I was browsing through some old messages on the forum and I found a post
by Arks requesting technical details to be posted with pictures. I've recently posted a number of pictures of flying bird and I thought it might be interesting to post the details of how I take these shots:
When photographing flying birds, or any moving animal, it's extremely difficult to keep a sharp focus. My camera has a nifty feature called AI Servo
focusing. Most modern prosumer SLR cameras will offer this mode. When you select this mode on the camera it will constantly try to focus on the subject covered by the focus points. This means that all you have to do is keep the subject in the viewfinder, the camera will make sure the subject is in focus (this is all theory though, in the real world it requires some practice
High-speed continuous shooting
In combination with AI Servo mode I always select High-speed continuous shooting mode. When I set my camera to this mode it will take pictures as long as I press the release button on the camera. This means that it will take 5 pictures per second. When using high-speed mode some pictures will be out of focus because AI Servo didn't track correctly, some will be out of focus because of you shaking the camera while taking pictures and some pictures will be okay. After some practice I now get around 80% sharp pictures in high-speed mode.
Most prosumer SLRs will offer a high-speed mode, consumer SLRs probably don't have this mode.
To get pictures where the bird seems to frozen in flight you'll need shutter speeds of 1/750 sec or faster. I usually try to get shutter speeds of 1/1250 sec or faster. To get shutter speeds this fast you either need a lot of light or fast film (high ISO number). If you use a digital camera then you probably have the option of setting the ISO number on the camera. In that case select a high ISO number to obtain fast shutter speeds.
When you take a picture your camera will calculate the exposure. Your camera assumes that the scene you are taking a picture of on average reflects 18% gray. In most cases this is true, but there are situations where you have to manually correct the exposure. When a scene reflects more light than 18% gray then you have to overexpose (add exposure stops) and when a scene reflects less light then you have to underexpose. I can try to explain all this but other people have already done that, see for instance http://www.photozone.de/4Technique/ec.htm
Direction of sunlight
You get the best pictures when the sun shines on the subject (see example 1). When the sun is behind the subject (backlit) or from the side you lose detail in the subject (see example 2). Early morning or late afternoon sun gives the most pleasing results.
Using a digital camera is very handy when taking pics of flying birds. You can check the exposure on the LCD and you can throw away any shots you don't like. I used to use Velvia slide film before I switched to a DSLR and taking pics of flying birds used to be an expensive hobby...my EOS3 took 10 shots a second (3.5 seconds per roll
Shutter speed: 1/1250 sec
Exposure compensation: +1.0 stops
Focal length: 420mm
I added 1 stop exposure (so I overexposed 1 stop) because I wanted to see some detail in the black breast of this bateleur. If I hadn't done this then the detail would have been lost and the picture would have been less appealing.
Shutter speed: 1/4000 sec
Exposure compensation: none
Focal length: 420mm
I should have added at least 1 stop to the exposure in this shot. Now the black breast doesn't show any detail and the shot is a throw-away.
Shutter speed: 1/2500 sec
Exposure compensation: +1.0 stop
Focal length: 420mm
I added 1 stop exposure because the sky was overcast. This meant that the background was an unappealing white, but worse than that it confuses your camera. A camera assumes that when you take a picture the overall average colour is 18% gray. When you shoot a shot like this that assumption is wrong, the background is much lighter than 18% gray. If you don't overexpose this shot then it will be much darker. I've simulated the exposure which the camera had calculated below: