What Is Shutter Speed?
A few days ago, I went looking for a waterfall. And the fact that I did is important for this blog, because today I’m talking about one of the biggest camera settings out there. It’s called shutter speed. And there’s no better subject to photograph while I’m talking about shutter speed than a waterfall. Now, step one, before I even explain what shutter speed is, I just want to demonstrate how it works by showing you a few sample photos. And the only thing that I changed in each picture is the shutter speed. Here they are. Now, from left to right, a fast shutter speed to a slow shutter speed. Another way to phrase that would be, a short exposure on the left and a long exposure on the right. And immediately you can see that the biggest difference here is how bright the photos are.
the definition of shutter speed
that brings us to the definition of shutter speed. It’s actually pretty simple. There’s something called shutter curtains that sit in front of your camera sensor and block the light. It’s very similar to the shutters on a window; it’s not some fancy terminology. And any time that you take a photo, the shutter curtains move out of the way and allow light to hit your camera sensor. That’s how you get a photo in the first place. Shutter speed is just the length of time that your camera sensor, or your film, ends up exposed to the light. That’s all there is to the definition. But from that definition, you can probably see why those four photos have different brightness levels.
The brightest one, with a long exposure, literally captured more light. The shutter curtains were open for a longer period of time. And then the darkest photo, with a fast shutter speed, was only exposed to the outside world for a brief fraction of a second. And now I’m going to fill in the blanks with the actual shutter speeds that I used here. On the left, I was at 1/100 of a second shutter speed. On the right, I was at 0.4 seconds. And then, of course, there’s the shutter speeds in between. These are all very normal values for something like landscape photography; the longest shutter speed that I used here was 0.4 seconds.
you can set up to thirty second shuter speed on most cameras
Bu you can set up to thirty second shuter speed on most cameras today – and, in fact, with a special remote accessory, you can extend that without any real limit. And even though my shortest exposure here was 1/100 of a second, you can set 1/4000 of a second on most cameras – and even 1/8000 on many of them. That’s just insanely fast – and also very dark, because you’re only capturing light for 1/8000 of a second. You just won’t get very much of it. So, why does the range need to be so large – 1/8000 of a second all the way to 30 seconds? The basic answer is just that some places are brighter than others. If you’re camping out under the full moon, for example, you don’t have that much light to work with. You’ll probably need a very long exposure just to capture much of a photo in the first place. Like this photo, which I took at 30 seconds. But then the next morning, you wake up, and the sun is bright.
In that case, you’ll need a much shorter exposure. Anything like 30 seconds, and your entire photo is just going to be white – totally overexposed. Here, in this example, I used a shutter speed of 1/800th of a second. Now, both photos are properly exposed, but that was only possible because I used my shutter speed to compensate for the available light. So, hopefully that’s a good demonstration of how and why shutter speed affects the amount of light that you capture. It’s not the only way to change how much light you capture, but it definitely is one of the most important. Let’s jump back to those waterfall photos again. You might notice one more difference between them, especially when I zoom in. The motion in the waterfall is different. The water droplets in the first photo are almost frozen in place. By comparison, the later photos have increasingly more motion blur. So, why is this? Well, remember how shutter speed works at a fundamental level.
anything that moves a significant amount during your exposure will be blurry
It’s the amount of time that your camera sensor is exposed to the outside world. So, if you think about it, anything that moves a significant amount during your exposure will not be pin sharp in the photo. It’ll kind of have a ghost behind it, like the water droplets do here. And even something that moves slowly can still be blurry if your shutter speed is long enough. One of the more famous examples is the Milky Way at night. The stars are obviously moving very slowly across the sky, but even then, if I use something crazy like a 5-minute shutter speed, I can get very blurry stars in my photo. But let’s look at a more typical example. A really easy one is something like a ceiling fan that’s moving at a constant rate. If I take one photo at a fast shutter speed, like 1/800th of a second, the fan looks almost motionless. It’s not actually motionless, but it appears that way in the photo. If I take another photo at, say, 1/50th of a second, we’re getting a lot more motion blur. And if I go all the way to 1/3 of a second, it doesn’t even look like there are fan blades any more. It’s just one giant blur. Still, the light bulbs in the center are totally sharp because they didn’t move during the exposure. Now, you’re probably already thinking about how much creativity this unleashes for the real world.
You can use long exposures to capture amazing photos of something like the ocean, or fireworks, or really anything that moves. And you can use fast shutter speeds to get pin-sharp photos of subjects like sports or wildlife. But before I go into all that, I just want to make a quick side note. Normally, these three photos would have had huge differences in how bright they are. In this demonstration, I corrected for that with two other camera settings: aperture and ISO. I won’t talk about them in this blog, but I’ll explain them in some future blogs because they’re all very closely connected. And let me jump back to another example photo. If you can, try to guess what shutter speed I used here. I know it’s early to throw out a pop quiz, but it really helps to look at a photo and try to figure out what camera settings the photographer used. Ready? My shutter speed here was exactly one second.
And there are some clues. First off, there’s definitely motion blur in this picture. You can see all the streaking in the foreground, and the waves in the background definitely are not pin sharp. And that’s because one second is a pretty long shutter speed – but it’s also not too long. We do still have some shapes in the water, and that’s pretty clear. I mean, if this were something like a 30 second shutter speed, you’d have more than just one wave crashing ashore. Here’s another ocean photo, but this time with 30 seconds. Huge difference. The water barely even looks like water in this photo! It really looks like someone here turned on a fog machine. And that’s even more true in this next photo – also 30 seconds. Here, it was just wave after wave crashing onto the shore. And the result looks like nothing we would ever see in our day-by-day life. That’s one of the huge powers of shutter speed – but it’s also a potential source of blurry photos. If you’re photographing some fast-moving subject that you want completely sharp, like a bird flying through the sky, you need to be very careful that your shutter speed is fast enough. One tenth of a second, for example, won’t cut it. You’ll get a blurry photo every time. And even if your subject is completely motionless, how often are you handholding your camera rather than using a tripod? Because no one can hold their camera perfectly steady without any movement. And, of course, camera movement makes your photos blurry. So then,
what shutter speeds are safe?
That depends on four different factors.
1. how fast is your subject moving?
Pretty self-explanatory. If you’re photographing a race car, you’ll obviously need a faster shutter speed then if you’re photographing a turtle.
2. how stable is your camera?
There’s a big difference between a tripod, a monopod, handholding your camera, and even handholding from a helicopter. And there’s also some cameras or lenses with “image stabilization” – and this compensates and affects how much camera shake you actually capture.
3. how far zoomed in is your lens, and how much are you cropped?
In either case, when you’re magnifying your subject, you also magnify the blur in your photo. So, you’ll need a faster shutter speed in order to compensate.
4. how close are you to your subject?
If you get extremely close to what you’re photographing, just a small amount of movement – either from your camera or from your subject – can result in a huge amount of blur. And those are the four! That’s really all the background that you need to know before going out and testing this yourself. But some photographers may still want some more specific recommendations. If you do, the basic rule that you’ll hear about is to
use a shutter speed of 1/(focal length)
So if you’re using a 50mm lens, use a shutter speed of 1/50 of a second or faster. I don’t love this rule, personally. I don’t think that it’s flexible enough to deal with the huge variety of things that photographers shoot – and, a lot of times, you’ll still get blurry photos when you use it. But if you’re a complete beginner at shutter speed, and you have no idea where to start, it will at least get you into the right ballpark. Still, it’s no substitute for practice. At the end of the day, you just need to go out there and develop your own internal sense of what shutter speeds to use in a given situation. And I’ll be frank here – it’s not always easy. If it’s dark out, and you’re taking pictures of a moving subject, you’re kind of facing conflicting goals here. You will want a long exposure in order to capture a lot of light, but you can’t use a long exposure, or your subject is going to look blurry.
shutter speed is not the only camera setting related to exposure
shutter speed is not the only camera setting available. Two of the others, which I briefly mentioned earlier in this blog, are aperture and ISO. And those are complicated topics in their own right, so they’ll be the next two blog in our series about exposure. But for now, hopefully, you have a good background at least on shutter speed. And the five-second recap is: it changes how much light you capture, and how much motion blur. Obviously, internalizing that and picking the right shutter speed is a bit more complicated, but that’s why my motto is always just to keep practicing. That’s the best way to learn anything in photography, shutter speed included.