Mastering the Basics: Shutter Speed in Digital Photography
From humble beginnings to the contemporary engineering of today, the camera has come a long way in a relatively short space of time. However, much of the basic anatomy of many early cameras has carried through to the present day. The interchangeable metal Waterhouse diaphragm, for example, has evolved into the modern aperture mechanism. This means that many of the concepts used to create a modern photographic image have had a long and enduring history.
Like countless photographic pioneers, photographers today predominantly rely on shutter speed, aperture and ISO to control the outcome of an image in-camera. And while shooting in Auto mode is a useful option, harnessing the basic tools of exposure broadens the scope for creative photography. In this series, we'll have a look at the basics of shutter speed, aperture and ISO - starting here with shutter speed.
What Does Exposure Mean in Photography?
When the shutter button is pressed, the many complex mechanisms inside a camera body trigger to permit a controlled amount of light to reach the sensor, resulting in the recording of an image. Exposure is a phrase that articulates this process in two ways:
it describes the quality of light in a complete photograph eg. overexposure or underexposure, good exposure or bad exposure
it relates to the duration of the shutter speed when the photo is being made eg. a 1-second exposure or a long exposure
There is also a more casual use of the term exposure. In general conversation, making an exposure simply refers to the act of making a photograph.
What is a Good/Bad Exposure?
The definition of good and bad exposures is subjective. However, the general understanding of a good exposure is a photograph with a pleasing balance of light and dark with no unwanted washed-out details or overly dense shadows. A bad exposure has too many qualities deemed undesirable by the photographer or audience - unintended impenetrable shadows or overblown bright features, for example.
What is Shutter Speed?
When the shutter button is pressed, the shutter inside the camera opens, permitting light through to the camera sensor for a predetermined amount of time. Shutter speed refers to the duration the shutter exposes the sensor to light. This means that the shutter is responsible for two particular things: controlling the brightness/darkness of a photo and creating dramatic effects by freezing action or rendering blurred motion.
How it Works: the Shutter Speed Mechanism
There are two types of shutters - mechanical and electronic. In mechanical shutters, the two most common configurations are the focal plane shutter and the leaf shutter. The focal-plane shutter is positioned within the camera body, just in front of the sensor. The mechanism works by opening one curtain to begin an exposure and closing another curtain to end it. For slower shutter speeds, a forward curtain in the focal plane shutter opens and the camera sensor is entirely exposed to light. When the set shutter speed time expires, a second curtain closes the sensor off, completing the exposure. Faster shutter speeds are achieved in a focal plane shutter with a travelling slit moving across the sensor, permitting light to be converted into a photographic image in a rapid movement.
Unlike focal plane shutters, leaf shutter configurations are usually located within the lens, rather than inside the body of the camera. Made up of a number of thin, overlapping blades arranged in a circular pattern, the leaf shutter opens up in an oscillating fashion to permit light through to the sensor. Leaf shutters are more compact and durable, but they are typically not capable of reaching shutter speeds as high as modern focal plane shutters.
Electronic shutter systems work a little differently. In basic terms, when the shutter button is depressed, the sensor switches on to commence the exposure line-by-line and switches off again to complete the process. Nevertheless, the duration the sensor is active is still called the shutter speed.
Electronic shutters are silent, have higher shutter speeds and can minimise the camera shake seen with mechanical shutters. However, flash synch speeds are much lower, and they don't perform well under flickering lights.
How is Shutter Speed Expressed?
On a camera, a selected shutter speed can be viewed on the LCD screen, on the rear monitor and through the viewfinder. Shutter speed is written in seconds or fractions of a second: 1/100, 1/4 and 1/500 for example. Written in long-form 1/100 means one one-hundredth of a second, 1/4 means one-quarter of a second and 1/500 means one five-hundredth of a second.
In-camera, shutter speeds or time values can present differently on the LCD screen from brand to brand. Typically, values ranging from 1/8000s to 1/4s only indicate the denominator of the fractional shutter speed. For example, 1/8000s is indicated as 8000 in-camera while 4 indicates 1/4 of a second.
At slower shutter speeds, the time value or shutter speed is indicated with the double prime symbol:
0"3 - 0.3 seconds 0"4 - 0.4 seconds 0"5 - half a second 0"6 - 0.6 seconds 0"7 - 0.7 seconds 0"8 - 0.8 seconds
1" - 1 second 1"3 - 1.3 second 1"6 - 1.6 seconds 2" - 2 seconds 2"5 - 2.5 seconds 3"2 - 3.2 seconds
From around the 3.2 second mark, each value is counted as a rounded number of seconds, from 4, 5, 6 and 8, (expressed as 4", 5", 6" and 8") up to 13, 15, 20, 25 and 30 (expressed as 13", 15", 20" 25"and 30"). So 4" means 4 seconds of exposure, and 30" equates to a 30-second exposure.
How Does Shutter Speed Affect an Image?
From freezing high-speed jets to capturing star trails, shutter speed impacts the duration a camera sensor is exposed to light. A fast shutter speed can stop movement for sharp renderings of a moment. A slow or long shutter speed records motion for a greater length of time, translating any moving subject into varying degrees of blur. In average conditions, Auto mode will aim to freeze movement as much as possible, creating a visually sharp image. But adjusting the shutter speed manually in Shutter Priority or Manual mode opens up many more opportunities s for creative photography.
Different shutter speeds create different visual outcomes. Faster shutter speeds will freeze motion, while slower shutter speeds record blur from camera movement, camera shake and subject movement. The quicker the shutter speed, the less blur. Some subjects (eg. flowing water) generate unique effects when photographed with a prolonged exposure, while short or fast shutter speeds are ideal for capturing sharp images of subjects in motion. Other techniques like ICM (Intentional Camera Movement) also make use of slow shutter speeds to create abstract renderings of subjects.
Shutter speed also regulates the amount of light that reaches a camera sensor, impacting the overall brightness/darkness of a photograph. A long exposure permits more light to reach the sensor, resulting in a brighter image. For shorter exposures, less light reaches the sensor, so the resulting image will be darker.
In brief: Faster shutter speeds will freeze motion, and slower shutter speeds record blur. A long exposure permits more light to reach the sensor, resulting in a brighter image. For shorter exposures, less light reaches the sensor, so the image will be darker.
How to Adjust the Shutter Speed on a Camera
Shutter speed and other modes are selected differently depending on the camera. Switching to Shutter Priority mode enables the manual adjustment of the shutter speed while the camera compensates automatically by setting the Aperture for adequate exposure. In Manual mode, shutter speed and aperture can be adjusted by the photographer for greater control over the image outcome. ISO can be placed in either auto mode or manual mode within Shutter Priority and Manual mode.
Changing Shutter Speed on a Canon Camera
For Canon cameras, TV mode (Shutter Priority) and M (Manual mode) are available on the mode dial. Once in TV mode or M mode, the shutter speed is selected via the Main Dial, and the active shutter speed appears on the LCD panel.
Changing Shutter Speed on a Nikon Camera
To adjust the shutter speed via Manual mode on a Nikon camera, rotate the Mode Dial to M. A specific shutter speed is selected by rotating the command dial (right for faster speeds, left for slower). To use Shutter-Priority Auto, switch the Mode Dial to S. Rotate the command dial to choose the desired shutter speed (rotate right for faster speeds, left for slower speeds).
Changing Shutter Speed on a Sony Camera
To put a Sony camera into Manual or Shutter Priority, turn the mode dial to M or S respectively. Then turn the main dial left or right to increase or decrease the shutter speed.
Automatic Scene Modes
In addition to Manual and Shutter Priority Modes, many cameras also offer specialised camera settings. Automatic scene modes typically include presets designed for action, portraiture, night portraiture, landscapes and macro photography. For example, Action mode or Sport mode boosts ISO and sets a fast shutter speed to capture action shots. However, although these presets are handy, they can often fall short in unique situations where Manual or Shutter Priority modes are more flexible.
Shutter Speed, Aperture and ISO
Along with shutter speed, aperture and ISO are the other two key components of exposure. The aperture is the opening in a lens through which light passes to enter the camera. A larger aperture opening permits more light but renders less depth of field (less in focus). A smaller aperture reduces the light reaching the sensor but allows for more depth of field (more in focus).
Somewhat confusingly, an aperture with a smaller opening is designated by a larger f-number. An aperture with a larger opening is designated a smaller f-number. So an aperture of f/2.8 is physically larger than the opening in an aperture of f/16.
ISO defines the amplification of information received when light reaches the sensor. A higher ISO value (like ISO 800) amplifies light much more than a low ISO value like ISO 100. However, the higher the ISO value, the noisier or grainer the photograph.
When actively adjusted in conjunction, ISO, aperture and shutter speed can capture images with more authority than in Auto mode. This can be ideal if a photographer needs to manipulate different aspects of an exposure to achieve the desired effect. For example, in a scenario where a faster shutter speed is required for freezing subjects in lower light conditions, increasing the ISO value can amplify the information gathered by the sensor, helping to create a brighter image overall without compromising the shutter speed. In this same scenario, the aperture can also be opened up to permit more light through to the sensor.
Shutter speed is often best determined by the situation and the available light. But in conditions that require a longer shutter speed, hand-holding a camera can create blur from physical movements, also known as camera shake. To avoid unwanted blur caused by camera shake, one method is to try not to let the shutter speed dip below the focal length of the lens. For example, when using a zoom lens at 200mm, keep the shutter at 1/250s or above. For a prime 50mm lens, maintain a shutter speed of 1/60s or above.
On a lens with Image Stabilization (IS), Vibration Reduction (VR) or Vibration Control (VC) the shutter speed can be decreased a little lower. Other options for alleviating camera shake in situations that demand a longer exposure include using a flash or other lighting, a tripod and/or a remote camera trigger or shutter release.
Overexposure and Underexposure
Overexposure occurs when an excessive amount of light makes contact with the sensor, creating overly bright images. In well-lit situations, too much light with a long shutter speed can result in overexposure. For example, making ICM photography relies on longer shutter speeds, so images can become washed out when taken on a sunny day.
There are a couple of ways to ease the effects of overexposure: boost the shutter speed, close the aperture down and/or reduce the ISO. Using a Neutral Density (ND) filter is also useful for cutting down on the light that reaches the sensor during a long exposure, and working in the shade, on overcast days, or in the early morning or evening will help keep details from being lost in overexposure.
Underexposure, the opposite of overexposure, occurs when the shutter speed is set too high, making undesirably dark images. This underexposure occurs because less light is permitted to reach the sensor during a fast exposure, causing murky images. To fix this issue, shoot at a slower shutter speed, adjust lighting (where possible), boost the ISO value and/or open the aperture to capture more light.
Selecting the Right Shutter Speed for the Job
Shutter speed selection comes down to the available equipment, surrounding conditions, experience and the desired outcome of an image. However, many situations can be pre-empted by referring to recommended shutter speeds as a starting point.
High-Speed Action - 1/4000
High-action subject matter demands rapid shutter speeds. The faster the shutter speed, the sharper the subject. To capture or freeze a fast-moving subject with as little blur as possible, start with a shutter speed of 1/4000s. Scenarios with high-speed subjects in action can include birds in flight, vehicle sports or aircraft displays at air shows. However, a shutter speed like 1/4000s permits very little light to reach the sensor, so aim for well-lit conditions and increase the ISO value and/or open the aperture. Avoid going below 1/1000 when trying to freeze highly active subjects while hand-holding.
Moderately Fast Action - 1/1000
Subjects like athletes in action may not require the shutter speeds needed for high-speed photography. In these situations, starting with a shutter speed of 1/1000s can do the trick, allowing more light to reach the sensor, and facilitating a lower ISO setting for less image noise.
Landscape Photography - 1/250
Landscape photography doesn't demand as higher shutter speeds as action photography because motion is reduced considerably. In sunny conditions at midday, starting with a shutter speed of 1/250s will help gauge the exposure quality of the landscape. If initial shots look overexposed (too bright) then increase the shutter speed value to a higher setting. If the initial shots are underexposed (too dark) then reduce the shutter speed. Aperture and ISO can also be adjusted to accommodate lighting conditions in Manual mode and an ND filter can cut down on light entering the camera, facilitating a longer shutter speed for misty water effects.
Panning Photography - 1/125
Panning involves keeping the lens square with a subject in motion while making an exposure, resulting in a unique rendering of movement. Because panning creates a visual sense of motion through blurred movement, a slower shutter speed is required.
To pan with a faster subject (fast-travelling cars, birds in flight etc) start at a shutter speed of around 1/125s and take a few test shots. For greater motion blur, lengthen the duration of the shutter speed. For less motion blur, decrease the shutter speed. To pan with slower subjects (bike riders, joggers etc), try a shutter speed of 1/60s and go from there.
ICM Photography - 1/15
ICM stands for Intentional Camera Movement. By selecting a slower shutter speed and physically moving the camera during exposure, ICM photographers create intricate abstract renderings of both moving and static subject matter. A shutter speed above 1/125 will reduce blurred motion, so maintain a shutter speed below 1/15 to start with. For more abstraction, lengthen the shutter speed and make incremental test shots. Depending on the lighting conditions, ICM photographers can use shutter speeds as low as 30" to create abstract renderings.
Blurred Water - 1/15
Blurred water effects are popular in landscape photography. To make a blurred water effect in Shutter Priority mode, set up a tripod and camera and make a few test exposures at about 1/15s. From there, increase or decrease the shutter speed depending on the conditions and the desired outcome - the longer the exposure duration, the more abstract the moving water will be.
Waterfalls, rivers and beaches work well as subjects for blurred water photography because they have active aquatic elements that contrast with the rest of a static landscape. Depending on the time of day and weather conditions, having an ND filter on hand can be highly useful, as long exposures without a filter can produce overexposed images.
Light Painting and Car Trails - 1"
Light painting and car trail photography are two ways to make use of bright light sources at night. The darkness isolates illuminated subjects so light sources take on a life of their own. Light painting involves moving a light source around within the view of the camera over the duration of a long exposure. Light painting photographers usually work at night, although places that are shielded from daylight like caves or sheds are also adequate. Sparklers, flaming steel wool, torches, glow sticks, fire poi and LED lights are all good sources of illumination for light painting.
Car trails are captured as cars pass through landscapes at night. A photographer sets up near a roadway and uses a long exposure to record the glowing headlights and tail lights of cars and trucks. Aircraft lights or bike lights can also be photographed at night to a similar effect.
Long exposure is required to capture both light painting and car trails. A shutter speed of 1" is a good start, with a gradual decrease of shutter speed guided by test shots. Like ICM, it's not uncommon to decrease a shutter speed to as low as 30" to get the full effect of car trail photography.
Star Trail Photography - Bulb Mode
Star trail photography is the photography of stars as they appear to shift in the night sky. By using an extended exposure, the camera tracks the paths of the stars as the Earth rotates. There are two ways to make star trail photography, the first is to record the stars' movement with a long exposure. The second method involves blending a significant number of photographs taken over time to create a final star trail image in editing.
To make a star trail photograph in-camera, many photographers use a camera's Bulb function. Typical exposures for star trail photography can range from 15 minutes to several hours, depending on the desired length of the star trail arcs, so a mechanism is needed to keep the shutter open for prolonged periods of time. With Manual mode engaged, Bulb is selected by scrolling through the lower limits of the shutter speed range in-camera. An aperture of around f/2.8 to f/5.6 and an ISO value from ISO 640 are good starting points.
Like any other shutter setting, the Bulb exposure then is initiated by pressing the shutter button. Depending on the camera system, Bulb will either keep the shutter open until the photographer presses the shutter again, or the limitations of the camera system are reached. Some camera configurations will only permit Bulb exposures up to 30 minutes, while others will last as long as the battery life of the camera. A shutter release cable or remote can also be used to open and subsequently close the shutter without bumping the camera mid-exposure.
Shutter Speed with Flash
A flash provides a burst of light that lasts for a fraction of a second, somewhere in the area of 1/1000s or faster. However, due to the nature of standard focal-plane shutters, a photographer will generally only be able to use shutter speeds up to 1/250s unless high-speed sync (HSS) capabilities are equipped.
In flash photography, the shutter speed affects the amount of ambient light captured in an image, while the aperture and ISO dictate the intensity of the flash. Shooting at night without a flash usually renders overly dark results. Adding a single flash will illuminate a subject and foreground with a standard exposure of 1/250s, but the background will remain dark. However, a reduced shutter speed will often enable a photographer to coax more visual information out of a background, capturing ambient light while the flash illuminates the foreground and subject. This is useful for light painting or recording a sharp foreground and a balanced background in low light conditions. By slowing the shutter speed, the camera will record ambient light as well as the subject frozen by the flash activation. This method is called dragging the shutter.
Another way to apply the shutter drag method is to create ghost-like portraits. Light and compose a sitter under a flash with a modelling light in an otherwise darkened studio. Take some test shots to determine the aperture for adequate shadows and highlights. Set the shutter speed for around 1 second. Instruct the subject to begin moving as soon as the shutter is fired and take a photograph. The longer the shutter speed, the more movement is recorded after the flash. This shutter drag method captures a sharp likeness of the portrait sitter - but as the illumination of the flash dies and the exposure continues, the movements of the sitter will render a ghostly double-exposure effect in-camera.
How to Determine the Right Shutter Speed
The best way to determine the right shutter speed depends on the desired outcome of an image. In digital photography, a photographer can make test shots to immediately determine the right exposure for an image. However, knowing the basics of shutter speed manipulation will boost the rate of successful photographs and cut down on prep time.
Whether in the field or planning weeks in advance, the first step to determining shutter speed is visualization. Visualization is when abstract ideas knit together to inform artistic action. Consider motion, brightness, darkness, sharpness and depth of field. How should movement be conveyed within a still medium like photography? What equipment is needed? Should the image be bright, dark, or an even average? For example, a tack-sharp image of a dewdrop on a flower petal in the bright morning light requires a faster exposure combined and a smaller aperture depending on the desired depth of field.
On the other end of the spectrum, capturing the light trails of cars travelling down a highway at night demands a much longer shutter speed. While some photographic opportunities occur unexpectantly, much of the foundation of photographic practice comes down to at least some degree of planning.