Moving subjects – like birds in flight or dogs chasing after a ball – are more difficult to keep in focus than static ones using the standard (auto) autofocus mode. While auto AF mode can alternate between single and continuous autofocus when it identifies a moving subject, selecting continuous AF mode (AF-C) will give more consistent results.
AF-C enables you to keep the focus bang on track, focusing on your subject continuously all the while the shutter-release button is half-depressed.
Here’s how to get set with AF-C:
- Choose AF-C by holding down the AF-mode button on the front left of the camera and simultaneously rotating the main command dial until you see ‘AF-C’ in the viewfinder or on the control panel.
- Choose the focus point position: flick the focus selector lock on the back panel down from ‘L’ to the small dot. Use the multi-selector arrows to choose the focus point you want, and press OK, then flick the selector lock back up to ‘L’ to stop the focus point changing next time the multi-selector is pressed (for example, during image playback).
- Now quickly compose your shot and half-depress the shutter. As long as the button stays half-depressed, your DSLR will continuously track the focus to keep the moving subject sharply in its sights.
In AF-C mode, if the subject moves towards or away from the camera, the predictive-focus tracking is automatically triggered. This calculates what is most likely to be the subject’s position (based on its speed and direction of travel) at the moment of capture and adjusts the focus accordingly – making up for the short time lag that occurs between releasing the shutter and capturing the image.
With particularly fast or erratically moving subjects, you might find it tricky to keep the focus engaged and shoot at the same time, so to get round this you can use back-button focusing instead of the shutter release. On top-end Nikons there’s a specific button on the back plate which can activate the focus; on all other models you can assign this function to the AE-L/AF/L button.
Subject tracking on COOLPIX cameras
Your COOLPIX maintains its focus on a moving subject using a contrast-detection system called Subject Tracking, which is based on the principle that in-focus objects display the highest contrast in a scene.
The system analyses the image information of the subject obtained by the image sensor. Then, by moving the lens, it seeks the lens position where the image contrast is highest. Subject Tracking is particularly useful when capturing children or pets at play and ensures sharp focus and quick response to capture your best shot.
The best thing is that this happens automatically, so all you have to do is press the shutter and your COOLPIX will do the rest.
Original article here