Your dSLR camera shutter speed determines how long light reaches the image sensor to record an image. The shutter speed is typically measured in fractions of a second (e.g., 1/60, 1/125, 1/500 second) That’s lightning fast! But that’s all the camera needs to record an image.

We can reason that the higher the shutter speed, the faster the camera captures a slice of life. This is how a camera stops motion, whether it’s LeBron James dunking the basketball, a hummingbird in flight or water being thrown from a bucket. Conversely, a slower shutter speed reduces the camera’s ability to stop action because the subject is moving from one place to the next faster than the shutter can open and close.

Your camera has shutter speeds ranging from 1/800 to 2, 4 or 8 seconds. There may also be a bulb option which is a setting that allows you to hold the shutter open as long as you want by holding the shutter release button down. So the possibilities are extensive.

As the shutter speed effectively allows you to control how you capture motion, you have to be mindful of the fact that you can also capture the kinetic energy of motion by incorporating motion blur into your pictures. Although that’s a highly stylized artistic choice, it’s best to know when you start to see motion blur so you can control where and when it’ll show up.

You start to see motion blur in your images at shutter speeds of 1/30 and below. It’s really apparent at 1/8, but shooting at 1/8 requires a tripod or monopod to hold the camera steady. At these slower shutter speeds, the vibrations from your own breathing make it difficult to hold the camera steady enough for an effective picture. Where slower shutter speeds really come in handy is when you want to increase your depth of field by increasing your aperture setting (f-stop number), such that to maintain proper exposure, you must increase the time that the shutter remains open.

The shutter setting allows you to alter your exposure value. The lower the speed, the greater your exposure value (and the opposite is true). So you’ll have to adjust your aperture setting and/or the ISO rating to maintain an effective exposure.

Controlling the shutter allows you to acquire images with varying qualities. For example, your girlfriend is running outside in the rain. With a high or fast shutter speed, you’ll not only stop her but the raindrops as well. However, if your girlfriend loves to experience fresh rain cascading down her face, you can reduce your shutter speed and as she smiles up at the sky you can snap off a picture in which she’s properly exposed and sharp, but the raindrops are a blur. The effect might not be immediately apparent to a viewer, but those two images will convey a different sense of time, space and emotion.

The shutter speed lets you capture those moments that are once-in-a-life time moments. These moments can disappear faster than you can snap your fingers. You could miss that moment if the shutter speed is too slow or too fast.

It’s also important to note the shutter lag when selecting a digital camera. Shutter lag is how fast the shutter resets after you release it. The shutter lag is the delay that occurs after you press the shutter button and how long it takes for the camera to cycle back so you can take another picture. With compact/point-n-shoot cameras, the shutter lag is somewhat long, even in burst-shooting mode. With a dSLR the shutter lag is somewhere between 0.2 and 0.5 seconds. That’s why you can capture the decisive moment so perfectly with a dSLR.