Aperture and Focal Length

Aperture determines how much light can be captured by the lens. It’s notated by f/x.x (e.g. f/2.5). The lower the floating number, the higher sensitivity to the light and it can capture more light.

Focal length determines how much (or wide) can be captured by the camera. It’s written in millimeters (like 25mm, 35mm, 120mm). The smaller the mm, the wider it can capture. The bigger the mm, the better its ability to capture picture in zoom.