Best Cameras for Wildlife Photography:

Learn about Exposure

Written by me Bryan Conners who has been playing with camera's and photographing wildlife longer than I care to remember!

"What the human eye observes causally and incuriously, the eye of the camera notes with relentless fidelity."
Berenice Abbott
On this page I explain all about exposure, the most important aspect of wildlife photography

Exposure in bird and wildlife photography is a challenge, light constantly changes, the subject is often moving and fast shutter speeds are usually called for. When working with nature you rarely get a second chance to take another image if the first one is not exposed correctly. I explain on this page the three settings that control exposure, shutter speed, ISO and aperture.
Shutter Speed.

The shutter speed is a measure of the time that the shutter curtain is open and allows light to strike the image sensor.
Exposure tip!

The shutter speed can at times be slowed right down if you are working in dull conditions and don't want high ISO settings. I often slow the shutter down to 1/300 and fire off 5 frames in the hope that one of them will be sharp, even small birds stop moving sometimes.
What shutter speed do you need?

The basic shutter speeds range from 1 second to 1/2000 second. When you move up or down one number (called "one stop"), the amount of light allowed to strike the sensor is either doubled or halved. For instance, if you change your shutter speed from 1 second to 1/2 second, the amount of light striking the sensor will be cut in half. If you change your shutter speed setting from 1/2 second to 1 second, twice as much light will strike the image sensor.

In addition to governing exposure, the shutter speed impacts image sharpness. Very fast shutter speeds freeze the motion of a subject to ensure it is sharp, essential when photographing wildlife.

When slow shutter speeds are used, a moving subject will appear blurred. (Note, too, that the slightest movement of the camera can also make for a blurry image.) Birds and animals can move very fast, so a shutter speed of 1/1000 second is usually the minimum requirement for a sharp image. Larger animals are often much slower and require slower shutter speeds.

Shutter speed top tip: Use a Tripod!

Wildlife and bird photographers most often use long lenses to magnify the size of their subject. Unfortunately with long lenses blur related to lens movement is a problem. Using fast shutter speeds can avoid this but due to other constraints to do with exposure this is often difficult. Using a tripod can reduce lens movement and allow you to use slower shutter speeds.

Using a Tripod can help reduce shutter speed

The aperture is the adjustable opening in the lens that allows light in to strike the image sensor. Apertures are sometimes referred to as f-stops.

The most common settings are f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger numbers represent smaller-diameter openings, and these smaller apertures allow less light into the camera to make an exposure.

Making a one-stop shift in aperture will halve or double the amount of light that strikes the sensor. For example, if your aperture is f/8 and you move to f/11, you will reduce the light by half. Moving from f/11 to f/8 will double the amount of light that reaches the sensor.

The f-stop also controls the amount of the scene, from front to back, that will appear in focus. A wide aperture like f/2.8 allows for a very shallow focus depth, while a narrow aperture like f/22 allows for much more of the scene to appear in sharp focus. This phenomenon is referred to as depth of field, and it is an important tool in creating effective images.

Depth of field is also affected by the focal length of the lens. Telephoto lenses compress the image and make a shallower (narrow) depth of field with less of the image in focus. A wide angle lens will show a wider view and give more depth of field.
Bird image with blurred background or bokeh
Aperture top tip: Blur the background!

Use large aperture settings F/5.6 or less to blur the background of your target subject. This is especially effective in bird photography and is referred to as Bokeh. This image of a Crested Tit was photographed with aperture at f/5.6, the bird is in focus but the background is blurred. This makes the subject stand out.
A list of base settings needed for Wildlife and bird photography.

As a starting point you can set your camera to the following settings:

Aperture: A large as the lens allows: f/4
Shutter Speed: 1/1000
ISO: Auto
White Balance: Auto
Focus Mode: Al Servo or continuous focus
Auto Focus Point: Centre only
Picture Style: Natural
ISO and how its used when photographing wildlife in changing conditions.

The ISO (an acronym that stands for International Standards Organization) is a setting that determines the light sensitivity of the image sensor. Standard ISO settings are 50, 100, 200, 400, 800, 1600, and 3200.

If you need more light for a proper exposure, adjust your ISO to a higher numerical value. The side effect of increasing the ISO is more noise (dots and colors in the image, a digital equivalent to film grain).

Most wildlife photographers try to keep their ISO setting as low as possible but it's more important to keep your shutter speed fast enough for the animal you photographing, you are better with a sharp but slightly grainy image that a smooth image which is blurred.

Let's look at a scenario that will help you to better understand how changing the ISO can help you meet your image objectives.

Imagine that you want to shoot a front-lighted subject using a 1/2000 second shutter speed and an aperture of f/4. The sun is setting, so you will need more light for a proper exposure. The maximum aperture on your lens is f/4, so you cannot choose a wider aperture to let more light into the camera. You cannot reduce your shutter speed because you want to ensure that your fast-moving subject will be sharp. Your only other choice is to set the ISO to the next higher number.
ISO can allow you to get a shot when otherwise you could'nt
ISO top tip: Don't be afraid to turn it up if needed!

Noise associated with high ISO degrades the image but if you need to use it don't be afraid to go for higher settings. Modern processing software can remove a lot of the ISO noise but it cannot do much with a blurred image or an image which is too dark and has lost detail. This image of a Goosander required ISO of 4000! as it was under trees and very dull. Adobe Lightroom removed most of the noise and I was very happy with it. I usually aim for ISO around 800 or less.
Camera mode and Auto ISO

Most wildlife and bird photographers work in what is called manual mode. This allows the setting of shutter speed and aperture to be set exactly how it's needed. ISO however is usually set to Auto mode which means that regardless of changing light conditions it will adjust and ensure the exposure is correct.
The term "bracketing" refers to the practice of making a series of exposures using slightly different settings to improve the odds of getting a "correct" image. The camera can be set to take a series of images at slightly different exposures on the basis that at least one of them will be exposed correctly. This is a practice that I recommend beginners to use until they are confident with getting a correct exposure as you may not get a second chance to photograph an elusive bird or animal.
Al servo is used for wildlife photography
Bracketing top tip: Bracketing has a downside!

If your photographing moving birds or fast moving animals I would not recommend bracketing. Typically when you hold down the shutter button the camera will take three images then stop although some higher end cameras can be set to take more. If the animal is moving it's more than likely you will want more frames than three and sods law is that the one that's not exposed quite right is the one of the animal in the correct position.
Take a look at my other articles below....

Bird image with blurred background or bokeh
My guide to exposure in wildlife photography. Learn about the three crucial settings.
Al servo is used for wildlife photography
Understand the technical features that make a good wildlife camera.
No photography jargon on this page
Choose the best camera for wildlife photography by reading my no jargon guide.
Fast camera autofocus is essential to focus on moving birds
The top six essential things that every camera must have in order to take quality images of birds.