Exposure Triangle 1/3: Shutter Speed
When I got my first DSLR(Camera), I shot over 1000 images weekly. it was a dream come true for me and I wanted to capture every moment. My Camera was set to “Auto mode” (I had no idea what happened in “Manual mode” and was not ready to stress myself at that moment). Although I noticed some numbers change on the screen, I still got images I wanted at that time. A time came when I needed to have creative control over some certain parts in my images. For instance, I took pictures of my fan in motion a lot and wondered why the fan blades were captured frozen and I needed to capture the fan in motion.
With all that said, I want to introduce you to the Exposure triangle. Think of it as the key to having creative control over the outcome of your images as photography is all about capturing light. For some of you that studied project management, just as we have scope, time and budget as the key elements, we have Shutter Speed, ISO and Aperture which make up the Exposure triangle.
Let’s use the eyes to describe all 3 elements.
The shutter speed is the time duration our eyes is open to let light enter. The ISO is the sensitivity of rods and cones behind our eyes to the light. And the aperture is our eye’s iris that opens and constricts to control the amount of light entering.
This is the most straight forward element in the exposure triangle i.e., it doesn’t have anything to do with Inverse square law of lighting or any other complicated law. It is simply the time duration of Camera’s shutter opening to let light go through the lens, the aperture and hit the photosensitive surface(film).
It controls the brightness of the image and dramatic effects by either freezing action or blurring motion.
I will walk you through how it controls brightness and then dramatic effects.
Brightness of Image.
“This is the time duration the camera shutter opens for light to enter through the lens”. So, it’s safe to say that the longer the time the more amount of light enters; and the lesser the time the lesser the amount of light entering. Now the camera shutter speed works in seconds and mostly in fractions of seconds i.e. milliseconds. Your choice of shutter speed is dependent on the how the scene is lit and how you want your final image to look.
Taking a set of images in the same scene and changing just the shutter speed either increases or reduces the brightness of the image as can be seen above. But the goal generally is to get well-lit images.
In a dark scene, you have to set your shutter speed to slower shutter speed i.e. 1/100, 1/80. Of course, you have to consider the ISO and the Aperture but we are assuming here that those values have been properly set. Your hand is in constant motion even when holding your camera to capture a moment; and your shutter, closing at anything slower than 1/60 will notice this movement and the final image will be blurry- this is called ‘Camera Shake’ i.e., Camera Shakes occurs when your camera moves while the shutter is open. It is therefore advisable to use a tripod stand when using as a shutter speed slower than 1/60 to avoid the occurrence of Camera Shake.
In brighter scenes for instance, an outdoor scene during a sunny day, you have to set your faster shutter speed 1/500, 1/400.
The shutter speed on an average DSLR ranges from 1/4000 – 30” and in some cases Bulb. Bulb mode gives you the ability to keep your shutter open for as long as it is held down.
It is important to note that in cases of fractions of a second the larger the value the faster the shutter speed for instance 1/4000 is faster than 1/100. Also note that 8” and 30” signifies 8 and 30 seconds of shutter speed respectively.
- Freezing action.
At the beginning of this article I mentioned taking pictures of my rotating fan and the urge to get creative control, the image below is a sample of freezing action. The key is simply shooting at a faster shutter speed that will freeze that water droplet, that car in motion, that bird flapping its wings and keep it still. It depends on what action you want to freeze, in the case of the fan at 1/100, the blades were already frozen.
- Blurring motion
In a scenario when you intend on showing the motion of the blade, i.e. blurring motion, you set your camera to a slower shutter speed depending on what you want. In the case of the fan, I used a shutter speed of 1/10 and the motion blur was already obvious. This is useful in situations where there is need to show that the subject is in motion.
Working with Shutter Speed
For a start I suggest you select Auto Mode on your DSLR and take random images in both dark and bright scenes to observe how the camera updates the shutter speed to achieve the images. You can also work on your shutter speed manually. Personally, I almost never shoot in Auto Mode. The options for changing the shutter speed manually includes changing your camera mode to “Shutter Priority Mode” or “Manual Mode”.
When on Shutter Priority mode, you have the option of selecting the exact shutter speed you want and the camera will sort out the aperture and ISO for you; although there’s an option of setting the ISO manually if you please.
When on Manual mode, you are gifted with the full creative control. i.e. you decide the Shutter speed, ISO, Aperture and so many others.
I always shoot on Manual mode but in situations where you want creative control of mainly the speed, “Shutter Priority mode” is the advisable option. Also, in situations where you are not sure what shutter speed to use, feel free to switch to “Aperture priority mode”. I will explain thoroughly on each of the “Camera mode” in a later article, but for now, what you should know on Aperture priority mode is that the camera selects the shutter speed for you based on your selected aperture. So, when you move from a dark scene to a bright scene the camera changes the shutter speed.
More tips on Shutter Speed
- If you are using a slower shutter speed i.e. below 1/60 a tripod stand will be needed.
- The faster the shutter speed the lesser the amount of light that travels through the lens, the aperture to the photosensitive surface.
- Long exposure i.e. using slow shutter speed is a technique used in shooting night landscapes even if there is no motion the lack of light makes using this essential.
- When the shutter is open, any object in the frame that moves becomes blur (use a shutter speed fast enough to freeze the action).
- You need a faster shutter speed to capture an action closer to you. For instance, if a vehicle speeds right in front of you, you see it for a fraction of second but when that vehicle is farther and moving at the same distance you see it for a longer time, shutter speed works with the speed and the distance of our subjects.
- Chose a shutter speed larger than the focal length of lens. For instance, if you have a lens that is 200mm, 1/250s will be a good shutter speed to select. A lens of 50mm 1/60s is also fine. The focal length has a direct effect on the shutter speed (in non-image stabilized lens) as it can influence the camera shake.
To wrap it all up, shutter speed is an essential part of the “Exposure Triangle” understanding. It will give you a boost in your creativity options. A blur in a picture is not always awful and freezing an action too can be creative.
Keep practicing until you can’t get it wrong.