The camera allows photographers to control time unlike any other device. By manipulating the camera’s shutter speed, the briefest of instants can be frozen in time, from falling raindrops to speeding race cars. Conversely, the camera’s shutter can be held open for extended periods of time to blur the motion of the world. This effect is particularly visible when photographing at night, with the lights of moving traffic forming one long illuminated stream through the night streets. But what about during the day? With ample light for exposure during the daytime, long exposures are more difficult to achieve, as light intensity needs to be reduced to produce the extended shutter speeds that long exposures require. This requires a few pieces of equipment.
The first photographic images ever taken were long exposures by default, due to the lengthy period of time required to expose the early photosensitive materials to a sufficient amount of light. Joseph Nicéphore Niépce’s first photographic image is thought to be at least an eight hour exposure on to a pewter plate taken in 1826 or 1827. Louis Daguerre’s first photo featuring humans is thought to have been a 10 minute exposure of a bustling Paris boulevard. However only two men, a shoe polisher and his customer, remained stationary long enough to appear in the final image.
Today, camera sensors and shutters are advanced enough to capture time in thousandths of a second. Long exposures, on the other hand, are primarily a function of a lack of available light. Think last time you tried to take an image in low light with a camera. Warning lights on the LCD probably would have flashed or the shutter speed number turned red to indicate the probability of the resulting photograph being blurry. The advanced image stabilisation present in many of today’s cameras means that many night photographs that would have been blurry are far less so. But what if you want a long exposure during the day?
What You’ll Need
First and most important piece of gear for long exposures is a tripod. A tripod will ensure that the camera is locked off from all movement, preventing camera blur that may spoil images. There are various tripods available from the entry-level to carbon-fibre professional. What tripod you choose will depend largely on the size and weight of your camera. For a compact system camera or entry-level DSLR, a Vanguard Espod 233AP would be appropriate. For heavier camera/lens combinations, a Manfrotto 190XPROB with 804RC2 head would do the job, able to safely carry a load of 5kg.
The best cameras to use for long exposures are DSLRs, mirrorless cameras or advanced compact cameras. Most of these cameras have the manual exposure modes required for long exposures. If in doubt, consult your instruction manual or a camera specifications internet site.
As will be discussed shortly, a camera that can accept filters is desirable. Compact cameras may be able to accept filters through use of an adaptor and most DSLR lenses have a thread at the front to screw on filters.
Remote Shutter Release
A remote release allows you to activate the shutter without physically touching the camera. Using the camera’s own shutter button while it is attached to the tripod may vibrate the camera very slightly, blurring the final image.
Remote shutter releases take many forms. Some are as simple as a threaded cable that screws into the camera’s shutter button (the Fuji X series and many film cameras can do this). Wireless remotes are available for many DSLRs, as are more complex wired electronic releases that control many of the camera’s exposure functions.
The other option is to use the self-timer function of the camera. Many cameras have a timer setting of 2 seconds precisely for this reason.
Neutral Density Filters
Neutral Density, or ND filters are particularly useful for daytime long exposures. The purpose of these filters is to reduce the intensity of light that hits the camera sensor (or film). Michaels stocks a range of ProMaster Variable ND filters in a variety of sizes to fit most lenses. As the name suggests, these filters can vary the amount of light let through to the camera sensor. These ProMaster Variable NDs have a range of ND3 – ND400. That is equivalent to 1.3–8.6 stops of light.
In camera setting terms, that means if on a hazy day, the scene’s correct exposure at 100 ISO is at f/11 at 1/125 second, we would have to expose the same scene for 2 seconds with a ProMaster Variable ND filter over the lens set at ND400.
Undertaking daytime long exposures is perfectly possible using film, although film is less versatile in some ways. Where you are able to change the ISO value of a digital camera, putting a roll of 36 exposure 400 ISO film in a camera means you are locked to that value until you finish the roll.
Ideally for shooting daytime long exposures with film, you would use slower films, like Fujifilm Velvia 50 colour slide film, Kodak Ektar 100 colour negative or Ilford Pan F 50 black and white film. But there is still more to consider when shooting long exposures with film.
Film suffers what is called reciprocity rate failure, which in simple terms means that film needs a longer exposure time than indicated by the light meter for timed exposures. The information for the amount of exposure correction needed is usually available on the film manufacturer’s website. The technical sheet for Ilford Pan F 50, for instance, indicates that exposures over ½ second require a longer exposure as indicated by a graph.
Choosing a Location
Finding a suitable location can be more difficult than you might imagine. A 1 minute exposure, for instance, of constantly moving traffic in daytime results in a fairly ordinary image of the road and not much more. The same exposure where traffic is constantly stopping and moving would create a more interesting image. Just like the pedestrians stopping and waiting on the steps of Flinders Street Station (above), stationary subjects are as important as blurring motion for long exposures.
Locations with water, such as a beach, river or fountain also make for interesting images. Long exposures of flowing water can be used to transform static drops into blurry streams of continuous water. Long exposures are particularly effective at conveying motion in a way quick snapshots cannot. Rough seas can be transformed into misty pools of water with an other-worldly feel.
Similarly, take a long exposure on a windy day in the bush and the usually static branches of trees will be transformed into a sea of motion. A very different way to see a familiar scene.
Taking long exposures during the daytime is not as simple as placing the camera on automatic and pressing the shutter. The process requires a working knowledge of camera functions and exposures.
First off, it is important to make sure the camera is secure on the tripod and, if you're shooting in a busy area, are mindful of pedestrians and traffic. Compose your image through the viewfinder or screen - articulated LCDs are quite useful when cameras are locked onto tripods.
Determining exposure is probably the most difficult part of the long exposure process. Unfortunately automatic camera modes aren't much use when taking a daytime long exposure, so a combination of in-camera metering and old-fashioned exposure calculation is required.
First off, we need to work out exposure without the ND filter on the lens. To do so, place the camera into aperture priority and set the lens aperture to the largest number, which lets in the least amount of light. On a DSLR kit lens, this is usually f/16 or f/22. Then set the camera ISO to the lowest number, usually 100 or 200. Now look at the camera information screen. It will determine an exposure based on the ISO and aperture you have selected. If it is a sunny day, the shutter speed is likely to read 1/30 or 1/60 second. On an overcast day, the shutter speed may be slower, such as 1/15 second. You might want to take an image at these camera settings to ensure exposure is accurate.
Now comes the calculation part. We want to use the ProMaster Variable ND to limit the amount of light hitting the camera sensor/film. To do so, we need to calculate the exposure with the ProMaster ND set to ND400. It is important the image is composed to your liking, as once the ProMaster Variable ND is put on the lens and set to ND400, seeing anything through the viewfinder or LCD becomes difficult. The ND filter is so effective at blocking out light that it renders the camera's exposure meter ineffective.
Place the ProMaster Variable ND on the lens and the filter to "MAX", which is ND400. This cuts down the light entering the camera by 8.6 stops, meaning the camera shutter must be open over 250x longer to achieve the same exposure. So, if the initial shutter speed reading without the ND filter was 1/30 second, we would need around an 8 second exposure with the ND400 on the camera. How do we work this out? Some people can quickly mentally calculate it, but if you're not gifted with amazing calculatory skills, then there's always an online exposure calculator, such as this oneby Fred Parker.
To use Fred's chart, we find our lens aperture along the top row and initial shutter speed without ND in the column. We then count eight rows up. Each row represents one stop. So if your initial reading is 1/15 second, count 8 boxes up and you find 15 seconds. There are also smartphone apps available for calculating exposure. If you do not want your photography to be reliant on technology, then it is simple to print your own exposure spreadsheet, laminate it and keep it in your camera bag.
Finally, we want to set the camera on to manual mode to be able to control both shutter speed and aperture to get our image. We leave the aperture at the biggest number (f/16, f/22 or similar) and change the shutter speed to the number we calculated in the previous step. The longest defined shutter speed available on cameras is usually 30 seconds. After that, it is referred to as "bulb", meaning the shutter will stay open as long as the shutter button is depressed, or until the camera battery is exhausted!
Pressing the shutter
While it is possible to use the shutter as normal on the camera, pressing the shutter button may move the camera, resulting in image blur. Using a remote release for the camera limits vibrations and means you can stand more comfortably without your finger on the camera shutter should you be shooting in bulb exposure.
Experimentation is the key to attaining a good exposure. Digital cameras make experimentation easy, cheap and almost instant.
Overcast days allow the longest exposures, especially with low ISOs and limited apertures. For example, a decent DSLR set at ISO 100, lens stopped down to f/22 on an overcast day would need around 30–60 seconds of exposure. Shooting in Raw allows even more flexibility, with under and over-exposure able to be partly corrected for in post-processing.
How it was done
The above image of Flinders Street Station is an 34 second exposure taken with a Nikon D300 and 20mm f/2.8 Ai-S Nikkor lens on a weekend afternoon. The image was composed through the LCD using Live View and a meter reading taken at f/11 without the ND filter over the lens. The camera indicated a shutter speed of 1/8 second. The shutter speed 8 stops slower was calculated using an exposure table, which was 30 seconds. The variable ND was placed over the lens and camera set to manual. The lens aperture was left at f/11 and the shutter speed set to BULB. Additionally, the camera's Mirror Lock-up function was used, which reduces the vibrations from the reflex mirror when taking an image. The shutter was triggered using a Nikon MC-36 multi-function remote which includes an LCD counter.
The NEF Raw file was then processed in Adobe Photoshop Lightroom 5, with some basic exposure and distortion correction. The resulting image was then processed through DxO FilmPack 3 to give it a certain colour style.
Links for Inspiration
Berlin-based photographer Robert Herrmann has made a project of daytime long exposures in his 60" slices of present series, using large-format cameras to capture 60 second exposures.
Website Bored Panda presents "30 Breathtaking Examples of Long Exposure Photography", featuring both daytime and night time photography.