Shutter speed is an essential specification to master to capture good photography. Along with aperture and ISO, it forms the holy trinity of photographic exposure. In this discussion, I will talk about shutter speed and the different aspects of shutter speed that you ought to know to use it more creatively in your photography.
An Introduction to the Basics of Shutter Speed
In straightforward terms, shutter speed denotes the time the shutter curtains remain open for an exposure to be recorded. A typical camera has two shutter curtains.
I am referring to cameras that have a focal plane shutter. Another mechanical shutter, a leaf shutter, is also in use. But they’re not used in digital SLRs. Digital SLRs have focal plane shutters, so we’ll stick to them in this discussion.
When the shutter release button is pressed, a series of activities happen inside the camera. While we’re not going to learn about all of them here in this discussion (that discussion is best kept for another time), we’re going to learn about one specific thing that happens – the movement of the shutter curtains. At first, the first shutter curtain moves, and right after that, the second shutter curtain moves.
The intermittent gap is when the sensor behind the shutter curtain is exposed to light, and the exposure is made. The faster the shutter speed, the quicker the shutter curtains move, and the less time is available to make the exposure. This is the basic functionality of the shutter curtains.
One thing that I need to mention here is that we refer to the speed of the shutter as shutter speed, but in actuality, it’s about the length of time that the shutter curtains remain open. So, it’s somewhat counterintuitive. The faster the shutter speed, the less time the shutter curtains remain open.
Control over shutter speed gives you control over the time the sensor is exposed to light and the exposure itself. The longer the shutter curtains remain open longer the time frame for which the sensor captures light, which has its benefits. On the other hand, faster shutter speeds also have their benefits. We’ll learn about these benefits later.
If you want a beginner’s guide for understanding ISO, check out this: What is ISO in Photography
Shutter Speed Chart
Just like an aperture chart, there is a shutter speed chart. The shutter speed chart reads like this – 1, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, and so on. Reading left to right, every stop halves the light that enters the camera. Every number on that chart is a fraction. So, 1 is 1/1, ½ ¼, and so on. 1000 is one-thousandth of a second. That’s pretty fast. But not nearly as quick as a typical DSLR can fire.
An average DSLR can fire at a fast shutter speed of 1/4000 of a second. And a professional camera can fire at a speed of 1/8000 a second! Now that’s fast!
Relationship Between Shutter Speed and Aperture and ISO
Shutter speed forms a part of the trio of specifications that govern exposure. The other two are aperture and ISO. I have talked about ISO in one of the recent articles. When the shutter speed increases, the aperture and ISO also have to increase.
When the shutter speed increases, the shutter curtains open and close very quickly, and the sensor gets less time to collect light. That means you have to use a larger aperture to compensate for the lack of light. Alternatively, if you don’t open up the aperture, you can push the ISO higher so that the sensor becomes very sensitive to light and offsets for the lack of light collected.
Related Post: What is Aperture in Photography?
An Introduction to The Shutter Priority Mode
You must have heard about the term shutter priority mode. This is one of the creative modes on your camera, along with the aperture priority and the manual mode. In shutter priority mode, you choose the shutter speed while the camera determines the aperture value. That means in this mode, you have partial control over the exposure value. Exposure value is the product of aperture and shutter speed. You control one-half of that aspect.
Controlled shutter speed has creative implications, as we’ll learn in the subsequent segments of this discussion.
The Uses of Slow Shutter Speed
Slow shutter speed is generally referred to as a shutter speed that’s slow enough for light to enter the camera over some time. A shutter speed of ¼ or less is generally considered slow. But that’s relative because if you think a shutter speed of 2 seconds, ¼ will appear faster.
Slow shutter speed has a bunch of creative applications. As you’ve learned, a slow shutter speed means the shutter curtains remain open for extended periods. When that happens, light enters the camera over a long time frame (naturally!). This means you can capture things that occur over time. For example, you can capture a bursting fireworks display, the tail lights of moving vehicles, and a photo of moving water.
To capture long exposures, you have to use a tripod. A tripod is essential to ensure that your camera does not move when the disclosure is being made. Also, ensure that you turn off image stabilization when using a tripod.
Let’s look at a few user case scenarios of slow shutter speed. Let’s say you want to hike in the woods when you stumble upon this beautiful waterfall. You want to take a picture of it. However, a standard fast shutter speed image does not nearly do justice to that beautiful scene.
The idea is pretty, but the water seems frozen in time. This does not give the desired effect. The trick is slowing down the shutter speed and allowing light to enter the camera over time. You will need an ND filter to help you achieve that shot; otherwise, your picture will be overexposed. I will discuss ND filters later in this article.
The Uses of a Fast Shutter Speed
Like there are many uses for a slow shutter speed, there are a bunch of uses for a fast shutter speed. Only your imagination limits you regarding the creative use of shutter speed. In this segment, I shall provide examples of fast shutter speed use cases.
Let’s say that you’re photographing a school soccer game. It’s afternoon, and the light is beautiful, sharp, and crisp. Yes, there are some hard shadows, but the contrast is clean. You decide to capture the moment when a goal is scored. The setting you need is shutter priority mode.
Your shutter settings should be something very fast. Ideally, 1/1000 or higher. Leave your ISO at 100. The camera will detect the aperture value. But in good light, there would never be an issue of aperture. Even f/5.6 will get you decent exposures at 1/1000 shutter speed.
Let’s take another example. Let’s say that you’re photographing a cycling event, and you know that you want to get a shallow depth of field to blur out the busy background. You’re thinking f/4 is the correct aperture.
You also know that you have to pan with the cyclists to ensure the images of the cyclists are perfectly sharp. An average shutter speed of 1/80 to about 1/50 is ideal here. It gives enough time for motion to be recorded while the camera is panning with the cyclists.
Fast shutter speed is all about freezing movement. So anything like capturing water droplets, a bouncing ball to sporting action requires a fast shutter speed.
The Sunny 16 Rule
The Sunny 16 rule is a rule of exposure that deals with a situation when you’re shooting outdoors, and it’s bright and sunny. This rule governs the exposure of a scene where you’re unable to judge what should be the exposure parameters in a situation like this. The Sunny 16 rule is easy to use once you understand how it works.
The Sunny 16 rule states that in a bright sunny situation, your aperture should be set to f/16. Now the shutter speed should be the inverse of the ISO value. Let’s say your ISO is set to 100; the shutter speed should be 1/100 sec.
Taking the Sunny 16 rule as the basis, you can adjust your exposure for various conditions and equipment limitations. Such as, let’s say that your kit lens suffers from diffraction at f/11, and the best aperture is f/8. That means you would prefer not to work at f/16. Using the Sunny 16 guide, you can adjust your exposure to work at your preferred aperture.
Let’s say your preferred aperture is f/8, two stops faster than f/16. That means your ISO or shutter speed should be pushed down by two stops. Let’s say your ISO is already at 100, so you can’t push it down any further. You can push your shutter speed by two stops to ensure that your exposure is balanced. The previous shutter speed was 1/100; you can push it to 1/400 (two stops) to ensure that you have the correct exposure.
The 500 Rule in Astrophotography
The 500 rule is applicable in astrophotography. In astrophotography, estimating the shutter speed is very difficult, considering that if you get it wrong, there is a high chance that the exposure will be too dark, or you could get star trails. The simple solution when capturing star photos is to use the 500 rule.
The 500 rule suggests you can achieve maximum exposure time without capturing star trails. To do that, divide 500 by the focal length you’re using, giving you the longest shutter speed you can achieve without star trails.
The Sunny 16 and 500rulese are just two of the many available rules that help to guess the correct shutter speed in a given situation. Variations are also available that help in other shooting situations.
Use of ND Filters to Manipulate Shutter Speed
The final segment of this article will be about the use of ND filters. Several different filters are used in photography, but we’re going to limit ourselves to only ND or neutral density filters.
Neutral density filters are like sunglasses to your camera. The sole purpose of using them is to limit the amount of light entering the camera. At this stage, you may wonder why you would be limiting the amount of light entering the camera. When you limit the amount of light entering the camera, you can use creative techniques to enhance your photos.
ND filters allow you to shoot at a slower shutter speed. You can use a slower shutter speed with the help of an ND filter to capture a beautiful sunset, a waterfall, a landscape image with the clouds rolling by, and so much more.
A typical ND filter will have the light-stopping power of the filter mentioned on the box and sometimes even on the side of the filter. For example, an ND 1.2 is a four-stop ND filter. Some brands refer to it as an ND 16. In other words, when you use that filter, you can slow down the shutter speed by four stops (1/16th of light enters the camera), allowing the shutter curtains to remain open for up to four stops longer than usual for the exposure. This will enable you to capture moving water over time, slowing the scene and capturing something like a milky effect.
An ND filter also enables you to use a wide aperture in a bright situation and therefore capture a shallow depth of field when it’s not usually possible. Every stop of light you can stop will allow you to open up the aperture by one stop. Let’s say that you have an f/1.8 lens, and it’s very bright outdoors, forcing you to stop down the lens by three to four stops. You can shoot with a three- or four-stop ND filter allowing you to retain the f/1.8 aperture and capture a shallow field depth.
There are different types of ND filters available, and in a separate discussion, I will discuss in detail those and how to use them for the desired result.