Photographer Bruce Wunderlich has put together a great article over at Digital Photography School.
Of course it’s always possible to fix your images in post, but making a lot of adjustments means you’re bound to lose some data. That’s why it’s important to get as much right in camera as possible.
Also, if you have to take an extreme exposure due to difficult lighting conditions, make sure you always expose your subject correctly.
Most experienced photographers want control of all camera settings and don’t generally choose to shoot in auto modes for shutter speed and aperture in order to control movement and depth of field. So is there was a way to set the shutter speed and aperture and still get the correct exposure without the hassle of continually changing settings as the light changes?
There are many ways of shooting wildlife resulting in a desirable exposure, but probably one of the most overlooked ways is using the Auto ISO setting in Manual mode. To use this method, set the camera in Manual mode, adjust shutter speed and aperture to the settings desired, and then set the ISO to auto-ISO. Most cameras will allow you to set a maximum ISO, so it’s helpful to know at what ISO the images become unacceptably grainy with your camera. However, this still doesn’t entirely solve the problem of correctly exposing for those dark and light animal subjects. To solve these problems you can fine-tune the exposure by using exposure compensation.
Dark Colored Wildlife
The dark hues of some wildlife will absorb more light than the scene around them, so it becomes necessary to increase the light taken in by the camera by using exposure compensation as mentioned above. For wildlife with dark colored coats or feathers, use exposure compensation and adjust by adding light (+value). This will suffice in most cases, depending on the amount of natural light available.
Keep in mind that the wild subject is the most important component in the image, so if any aspect of the image should be sacrificed in the moment, make it the background. For really dark creatures, such as bears, start out by using a compensation of +1. Remember, don’t worry about the background. The animal is the important exposure!
Light Colored Wildlife
Conversely, for light colored animals, use exposure compensation and adjust by subtracting light (- value). The whiter color of many beautiful creatures will reflect much more light than the background will, so it helps to decrease the light the camera takes in so as not to overexpose the animal.
Correcting the background in post-production
In most cases for wildlife images, the background hues are green, yellow or blue. To enhance or balance these colors in ARC, go to HSL/Grayscale panel and simply darken or lighten the luminance for green, yellow or blue until the background exposure appears to match the exposure of the animal. A little saturation may also be added. If a little punch or contrast would improve any background flatness, one may use an adjustment brush to add some contrast and clarity to the background.
Source: Digital Photography School