Every day, in some way or the other, we create memories that we want to cherish for our entire life and the best way to do that is to capture them. Starting with Android 4.0 (API Level 14), your camera application can provide additional controls to allow your app or users to specify areas in an image to use for determining focus or light level settings and pass these values to the camera hardware for use in capturing images or video.
Cameras should be mounted as close possible to the field of view required, and the closer the camera to the subject the better the identification of the subject will be. Proper lens selection relative to the camera location and the FoV required is essential to a quality picture.
The Canon Ixus/Powershot digital camera I use routinely is rated at 7.1 megapixels, which is perfectly fine for almost anything I ever want to do. My new LG smartphone comes in at 13 megapixels, which (theoretically, at least) sounds like it must be twice as good.
Note: With the introduction of the Multi-Window feature in Android 7.0 (API level 24) and higher, you can no longer assume the aspect ratio of the preview is the same as your activity even after calling setDisplayOrientation() Depending on the window size and aspect ratio, you may may have to fit a wide camera preview into a portrait-orientated layout, or vice versa, using a letterbox layout.
In one game-changing leap the revolutionary image sensor and high-speed processing of the Sony Alpha a9 Mirrorless Digital Camera Body reaches performance levels far beyond the incremental improvements gained through decades of mechanical refinement.