The f-stop, otherwise known as the aperture, determines your depth of field (the area in focus) and how much light can pass through the lens to reach the sensor.

Shooting with a wide Angle lens gives the image a sense of depth, but keeping the vertical lines straight allows it to be appear very Stoic.

This paper introduces entire focus imaging technology, including the focus and depth theory, fast entire focus lens, fast imaging technique and signal conditioning circuit.