Exposure triangle
Shutter speed
The shutter speed is the amount of time the camera’s shutter remains open when taking a photo, it controls the amount of time that we capture light for and allows us to freeze or blur motion. When we take a picture, the camera’s shutter opens to allow light to reach the recording medium, thereby allowing an image to be created. By controlling how long the shutter stays open, we can control what the resulting image looks like. Also known as exposure time, shutter speed is measured in fractions of a second (seconds or tenths or hundredths of a second). For example, a slow shutter speed of 1/2 means the shutter remains open for half a second, while a faster speed of 1/2000 means it only remains open for one-two-thousandth of a second.
Aperture
Aperture refers to the size of the opening that light passes through before hitting your camera’s sensor. By controlling the aperture, we can control how much light is recorded in an image as well as the depth of field. The larger the aperture, the more light is recorded and the shallower the depth of field. With smaller apertures, less light is recorded and the depth of field is greater. Aperture is recorded in f-stops and is shown by the symbol 'f'.
ISO
In photography ISO measures how sensitive the recording medium is to light.
Higher ISO numbers are more sensitive to light, whereas lower numbers will be less sensitive to light. While increased sensitivity may sound good in theory, the main drawback is that higher camera ISOs result in a degradation of image quality, which often appears in the form of ‘noise’, especially in the shadow tones.
To correctly expose an image, I need to find a balance between both shutter speed and aperture, which I can do by using your camera in Manual mode while referring to the built in light meter.
Most cameras, mine too have a meter from -3 to +3 stops, with 0 indicating the ‘correct’ exposure (this is according to your camera). Anything to the left of 0 (in the minus) is considered to be under-exposed and anything to the right (in the plus) is considered to be overexposed.
