When taking pictures with a normal camera, it is not easy to use. There is a "fool" camera,
You said the fool machine, due to the use of a small wide-angle lens (short focal length) and a small aperture, so it has a large depth of field range, generally can do 1.5 meters ~ infinitely clear range.
Early camera because there is no auto focus function, focus need to manually, but encountered unexpected events is too late to tune, so the use of the camera's so-called "super focal length" to shoot, then the camera and the lens will generally have depth of field Table tips.
Lens depth of field features: the shorter the focal length of the lens, the depth of the field is relatively large, the smaller the aperture the greater the depth of field, on the contrary the opposite.
Here to talk about why he does not need to focus on the problem can be clear, answer this question before you first talk about the "depth of field" concept. The depth of field is when the lens is focused on an object after focusing, the object in the focal plane (film or digital CCD) to form a clear image, but the focus of the front or rear of a range of objects can also be a clear image , We put this section can be clearly imaged area called depth of field.
The real fool camera is fully automatic, including auto focus (AF), you said this fool machine is actually the last century film era is more common a simple camera, this camera is characterized by a shorter focal length, focal length Not adjustable (or have a simple graphical indication), effective aperture (aperture) smaller, more use of simple program shutter.
