the next level.

For me, one of the most important skills any aspiring wildlife photographer should learn is the understanding and control of the depth of field (DOF) in their images.  The ability to isolate your subject from it’s background or making sure your subject’s eyes are tack sharp and in focus is vital if your goal is to create striking wildlife images.  If you have spent a bit of time out in the field I have no doubt that you have taken images which looked great on the camera’s LCD but when you opened then on your PC you saw that for some reason the images just did not work.

A lot of the time this is because you did not pay enough attention to the aperture you were shooting at or your focal point was slightly wrong.  It has been said many many times before but to create effective images, wildlife or otherwise, you need to make sure that your subject’s eyes are in focus.  Today’s modern cameras give you up to 51 points which you can use to make sure that you hit the spot when choosing your focus points.  This is all fine and well but the margin for error, or slightly out of focus eyes on your subject, could be as small as a few centimeter.

For the purposes of looking at how your aperture and distance from your subject can influence your wildlife images let’s use the following lion image.

I took the above image a few weeks ago.  We sat about 11 meters (that’s important) from the big male lion which gave us ample opportunity to use and try different settings.

Trying to create sharp and in focus images is always something that we should aim for and this image was no exception.  The other main goal, when shooting this image, was to throw the background out of focus to keep all the attention centered on the lion’s face.  Now the catch here was, and this is the purpose of this post, to make sure that I got the lion’s entire face in focus from tip of nose all the way to the mane while at the same time throwing out the background.

Step one was to make sure that I focus on the lion’s eyes, as can by the focus point in the image on the right, but then came the important part.  I needed to choose an aperture that gives me a large enough, but not too large, DOF.  I ended up using the following settings for the above image:

• Shooting Mode:  Aperture Priority
• Aperture:  f/4.0
• Shutter Speed: 1/650
• Focal Length: 185mm
• ISO: 400
• Distance to Subject: +/- 11 meters

Before I carry on let’s juts make sure we are on the same page by looking at what all the important terms, for the purposes of this post, means.

• Aperture: This refers to the opening on the front of your lens that let’s light in.  The aperture gets measured in f-stops which can range from f/1.2, which refers to a very large opening of the lens letting in a lot of light, to f/32, which refers to a very small opening of the lens letting very little light in.  From an exposure point of view it is important to remember that the larger your aperture (expressed by a small number) the faster shutter speed you will be able to use and vice versa.
• Depth of Field:  DOF refers to the areas of your images that will be rendered sharp.  I.e. different parts of the image will be at different distances from the camera and each of these will be rendered sharp, or not, depending on the  depth of field.  DOF can be controlled by changing the aperture.  Using a small aperture (large f-stop) will result in an image where a large part of the image is in focus and using a large aperture (small number) will result in a small area of the focus being in focus.
• Focus Point: This is the exact point where you focus the camera such as the animal’s eyes.

As we were photographing this big male lion in the Madikwe Game Reserve he was kind enough to turn his head to the side which allowed me to get the shot on the right which can help in explaining how changing your aperture or distance to your subject can influence the DOF and therefore the ultimate look and feel of your images.

Now without getting to caught up in the exact details, such as how far a lion’s nose is away form it’s eyes, I uses a fantastic iPhone application to put together the following examples. PhotoBuddy allows you to enter your aperture, focal length and distance from subject and it then gives you the focal range and other useful info.  Yes yes I know that most of the time you are not going to have time to do all of that when you are out in the field but once you understand how all of this works, and with enough practice, you will start getting a feel for it and you will no doubt start creating stronger images.

Another option is to download a DOF chart which you can print and keep in your camera bag for quick reference.  If you use Google you will find many different ones but to start with you can find a nice one at DOF Master.

With all of that said, here are three examples of how you can change the DOF in your wildlife images.  For the purposes of this exercise, imagine you are shooting the lion from the right of the frame to get an image like the one at the top of this post.  Based on the variable you will see the DOF, or area which will be rendered sharp and in focus, in the red shaded area.  Here goes…

Example 1

Getting the eyes sharp is everything.  You can see that at a distance of 11 meters an aperture of f/2.8 will render the lion sharp from the tip of his nose to the top of his head.  Anything further than the top of the head and closer to you than the tip of the nose will progressively be more and more out of focus.  In a scenario like this you have a little bit of leeway in that even if the lion moved a little you will still be able to render the eyes sharp.

Example 2

In this example the aperture has been kept the same but the distance to the lion has been decreased to 6 meters.  You can see, from the red shaded area, that the DOF is much narrower leaving a lot less room for error when trying to get the eyes sharp.  In this image you will end up with the eyes sharp but the tip of the nose will be a little out of focus.  This is neither right or wrong and depends completely what your creative goal is with the image.  It is important to note that if the lion was to lift his head a little as you shoot the image your camera might lock on to the nose leaving that pin sharp but the eyes will then be thrown out of focus.

Example 3

It has always been said that f/8.0 is a good aperture to start from and here you can see why.  Compare the DOF of this image to that of the first example.  You will see that the DOF here offers you quite a bit of room for error meaning that even if you did not hit your focus point, the eyes, you will still end up with an image where almost the entire head, including the eyes, will be in focus.  This is a safe way to shoot, especially if you are trying to keep track of a fast moving subject who, if they were to move away from or towards you, will move out of your chosen DOF.  On the flip side, it will leave an image which, when compared to an image with a very shallow DOF, will not pop as much and keep the focus completely on your subject.

Make sense?  The smallest change can make a huge difference to your resulting images.  By paying attention to, understanding and using aperture creatively when photographing wildlife you are well on your way to creating better, stronger image.

A few points to remember:

• Large aperture = small number = shallow DOF
• Small aperture = large number = large DOF
• Small distance to your subject = shallow DOF (that’s why getting pin sharp macro images is quite a challenge)
• Large distance to your subject = large DOF
• Your chosen DOF works both away from and closer to you from you focus point.
• In wildlife photography you subject might move at any time so a shallow DOF is risky but can result in amazing images

Understanding DOF, and applying it to your wildlife images, is one of the most creative tools you have to make a profound differences to your images.  Check it, understand it, use it!  Next time you are lining up a shot and you have your focus locked on your subject, take a second and think what difference changing your aperture can make.

If you have any further questions or comments don’t hesitate!

Until next time.

Gerry van der Walt

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