Amazing things are happening to the next generation of cameras for Smartphones, and soon mobile phones will be able to take pictures which are as good as those produced by expensive Digital Single Lens Reflex cameras (DSLRs). The cameras on modern mobile phones are highly sophisticated with multi-mega pixels and many programmable functions. In fact quite astounding photographs and even movies can be recorded with no more than a phone.
There is one area though where phone cameras have failed to compete with DSLRs or even bridge cameras, and that is in the control of depth of field. Depth of field (DoF) in a photograph refers to the region within the scene that is in focus. For instance, in a portrait taken by a DSLR, the photographer can use a very wide lens aperture to narrow down the DoF so that only part of the image is in focus. This can produce some excellent effects, for instance by ensuring that just the model's face or even just the eyes are in focus and everything else is blurred, concentrates the viewer's attention on the main features and removes any distractions to produce an artful photograph. This is only made possible by the large aperture lenses used by DSLRs.
On the other hand a phone camera has a relatively small lens, so it is not possible to use a large aperture, and portraits taken by phones are relatively poor as all areas are in focus simultaneously. Now a new generation of phone cameras is being developed that will overcome this shortcoming. This does not use a large lens, obviously that would be impractical on a phone, but instead uses a clever computer controlled mechanism that controls the position of the lens. When the user takes a portrait shot, the camera will record the scene entirely in focus, then the lens will be moved back and forward recording frames all the time so that the background and foreground are all rendered out of focus, or blurred.
The camera will combine these multiple frames into a single shot with the important features in focus and the other regions blurred. These developments are still in the laboratory, and so are unlikely to appear on the next Nokia model, but it shouldn't be long before you can take professional looking pictures just using your mobile phone.