When the light is low the opportunity for slow exposures is best. Bright sunny days are great for high impact landscape photography, but the more subtle and gentle light offers a chance to delve into the dark art of filters and long exposures.
A destination like Iceland is perfect for this kind of photography, with soft light and lots of water to shoot with. Water is a key ingredient to long exposure landscapes because you can enhance the drama of waterfalls or maximise the silky nature of reflections. I love Iceland when it’s covered in snow and the sun is down low.
The end goal is simple, we want an exposure that sits somewhere between 2 seconds and 2 minutes. Depending on the nature of the water movement, it’s speed and patterns, we may find that 2 seconds is more appealing than 2 minutes or vice-versa. Waterfalls turn silky after 2 seconds, and continue to smooth out as you hit 20 seconds or longer. There is no correct exposure here, rather you take a series of shots and see what appeals to your creative aesthetics.
The basic technique is simple enough. You setup a composition with your tripod and a wide lens and lock down pretty much everything. Turn off the autofocus and manually set you focus for a little bit left of infinity. Shoot in Manual and lock in an aperture of f/8, with the ISO dialled down to the minimum. If the natural low ISO for you camera is 200, try to avoid the option to expand the ISO down to 100. The sensor achieves this by sacrificing dynamic range and you may need that later on when it comes to process the image.
At this point you can set the shutter speed to balance your exposure, which will depend on how much light you have and the creative use of filters. The twilight hours offers extremely low light that can generate very long exposures, but we don’t want to be limited to shooting just in these hours. ND filters are the key to pushing beyond the limits of natural light.
ND simply stands for Neutral Density, which is a technical way of saying the filter impacts the entire exposure evenly. It shouldn’t cause colour tinting or retard a selective part of the light spectrum. I like using screw in ND filters. I remove the protective filter first, drop in my ND filter and reassess the exposure.
ND filters come in different strengths. Some reduce your exposure by three stops, six stops or even ten stops. To add confusion, many brands use a different scale to note how intense the affect is. Is a 6 stop ND the same as a 400x ND, or a 1.8 ND? You’ll only ever know for sure through trial and error.
I keep a light three-stop ND in my kit, plus a heavier 6 stop ND. It is possible to combine them, to generate 9 stops, but you will find that unless you buy extremely good quality filters that stacking filters in this way leads to undesirable colour shifts in the final image. Also, you generally want just one ND filter in place so that you have flexibility to apply Graduated ND filters later as well.
The combination of ND strength and how soft the natural is that day will guide you towards an exposure. You can’t always choose to expose for 10 seconds instead of 2 seconds, or vice versa. Sometimes you have to work with what falls out from the filters you have on hand. You can bump up the ISO to reduce an exposure of course, that works just fine even on exposures that run for many minutes.
At this point we have the basics to achieve a long exposure. Ideally we have a cable release to trigger our exposures without shaking the camera/tripod. If not, use a 2 second delay on the trigger to avoid those tiny tremors caused by tapping the shutter button.
Our next trick is selective use of a Graduated ND filter to balance out elements of the scene. Many people get confused between an ND and ND Grad. They both use the same “neutral density” technology to slow down exposures, but the ND Grad has a gentle gradient that drops out the ND effect from one end of the filter to the other. It means you can roughly apply the ND to one half of the frame, for example, and not the other.
This is useful to balance out the reflections over water. The sky is brighter than the reflection because light has bounced off the water and some it is lost in the process. Typically a 3 stop ND Grad gives you a nice result to pull back the detail in the sky, or at least enough to make processing the file much easier.
The usual rules apply with slow shutter photography, in Iceland as anywhere else. You want to work strong foregrounds in addition to a dramatic landscape. Water moving through the foreground and emphasising the slow shutter becomes a powerful tool for composition that is hard to match. Waves breaking around shoreline rocks or a river cutting through a frozen landscape become elements of composition that the eye cannot see, but a camera can.
The combination of a wide lens, slow shutter and getting up close to the subject it the essence of what we aim for. Standing back to capture the width of a waterfall is not always the most compelling composition. Placing the action into one edge of the frame is a good starting point, giving a sense of the composition being “left or right handed”. Our natural tendency is to simply capture everything, stuff it all into a single frame, but often the most impact is achieved by allowing part of the story to dominate the frame.
One of my favourite finds when shooting slow shutters are eddies in the water. If you can get right up close to the waters edge where frothing water or ice flows are swirling in circles you can capture the trail in detail. Experimenting with exposure length is important is such situations, as too little may cut short the swirls, but too long may lose those lines that build detail against the darker water.
It’s the choice between shooting for fine lines that trace the movement of water, and obliterating the motion entirely in favour of a milky absence of movement.
Slow shutter work is very demanding on post-processing, more so than many other forms of photography. You’ve already manipulated the light before it hits the lens, and depending on the quality of your filters there may be some subtle colour shifts happening.
In the Icelandic winter the combination of low sun angle and cloudy days causes some unusual colour shifts anyway. A world painted white with snow and draped in heavy cloud cover tends to over emphasise the UV spectrum, adding a more significant amount of UV and IR light to your exposures than the cameras are designed for.
The other issue impacting your processing task is the low contrast environment that draws us to long exposures. Images can easily look flat and lifeless when taken off the camera, made even worse if the fine detail across the water has been turned to milk instead of motion.
You need to add contrast to make an image pop, but do so carefully to avoid blowing out colours or corrupting the gentle balance of the landscape itself. It’s a fine line to step.
The trick is to work in layers when processing the image, to apply more contrast to some selected areas and less to others. I prefer to avoid increasing saturation in general, but there is one trick that works very well in the Icelandic context. Instead of simply grabbing the saturation tool and giving it a yank, I use a selective colour tool to isolate the jade/aqua hues that I want to emphasise. I bring up both the saturation and exposure for that hue wherever it appears in the frame.
I have to do so with care. The goal is to bring out the natural colours that made the scene so inviting to you int he first place, not to replace a dull and pallid landscape with something artificially dramatic.
The last trick in my bag of slow shutter photography is the advanced features of many DSLR cameras that add frames together into a single RAW file. Multiple Exposure tools on cameras such as the Canon 5D MkIII and Nikon D810 allow you to shoot a handful of frames and stack them together as though they are one.
Using the “Averaging” algorithm in camera I can take a 2 second exposure 9 times over, and hence create an 18 second frame. It’s one way to extend my long exposure without the use of additional ND filters. The effect is usually very convincing, although small gaps between frames can sometimes cause a staggered flow in the elements of motion.
Where possible I still prefer to use a very good ND filter however. One long exposure is a thing of beauty. I love the idea that my camera can see the world in a way that I cannot. With the help of a very solid tripod and some basic filters in my bag we’re going home with images of Icelandic winter that will hold a special place in my life forever.