We’ll start with a good one. Shutter speed isn’t particularly difficult; it is just the amount of time your camera spends taking a picture. This could be 1/100 of a second, or 1/10 of a second, or three seconds, or five minutes. Some people build custom cameras that take decades to capture a single photo.
Your camera won’t let you take a decades-long photo. Instead, the longest allowable shutter speed tends to be around 30 seconds, although it does depend upon your camera. For example, on the Nikon D850, you can shoot any shutter speed from 1/8000 second to 30 seconds, as well as a time mode for even longer exposures. Other cameras generally allow similar settings.
So, why does shutter speed really matter? There are two main reasons:
First, as you would expect, a long shutter speed (several seconds) lets in a large amount of light. If you take a normal daytime photo with a 30-second shutter speed, you will capture an image that is completely white. The opposite is true, too; a quick shutter speed only lets in a small amount of light. If you take a photo at night with a 1/8000-second shutter speed, the photo will be completely black.
Take a look at the series of examples below. Here, 1/25 second was too dark (“underexposed”), and 1/3 second was too bright (“overexposed”). This should give you an idea of the brightness differences with shutter speed:
Second, the only other big effect is the motion blur in your images. Not surprisingly, a long shutter speed (such as five seconds) captures anything that moves during the exposure. If a person walks by, they might appear as a featureless streak across the image, since they aren’t in one place long enough for the long exposure to capture them sharply. That’s called motion blur.
By comparison, a quick shutter speed (such as 1/1000 second) does a much better job freezing motion in your photo — even something moving quickly. You can photograph a waterfall at 1/1000 second and see individual droplets frozen in midair. Without a camera, they might have been invisible.
Take a look at the images below. Here, I was taking pictures on a windy day. The foreground grass and the waves behind them were all moving quickly. As you can see, depending upon my shutter speed, there was a major difference in motion blur:
There are two types of motion blur that you may encounter due to your shutter speed: camera blur and subject blur.
If you’re doing handheld photography, camera blur could be very significant. It’s impossible to hold your camera perfectly still while you’re taking a picture, and even slight shake can lead to very blurry photos. That’s one reason why many photographers end up using tripods!
However, although a tripod protects against camera movement, it does nothing to prevent scene movement. For example, if you’re taking landscape photos on a windy day – even with a tripod – you might end up with areas of blurriness, as in the image above. This is called subject blur.
Sometimes, you can use camera or subject blur artistically, and it looks good. For example, if you’re photographing water in the bay or at the beach, a long shutter speed might be a nice touch:
However, in many cases, you probably will want to eliminate motion blur so that your entire photo is sharp. If that’s your goal, you need to pick a shutter speed that is quick enough to freeze any movement. So, what shutter speed should you use? Is there a good range that tends to provide sharp photos of moving subject?
Not really, because it all depends upon some outside factors – most importantly, the amount of movement in your scene. If your subject is moving very quickly, you’ll need a fast shutter speed. If your subject is standing still, or only moving very slowly, you can get away with a longer shutter speed.
Also, the farther you zoom in (i.e., the longer your “focal length”), the more you’ll magnify motion blur. So, you’ll find that you generally need quicker shutter speeds to freeze motion properly when you’re using something like a telephoto lens.
The best route to learn all of this is just to keep practicing. Over time, you’ll build a good mental picture of the shutter speeds you can use in a particular environment without risking motion blur. Whether that’s 1/250 second, 1/10 second, or 20 seconds, it’ll be second nature. Also, after you’ve taken a picture in the field, review it and see if there is any blur when you zoom in. If so, you’ll need a quicker shutter speed.
Want a quick-and-dirty guideline? Use 1/500 second or faster for sports and wildlife action. Use 1/100 second or faster for telephoto portrait images. Use 1/50 second or faster for wider-angle portrait or travel photos where your subject isn’t moving too much. If your subject is completely still, and you have a tripod, use any shutter speed you want.
These are very general suggestions, but they are a good place to start. However, your goal should be to outgrow these tips and develop your own mental model instead. Shutter speed is one of the most intuitive aspects of exposure, and a bit of practice will be enough to help your photographs improve significantly.