How Does Shutter Speed Effect an Image’s Exposure?

One of the three main settings you can adjust on your digital camera is the shutter speed.  Altering this setting will have a direct effect on an image’s exposure – how bright or dark the color is.

So how does the shutter speed effect an image’s exposure?

Letting Light In Over Time

Your digital camera takes a picture by exposing its internal sensor to light. The light comes into the camera, contacts the sensor, and is converted into an image with (hopefully) vibrant colors and crisp details.

This sensor is normally shielded by a pair of doors – the shutter – which keep the light out. When you press the button to take a picture, the shutter opens up, allows a little bit of light in, and then quickly shuts itself.

The shutter speed setting on your camera is a measurement of how long the shutter stays open. Typically, this isn’t very long.  A quick shutter speed (like you would use for sports) would be something like 1/500th of a second – a tiny fraction of a second.  A slower shutter speed (like you might use indoors with a flash) would be something like 1/30th of a second – a less tiny fraction of a second. You can leave the shutter open longer – and some types of low light photography involve opening the shutter for many seconds at a time – but this is uncommon.

The longer the shutter is open, the more light is allowed to come in. So, if you pick a slow shutter speed (like 1/30th of a second), you will let in more light than a quick shutter speed (like 1/500th of a second).

How Else Does Shutter Speed Effect an Image?

As with other camera settings, there is a trade off. So read the next post to find out how else the shutter speed will impact your image.