How to use depth of field shots?

Watch TV shows and films often have such a scene: two guys off the lens a far a close, a virtual one. From closer to the screen before talking, said after the way he suddenly become blurred, and who later became clear, and then the dialogue. In fact, this is the depth of field. Depth of field can be understood as the number of objects, light can correct convergence on the CCD, big see TV shows and films often have such a scene: two guys off the lens a far a close, a virtual one. From closer to the screen before talking, said after the way he suddenly become blurred, and who later became clear, and then the dialogue. In fact, this is the depth of field. Depth of field can be understood as the number of objects, light can correct convergence on the CCD, large depth of field is more objects can be clearly displayed on the screen, the small depth of field and vice versa. Every photo has one or more of the subject, removing all unnecessary factors highlight the basic principal is photography. Such as when shooting portraits, if you can find a solid color background, of course, the best, but very often we do not have such a condition, then you can use depth of field. Through the small depth of field, the background virtual can highlight the principal. But in taking scenery photo, in turn, requires a large depth of field will include as much information as possible. On the "stupid machine", it is difficult to control depth of field, by selecting different modes, such as people like mode, or use the macro function, in particular the Ricoh R1, RX, and so you can make 1CM macro good depth of field effect. But with manual functions GX, no problem, especially with 2.5 aperture f2.8 than General. Coupled with the aperture priority mode (A), bear this "large aperture small depth of field, small aperture large depth of field" principle, take a single object to the aperture as large as possible (in normal exposure limit), and would like to accommodate more something down the aperture.