Auto-focusing feature for mobile phone cameras

Camera-enabled mobile phones typically rely on fixed focus lenses to take anything from close-ups of people’s faces to landscapes. Since these are new devices and users’ expectations have been held back by low resolutions and applications limited mainly to sharing images on the phones’ low-resolution displays, image quality has not been a major selling point. As the phones become more popular and higher-resolution models are made available, comparisons with entry-level digital cameras will be drawn, and image sharpness and performance at a range of different illumination levels will become critical factors in a user’s buying decision. Apart from user demands, the problems will get worse as sensor resolutions increase because the size of individual pixels will invariably shrink to retain a small form factor and this reduces both the amount of light captured by the pixels and the depth of field available to camera phone users with fixed-focus devices.