Camera Basics

Camera Modes

Most digital SLRs have four main modes which include,  aperture priority (A or Av), shutter priority (S or Tv), program mode (P) and manual mode (M). There can be others as well but they tend to be automatic or scene selection modes where the camera makes all the decisions for you. For the purpose of […]


In digital imaging a pixel is the smallest amount of data in any one image. The number of colours that can be shown by any one pixel is determined by the bit depth of the pixel. Most digital images today are either 8bits/channel or 16bits/channel. The list below shows how many colours are in 1 […]

Shutter Speed

Shutter Control The cameras speed setting on modern DSLRs is set using control dials on the camera something similar to those shown in fig 1. In order for the user to select the speed the camera must be set either to manual control or shutter priority. In manual the user has full control over both […]

Focal Length

  Focal Length When parallel rays of light hit a lens, the distance from the centre of the lens to where the rays meet (focal point) is called the focal length.     On older lenses the focal length shown was quite literally the length of the lens, however modern lenses use multiple lens setups […]


The aperture is the opening of the lens that light travels through to the film or sensor. Most lenses have a diaphragm which can be opened and closed to allow more or less light into the camera. The aperture and shutter speed effect the exposure of the image and have a direct relationship with each […]