Glossary of Terms

Photography is full of terms. Here you can find their definitions.

Aperture – Put simply, it’s the hole that light passes through. It can be opened and closed to allow more or less light to reach the recording medium. The size of the hole in relation to the lens length is referred to as an F-stop. Common F-stops are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22. To find the F-stop number, divide the focal length by the aperture diameter.

Depth of Field (DoF) – The amount of an image that is in focus as it relates to the distance from the camera. A “shallow” depth of field means that very little is in focus, front to back, in the image. A “deep” depth of field means that most or all of the image is in focus, front to back. Aperture and focal length are the influencing factors. (Aperture influenced DoF, Focal Length influenced DoF)

Exposure Triangle – The relationship ship between Aperture, Shutter Speed, and ISO to attain the optimal exposure.

ISO – In basic terms, it’s the recording medium’s sensitivity. In film and analog media, ISO may also be referred to as ASA or DIN and is related to its sensitivity to light. With digital sensors, there is a base (or native) ISO and anything above or below that ISO is done by amplifying or reducing the signal of the sensor.

Moony-11 – Shutter speed is 1/ISO, aperture varies depending on phases of the moon (see table). Useful for getting approximately the correct exposure when photographing just the moon.

Shutter Speed – How fast or slow, measured in seconds or fractions of a second, that the shutter stays open.

Sunny-16 Rule – Shutter Speed is 1/ISO, aperture varies depending on weather conditions (see chart). Useful for quickly getting the correct exposure outdoors during the day.

Stop – A term used to denote half or double the amount of light falling on the recording medium. Moving from f/2.8 to f/2 would be one full stop and double the light falling on the sensor (all else being equal). Likewise, moving from 1/60 sec. to 1/30 sec in shutter speed would be one full stop more light. Moving from ISO 400 to ISO 200 would be one full stop but would halve the sensitivity of the recording medium.