In this article, I explain how I went about capturing images of birds fighting in a Hungarian marsh back in January. In particular, how I tailored and used autofocus parameters specifically for this type of shot.
I specifically set out to get images of fighting water birds. From previous visits to Kiskunsagi in winter, I'd seen that the birds frequently battled over the well-stocked marsh lake. These arguments erupt and end suddenly, and with 30 or more birds in the immediate vicinity of the hide it can be a little daunting to try and work out which might fight (and so which to follow in the viewfinder... and when).
For me, the best preparation for this sort of shot is to photograph in the same place for several days. On this occasion, I found it helped to avoid photographing fighting at first, taking time to just watch what was happening instead (you can miss a lot if you spend all your time glued to the camera eyepiece!). After doing this for a while (taking a few portrait shots in the meantime - it's hard to resist photographing when there are subjects just in front of you), I started to get a feel for how the birds behaved just prior to a fight breaking out, and the likely spots for fighting (some parts of the water attracted a higher density of birds which resulted in more fighting as they clambered for position. I started photographing the action towards the end of the second day and continued for 5 days in total.
When taking this sort of shot, the main technical challenges are :
- focussing quickly on the subjects and keeping them sharp throughout a sequence of shots
- keeping the birds within the frame as they fight - they tend to suddenly move in unpredictable directions
- avoiding getting the myriad other bystander birds in the area in the shot or, worse, in front or behind the fighters
Here's the way I tackled the problems... (I'm afraid some of this - the camera autofocus settings - is Canon-centric, but the rest is applicable to other cameras)
Choosing the right lens:
To maximise the autofocus effectiveness I used a wide aperture f/2.8 zoom for these shots, rather than the usual super-telephotos that I employ. The fast f/2.8 aperture allowed me to keep the shutter speed high and the ISO within acceptable levels. It also meant that autofocus worked at maximum speed (as maximum aperture gets smaller, autofocus tends to slow and on many cameras some AF points cannot be used at all). Speed of focus can be further improved by setting the focus range limiter on the side of the lens - in this case, I chose the 2.5m-infinity setting. I also chose a shorter focal length than I normally use - a 70-200mm zoom, mainly used at 150mm plus. This focal length gave a bit of space around the birds while still keeping them the dominating element in the picture, making it easier to keep them in frame (challenge (2) above) than if I'd gone for a more tightly cropping 300 or 400mm. Shooting at a wide aperture means that the background can be blurred out to some extent, which reduces distraction in the image. Unfortunately, it also means that only a relatively small part of the image will be in focus so you're reliant on the birds staying level with one another in the same focal plane during the shooting. Strangely, they don't always do this (no matter how many times you tell them) so a fair bit of perseverance is required to get a sharp shot.
Leveraging fast AF systems
I used a camera with especially good autofocus speed and precision - a Canon 1DX (the same focus system can be found on the 5DS, 5DR and 7D Mark II and you can bet that versions of it will find their way into more and more future models).These cameras differ from Canon's other DSLRs in that they also use colour information to help tracking and have separate Autofocus chips rather than sharing processing power with other camera functions). In AI-servo mode (AF-C in Nikon speak) their tracking abilities are significantly better than other Canon models making it possible to use all the focus points of the camera when taking action shots - you just select the initial point that you want to start tracking from and make sure that you get that focus point onto the birds' head. Well, you didn't think that the camera would do it all did you? As the photographer, it's up to you to initially get an accurate aim on the target, after that the camera can help you keep the focus locked on and track it as it moves). For a lot of experienced wildlife photographers (myself included), the idea of having all 61 focus points active (or more, in the case of the 7D2) is a major change in approach. Previously, AF tracking was just not good enough for these sorts of photo so the photographer generally turned it off (or significantly limited it) by choosing just a single active point, or, occasionally a small group of neighbouring points and manually keeping this on the subject. It was a genuine shock to my photographic system when I first experienced the 1DX AF tracking capabilities a few years ago.
The camera allows you to customise the way the autofocus tracking reacts to direction change and speed change of the subject; as well as how it behaves when it encounters an object briefly in the way of the subject. Canon have set-up six pre-set 'cases' that the user can switch between (and even customize), and choosing the right one makes a real difference in focus tracking. (Note - you'll also need to make sure that iTR is turned on (it's activated in one of the autofocus menu screens) - for reasons I don't really understand, the cameras ship with it turned off by default...) Fighting birds tend to move erratically and accelerate / decelerate quickly. This most closely matches Canon's case 6 "focus on subjects with erratic movement and changes in speed', so this is the one to select. In fact, I've customised my case 6 to the values (0,2,2) from it's default (0,1,1) as I've found that, for me, this works best for fighting. To some extent, the detailed adjustments are user specific - different people move the camera differently, some smoothly, some less so. The settings are not just about the subject, they are about the way the camera is moved! If you have a tendency to jiggle the focus points up and down while tracking, then more aggressive AF settings will work best. If you're a super-smooth operator who can keep a focus point on a birds head with graceful, fluid wrist movements while it fights for its life then you might want to turn down AF auto switching and Accel/decel tracking parameters a bit! To be honest, pretty much everybody is fairly jerky when trying to follow fighting birds leaping almost randomly around - dialling things down a bit is more relevant for e.g. flight shots, which are a bit less erratic.
Canon USA has a downloadable PDF guide to the 1DX AF system (there's also a version for the 7D Mark 2 on their site) which covers things in a fair amount of detail, for those interested.
So, all this is well and good... but what if you don't have one of the above cameras? Generally, selecting a small group of points (1+8 helpers or a block of 4 or 9) worked best for me with another model - the 5D Mark IIl - although the hit rate of pin-sharp images was significantly lower than with the 1DX. A co-conspirator of mine who uses a Nikon D4S reckons that a single point is the way to gofor these shots (I've tried the 3D focus option on the D4 and D4S, which are Nikon's equivalent of the above Canon set-up, but I personally couldn't get this to track birds effectively. That could just be my relative unfamiliarity with Nikon). On other Canon models, single point, or single point with four helpers (if you have this mode) is generally the most useful.
Taking the shot
When I found a pair of birds that I thought might be about to fight, I locked the initial focus point onto them, then released the AF and waited. When they started to fight I activated the AF again and, when (or should that be 'if', as it's not that easy...) I got a lock, shot, following the birds and keeping them in the centre of the frame as best I could. I used a rigid tripod with a Uniqball head set totilt/pan only. A Gimbal head, or maybe a two-way fluid video head with adjustable damping, would also be good options.
In between shots, I refrained from looking through the view finder so that I could scan the entire scene with my eyes and keep checking for isolated pairs of birds that looked as if they were candidates for action. This is really the only way I could think of to overcome problem (3) although much of this relies on luck as to where other birds may be standing.
Even with a fast lens and state-of-the-art Autofocus, it's not easy to get sharp pictures of fighting birds. It takes practice, and a bit of patience... and luck (especially in terms of how the birds position themselves during the action and whether they are both in the same focal plane). It's a great challenge though, and you feel good when it works out!