Correct exposure is important for objective imaging, but can be difficult to achieve. Over-exposure will result in the brightest pixels in the image being “clipped” or “saturated”. As pixels become brighter they reach this level and cannot go any higher,


ISO refers to the level of sensor gain, taking the name from “film speeds” back when we photographed on analogue film. Higher ISOs make the camera sensor more “sensitive”, allowing for photography in lower light levels. However, increasing the ISO

Focus and Aperture

A wider aperture lets more light onto the sensor, so is useful in lower light conditions, however wide apertures also reduce the depth-of-field (so out-of-focus parts of a scene are more blurred) and will tend to exacerbate lens design imperfections