Nick Dungan
Nick Dungan is an award-winning motorsport photographer, based in the UK. He has more than eight years of experience shooting national and international events, and works with numerous prestgious clients including McLaren, Aston Martin and Nissan. Visit www.nickdungan.co.uk. Autofocus is a huge part of delivering great motorsport photography. The ability to capture your subject, whether it is stationary or moving at 200mph, can call for a range of tricks, techniques and skills.
1 Assess any movement I like to use single shot or continuous autofocus. If you know that your subject won't be moving then single shot autofocus will generally give you more reliable and accurate results. This is great for posed portraits or fine detail shots. If your subject is moving even a little bit (a driver sat in a car, for example) then continuous autofocus will give you the best chance of capturing a focused image. 2 Choose a focus spot layout The subject you are shooting will generally dictate the best Focus spot layout. If you are shooting a large subject, for example, then a multi spot or active mode will work well. If you require the precision to pick out a particular element of the frame (for example the eyes of a driver through the visor) then a single Autofocus point is often the best bet. 3 Consider using manual focus Sometimes even the most advanced autofocus systems can get it wrong. In such instances good old manual focus is there to help. I often find that when I’m shooting very shallow depth of field on my 85mm f/1.4 or 200mm f/1.8 lenses the camera can’t quite get the focus right on driver portraits. Sometimes all that is required is to knock the focus ring back/forward a fraction and bring the front eye into focus.
4 Use the focus limiter On long lenses the amount of time it takes them to work from their closest focus distance to infinity can be considerable, especially when they miss focus and start to seek/hunt. All long lenses have focus limiters that allow you to increase the minimum focus distance (or reduce the maximum). The result is that when the lens does seek or hunt it will take less time and you can get back onto your subject quicker. This can be useful in situations where AF systems struggle – in low light or heavily backlit situations, for example. 5 Customise the camera In my view, one of the best developments in autofocus in recent years is the ability to customise the camera so that it responds to specific focusing situations. I like my autofocus to ignore subjects that briefly pass in front of the camera, for instance. When I’m working in a busy pit lane and someone walks in front of the lens I usually want the autofocus to stay on my intended subject, rather than locking on to this distraction. I find Case 3 on my Canon camera (which focuses instantly on subjects that move into the AF points) works really well in this type of situation. 6 Anticipate the action If you need to capture a subject that is either moving too fast for the AF to follow, or the lighting conditions are beyond the capabilities of your autofocus, then you can use a technique known as pre-focusing. Simply focus on an area ahead of your subject. Now wait for your subject to pass through this area, and either try to take the shot once the subject appears in focus (if it’s slow moving and you’re quick on the shutter) or fire a burst of images and select the one that lands perfectly in focus. This is particularly effective with high frame rate sports cameras.
7 Use cross type points Not all AF points were created equally. On many cameras the central autofocus points will perform better than the peripheral ones. This is due to the centre AF points being a cross type, these points use two opposing line directions on the autofocus sensor to give greater accuracy when focusing. Many of the outer AF points (sometimes called assist points) only use a single line/dimension on the sensor. You may also find that when you’re using teleconverters you can only use the central cross type AF points and that the performance is improved.
8 Look for contrast Many autofocus systems will lock on quicker or more accurately in areas with definition or contrast. When shooting cars or bikes look for these areas of contrast such as number plates, race numbers or even headlights. This can be particularly effective when shooting in fading light conditions.
9 Reassign focus Most professional motorsport photographers will have their cameras set to a custom feature known as ‘back button focus’. This is where you remove the autofocus start/stop function from the shutter release button and reassign it to the AF- ON or * button.
Doing this allows you to ‘set’ the focus and then release the shutter in two separate actions. It’s generally used in conjunction with continuous autofocus.
For example, if you have your central autofocus point selected, you can focus your shot and then recompose putting the stationary subject elsewhere in the frame without changing any of the settings. The only other way of doing this is to use manual focus, change to single shot AF or move your autofocus point. But all of these actions require you to change settings or take the camera away from your eye.
An additional advantage of this system to motorsport photographers is that at any point you can change subjects and you have a continuous focus set-up ready to catch any unexpected action.
It can also be useful when panning through objects in the foreground (crowds/trees etc). I often set the focus through a gap in the crowds, leave it set, and only use the shutter release.
10 Test your lenses Not all lenses come perfectly calibrated. If you’re shooting fairly narrow apertures like f/8 then you’re unlikely to notice if a lens is a few mm front or back focused. However if you are using wide aperture lenses for their shallow depth of field you will soon notice if you’re always getting drivers’ noses in focus instead of their eyes.
The way to test and adjust this is to use an open book at 45° to the camera. Take a shot at your widest aperture using a central single spot AF point. See how many lines of text front or back from your target the actual focus point is in the photo, and then adjust your AF micro adjust settings for either the lens or the body (adjust the body if the focus issue is the same on all lenses you test).