1. Shutter, aperture and ISO
Most modern cameras do a good job on their own with automatic settings, but sometimes the result isn’t what you imagined. Then it might be good to know what shutter, aperture and ISO means. This lesson is a bit more advanced than the upcoming ones and you don’t need to understand everything. However, if you really want to learn how to work with your camera, this is important basic knowledge.
The shutter works the same way as a curtain that opens when you click the shutter button. Shutter speed is the time that that “curtain” is open and lets light into the camera. If you photograph objects in movement you need a fast shutter speed to avoid motion blur. If you photograph in good light, the shutter speed is normally not a problem, but in bad light your pictures might get too blurry as the shutter needs to be open more time for a sufficient amount of light to enter.
The shutter speed is the number on your display that looks something like this: 1/100, 1/500, 1/1000 (sometimes written without the “1/”). The higher the number behind the slash, the shorter time the shutter is open.
The aperture works a bit like the pupil in our eyes – its size regulates the amount of light entering the camera. The aperture also controls the so called depth of field, deciding how blurry the background gets compared to the subject in focus. Many photographers work with shallow depth of field to separate the subject from its background.
The aperture is the number on your display that looks something like this: 2.8, 4.5, 5.6, 11 (sometimes written with “f/” in front of the number). The lower the number, the bigger the aperture (more light enters) and the shallower the depth of field (blurry background).
Low ISO gives good image quality (click the photos to see them bigger and to facilitate comparison).
The ISO controls light sensitivity. Generally you want to keep the ISO as low as possible, since high numbers give grainy photos. If the light is bad you might need to put the ISO up to compensate.
The ISO is the number on your display that looks something like this: 100, 200, 400, 800, 1000. Low numbers mean less light sensitivity but also less noise.
How it all fits together
Now you have learned about the three single most important factors controlling the result. It’s all about getting the right amount of light into your camera so that your photos don’t end up either over- or underexposed (too light or too dark). What setting you should use depends on what you’re photographing, but also how much light you have to work with and what gear you’re using. If you want a blurry background you should use a big aperture and if your subject is moving a fast shutter speed is necessary, but remember keeping the ISO as low as you possibly can. The best thing you can do is to experiment with different settings until you get a result that you’re happy with. Good luck!