Taking Advantage of Auto ISO
If you Google “best camera settings for bird photography” you will discover there are about as many different opinions as there are birds in the world. Bird Photography is an extremely challenging photography genre with so many variables that it is impossible to declare what ‘the perfect’ settings are. Inevitably you are aiming to use a shutter speed that captures the motion you are trying to convey – whether you are aiming to freeze the bird’s motion altogether, or leave a little blur on the wing tips. You will select an aperture that will capture as much of the bird in focus as possible, while at the same time produce a nice blur to seperate the bird from the background. Of course we will always aim to use the lowest ISO setting possible. No pressure – you need to figure all of this out in the brief moment that a bird presents itself!
One camera feature that you can use to help eliminate the complexity of bird photography settings and simplify the process, is Auto ISO. Some photographers will swear by Auto ISO, while others hate it. Many others simply have no idea how to use it. I’ve found that since I started using Auto ISO the number of keepers I come home with each shoot has increased. Auto ISO works quite differently camera to camera and taking the time to get to know what Auto ISO features you camera supports can go a long way to improving your bird and wildlife photography.
Auto ISO Settings
In situations that evolve quickly, Auto ISO is an advantage that allows you to concentrate on focussing and composition while the camera manages exposure. Depending on your camera, there will be a few Auto ISO options for you to choose from, with the most basic option to simply select the minimum and maximum ISO values you wish the camera to use. Many entry level cameras may have no additional options available and the benefits of this basic version of Auto ISO are quite limited but can still prove to be quite valuable.
Minimum Shutter Speed – This feature allows you to set the minimum shutter speed to be used when Auto ISO is turned on. This is used in conjunction with Aperture Priority mode where you can select the desired Aperture and the camera will select the shutter speed and the ISO values. The camera will continue to raise the ISO value to maintain the minimum shutter speed until the max ISO value is reached, at which time the camera will allow the shutter speed to drop below the shutter speed minimum value. All cameras are not created equal however, and some cameras will allow you to select a minimum shutter speed of 1/8000th of a second while others are capped at 1/250th of a second, which is not totally suited for bird photography.
Auto Shutter Speed – In addition to being able to set the minimum shutter speed, many cameras will also allow you to set the shutter speed to auto while using Auto ISO, which, once again will differ from camera to camera. Some cameras will select which ever shutter speed is required to get a correct exposure, while other cameras will restrict the Auto shutter speed to the reciprocal value of the lens. That is, when using a 600mm lens the minimum shutter speed will be 1/600th in Auto ISO.
Putting Auto ISO to Work
Now that we have discovered the possible setting for Auto ISO, let’s have a look how it will be used.
Auto ISO and Manual Mode – In Manual exposure mode with Auto ISO turned on, we can manually set the shutter speed and aperture and the Auto ISO will increase or decrease the ISO to a value required to achieve a correct exposure. Using Manual mode with Auto ISO is ideal for bird and wildlife photography with constantly changing lighting conditions.
One drawback, is that slightly older or entry level cameras set to Manual mode with Auto ISO on will only adjust the exposure value to produce a middle grey or mid brightness exposure and do not offer exposure compensation in manual mode to adjust the exposure for tricky lighting conditions. This can often leave your bird images underexposed and require you to increase the exposure in post processing which can also magnify any noise in the image introduced by using higher ISO values.
Auto ISO and Aperture Mode – Cameras that allow you to set faster minimum shutter speeds in the Auto ISO settings using Aperture mode may prove to be a better option if your camera is lacking the ability to adjust Exposure Compensation in Manual mode with Auto ISO. In Aperture Priority mode with Auto ISO set with a faster shutter speed, you only need to select the aperture you require and the camera will select an ISO value suitable to maintain the minimum shutter speed setting.
You will still be required to keep an eye on your shutter speed as when the camera reaches the maximum ISO level programmed it will begin to decrease the the shutter speed to maintain the correct exposure values. Using Aperture priority mode with Auto ISO and a high shutter speed also has the added advantage of being able to use Exposure Compensation for the more challenging lighting conditions.
Managing Noise at Higher ISO Settings
As photographers, we always strive to use the lowest ISO value possible to eliminate the introduction of noise into our images. Shooting birds in low light conditions will require higher ISO values that will introduce noise into your images. Knowing how to best manage that noise can lead to a higher quality of keepers.
- It’s always better to shoot at a higher ISO with noise than it is to shoot at a slower shutter speed that prevents you from capturing a sharp image
- If you ensure that your exposure is correct or slightly on the bright side, you will need to make fewer exposure adjustments in post processing which can amplify the effects of noise.
- Spend some time getting to know the maximum ISO value you can use on your camera with a noise value that can be adjusted satisfactorily in post processing and still produce a high quality image.
- Use additional software such as Topaz DeNoise AI which provides superior noise reduction and sharpening than can be achieved in Lightroom and Photoshop.
Take some time to get to know the Auto ISO features in your camera and determine how it can be used to improve your responsiveness to the changing conditions when you’re out in the field.
If you would like to have a look at my Australian Bird Photography project – Australian Birds – The collection is constantly growing and improving!
Looking for a bit of motivation to get your project underway? Here are some up-coming Photography workshops you may find valuable:
10th - 13th Sept. - Capertee Valley
13th - 15th Nov. - Kiama