Extend the passage of time to create stunning, ethereal landscape images. James Abbott guides you through the world of long-exposure photography using ND filters
Your guide: James Abbott
James is a freelance photographer and photography journalist specialising in creating shooting and editing techniques that help photographers to improve their skills. His first book, The Digital Darkroom: The Definitive Guide to Photo Editing in Adobe Photoshop and Affinity Photo, is on sale now. www.jamesaphoto.co.uk.
Every landscape photographer strives to put their stamp on the locations they shoot, and while most are best shot at a specific time of day to take advantage of the best light possible, one way of finding your unique voice is to take control of exposure times using ND filters.
Lower-strength ND filters can be as simple to use as attaching them to your lens and shooting normally, while the more extreme filters ranging from 6-stops and above require a little more care and attention to ensure correct exposures. In this long-exposure masterclass, we’re going to take a closer look at long-exposure landscapes and how to successfully shoot them using ND filters to achieve a range of effects.
Filter densities explained
Different filter manufacturers use several methods of displaying ND filter densities and these include how many stops of light the filter reduces, which is the easiest, optical density, and ND factor.
Once you buy into a filter system, it pays to familiarise yourself with the method used so you can quickly identify filters.
A tripod is essential for long-exposure photography because the camera must be kept completely still during exposures to avoid camera shake in areas of the scene that should be sharp.
Using a shutter remote allows you to fire the shutter without touching the camera and causing camera shake. They’re also necessary for shooting in Bulb mode to manually hold the shutter open.
Exposure calculator apps
The LEE Stopper and NiSi Filters apps allow you to dial in the standard exposure and will calculate the exposure required for a variety of ND filters including 6, 10 and 15-stop NDs.
If you plan to combine ND filters with graduated ND filters to maintain sky detail, you’ll need a filter holder where 100mm filters slot in place and can be stacked according to requirements.
Variable ND filter
Variable ND filters are a budget option providing a variable density ranging from roughly 1.5 stops to 8 stops, which is controlled by rotating the front part of the filter.
Approaches to long exposure
All landscapes have moving elements, whether that’s grass, water or clouds etc. Many even have a combination of some or all of these factors, so there’s always a huge amount of potential for creative long exposures. The most dramatic, and often interesting, movement can be found in water and clouds, and exposure time itself can produce drastically different results depending on what you’re aiming for.
Scenes with clouds in the sky look great when you use a long exposure to capture them streaking towards the camera, and depending on how fast the clouds are moving the exposure required could be anywhere from 30 seconds to several minutes. Whereas with water, exposures between 1 and 3 seconds provide the most texture and definition in the water, while exposures of 30 seconds and above create a silky water effect in waterfalls and the completely smooth water in lakes and the sea.
The latter is a popular approach when it comes to shooting minimalist images of a tree, for instance, surrounded by silky-smooth water.
Getting the look
One thing that will always make long exposures effective is a static visual element within the scene that remains pin-sharp. Not only does this contrast and accentuate the movement in the scene, it also acts as a visual anchor that avoids images becoming a pure blur and ultimately abstract.
Personal preference will often dictate which exposure time you opt for, but light levels can also be a factor; it’s easier to extend exposure time than reduce it, which is why it’s essential to carry several ND filters with you when shooting landscapes. For instance, when shooting waterfalls, you’ll often be in dark locations so a 3-stop ND filter may allow you to achieve exposure times of 1-15 seconds while shooting in the morning.
However, shooting in the afternoon might require a 6-stop or 10-stop ND to be used to achieve an exposure long enough to blur clouds.
ND filters compared
ND filters come in a range of light-reducing densities, and with screw-in filters you can get variable ND filters with strengths ranging from around 1.5 stops to 8 stops. For ultimate flexibility and control, the four filters that you need to control overall exposure are a polarising filter, a 3-stop ND, a 6-stop ND and a 10-stop ND.
You can buy other densities, but with these four filters you’re covered for practically every eventuality. The four images here were shot in bright conditions so exposure times show a clearer progression of blur as filter strength is increased.
Polarising filter 1/10 sec
Polarisers are often used in combination with ND filters as they remove surface reflections from water and can deepen blue skies, but, with the ability to reduce exposure by up to 1.5 stops, can also be used as a weak ND filter.
3-stop ND 0.8 sec
The humble 3-stop ND filter is arguably the most versatile of all ND filters since it’s ideal for shooting in low light conditions and around golden hour when you wish to achieve a longer exposure but not one that’s several minutes long.
6-stop ND 5 seconds
6-stop ND filters require exposure to be calculated, either by counting stops or using an exposure calculator app. This filter is best used when a 3-stop ND doesn’t extend exposure time enough, but a 10-stop filter makes exposure times unnecessarily long.
10-stop ND 1 minute
10-stop NDs were the first ‘extreme’ ND filter to be released and provide the ability to shoot extremely long exposures in low light conditions, or even exposures that are 30 seconds or longer in bright and sunny conditions.
How to use extreme NDs
Learn how to correctly calculate exposure when using high-density ND filters that throw the standard rules of exposure out of the window
Extreme NDs, Big Stoppers and Little Stoppers are all names you’re likely to have heard of, and in a nutshell, these simply refer to ND filters that reduce light entering lenses by more than 4 stops. ND filters in this category can’t be used like lower-strength NDs where you simply attach them to the lens and shoot as normal; these filters require you to calculate exposure based on what the ‘standard’ exposure should be, then shoot in Bulb mode and manually time exposures if they’re longer than 30 seconds.
Unfortunately, most cameras have a maximum shutter speed/exposure time of 30 seconds, which is often too short when using extreme NDs. Owners of higher-end Fujifilm cameras such as the X-T4, GFX100S and X100V can set exposure times up to 60 minutes in duration so you don’t have to shoot in Blub mode.
For everyone else though, Bulb mode is the key to long-exposure success. On a technical level, a long exposure is essentially any shutter speed that’s too slow for the camera to be handheld without causing camera shake. However, in terms of aesthetics in landscape photography, it’s often not until shutter speeds are around one second that photographers consider exposures to be long exposures.
Exposures up to 30 seconds using extreme NDs can be dealt with by the camera, but beyond this we have to manually time exposures and hold the shutter open in Blub mode, so let’s take a look at how it’s done.
How to calculate correct exposure times
1 Attach ND grads
Securely attach your camera to your tripod to ensure that it can’t move during the exposure and compose the shot. At this stage, attach a filter holder and any ND grads required to maintain sky detail. Manually focus 1/3 of the distance into the scene beyond the foreground for a large depth of field and to lock focus.
2 Identify ‘normal’ exposure
Select aperture priority mode at f/11 with ISO 100 and apply any exposure compensation as required for a correct exposure. The shutter speed here was coming in at 1/4sec, but if it was much slower than this it would have been beneficial to increase ISO to 200 to halve the exposure time.
3 Use a calculator app
Use a free exposure calculator such as the LEE Stopper app or NiSi Filters app. Both allow you to select which filter density you’re using, and you simply need to input the standard exposure time for the app to then give you the exact exposure time required. Both apps feature a timer.
4 Shoot the long exposure
Set the camera to manual mode and if the exposure is longer than 30 seconds, rotate the thumbwheel until Bulb is shown. Make sure aperture and ISO are the same as in step two, and you’ll need to use a shutter remote to release the shutter at the same time as starting the app timer.
5 Reattach filters and shoot
Attach your chosen ND filter and then the graduated ND if you used one. Release the shutter with the remote, at the same time as the app timer, and make sure it locks to hold the shutter open – depending on model. Press the shutter button to end the bulb exposure when the timer ends.
Fake the effect in Photoshop
You can fake the look of ND filters by shooting five to ten exposures of a subject with the camera on a tripod. You then need to sync the raw files in Lightroom before opening all the exposures as Layers in Photoshop. Next, go to Edit>Auto-Align Layers and leave the Projection set to Auto and hit OK.
On the Layers panel left mouse click on the top Layer, hold down Shift and click on the bottom Layer so all are selected, then right mouse click on the Layers and select Convert to Smart Object. Once the Smart Object has processed, go to Layers>Smart Objects>Stack Mode>Median. Once the mode has been applied the image will look like a long exposure.
Finally, flatten the image and crop the edges to remove space left after the image alignment.
The top three filters you need for superb landscape shots