If you own a digital SLR camera you may have noticed there is an option for taking “one shot” photos as well as AI servo, which are basically two different methods of focusing. The standard or default setting is one shot and is typically the most used method.
In this method, if you hold the shutter button halfway down it will focus the camera on the subject it will then keep the image in focus until you take the photo. This is most commonly used when you’re taking shots of something that isn’t moving or is still life.
On most cameras you’ll have to use the one shot setting when using a flash as the focusing grid won’t work in the AI servo mode. However, the AI servo mode is ideal for many other photography situations.
This is the mode you want to use when you’re trying to keep a moving subject in focus, meaning it’s especially good for sports photography. When the subject moves further away or closer, he or she should stay in focus and the digital camera will continue to update its focusing capabilities and keep the person or thing as sharp as it possibly can.
Basically, the type of shot you’re trying to get will dictate which focusing method you should be using. Obviously, if it’s a moving object or person the odds are you’ll be going with AI servo and if it’s still life you’re after then the one shot will probably be used. Of course, you can also use AI servo for still life photos too if you like.
Everybody has their personal preferences when it comes to focusing and other types of camera modes. If you’ve never experimented with the one shot and AI servo modes it’s not a bad idea to give them a try and see which one provides you with the best results
. As mentioned before, if you’re shooting sports or any type of moving object the AI servo option should serve you very well. The more you use the options the more you’ll be able to judge which one is the best to use in specific photography situations.
To recap the modes, when you’re in auto focus the one shot option locks the focus in when you press half way down on the shutter release. If you have something called AI focus on your camera this is basically a smart mode.
It works just like one shot, but if your subject starts to move the setting will automatically change over to AI servo. And when you’re in the AI servo mode, the camera’s focusing system is working all of the time and will track moving items and keep them in focus.