Take a photo Control the camera ANDROID TIPS
When you start to take a shot, the camera lens will begin to autofocus on the object to ensure that the camera software can get the best exposure/white balance for you.
However, there are few ways you can take back control of the shot process. For example, if you tap the view screen, you can then change the primary focus and set it to say a background object instead of a foreground. Also, while there is no dedicated option in the menu, you can get in pretty close to objects to take macro-style shots. Additionally, you can tap on the small circle (with the A inside) to switch the camera view to the front lens for self-portraits, or pinch the screen to zoom in/out to take pictures at a greater distance, but bear in mind that the results will vary dramatically.
Source: Android Tips, Tricks, Apps & Hacks Volume 8 © 2014 Imagine Publishing Ltd