Photographs have the ability to not only show the world as it is, but also how we perceive it, and with the right tools, far beyond how the human eye can interpret it. In some ways the camera is inferior to the human eye (which in the wide natural world is far from being all that impressive), but in other ways the camera can be manipulated to capture views of the world that the human eye never could. Examples range from capturing the Milky Way in all of its detail, color and beauty, or freezing the exact moment a Great Blue Heron snatches a fish from the shallows, or capturing movement through long exposures allowing water and sky to soften and streak in beautiful patterns. That last example is the subject which we’ll be diving into more detail on in this article.
Being able to take long exposures requires having a bit of control over both your camera and the light coming in to it. Having some sort of manual or at least semi-manual control setting on the camera is a must to prevent it from ramping up ISO or other settings to keep shutter speeds short. Depending on how fast the moving elements in the photo are moving you may need as little as a half second or as much as several minutes of exposure time to capture the moment desired. For instance, waterfalls and fast-moving streams get soft with some texture in a few seconds, lakes I often try for a minimum of 30 seconds to flatten out the water’s texture, for clouds closer to a minute or more is usually required to get much in the way of moment effects that look like they were intentional.
The featured photo above was captured on Cannon Beach on the Oregon coast. While fading evening light extended the shutter speed some, it was not nearly enough to mist-out the crashing surf enough to increase the contrast between the ocean and the two tall sea stacks which was to be the focus of the image. The addition of a Neutral Density filter (not to be confused with gradient neutral density filters which are not dark throughout the filter’s height) can be used to extend the exposure time beyond what the conditions would otherwise allow. On the featured image I utilized a 6-stop ND filter to push the exposure out to 30 seconds when paired with an extra low ISO at 50 and aperture stopped down to f/13. Had the shot been taken earlier in the day and under clear skies, a much stronger ND strength would have been needed to get the same long exposure in a single shot. The strength of neutral density filters are usually determine in stops, a single stop strength will double the exposure, a 2 stop ND would double it again, 4x the original shutter speed. A 3 or 6 stop ND are good all-around options for moving water, stronger filters are needed for slower moving waters or clouds.
Another example of the interesting effects that can be achieved with ultra long exposures of wave action, the misty fog like look between these polished rocks was created by the rolling waves along the shoreline. When starting out experimenting with very long exposure photography, shots like this are an ideal starting point to practice on. Get a feel for how long of an exposure is needed to get the effect that is desired, how larger and smaller waves affect the look of the misty look. When paired with wider angle views of an interesting background of mountains in the distance or similar it can provide an interesting foreground element to lead the viewer’s eye from the stones all the way through the image to your focal point in the distance. The smooth water between the rocky foreground and distant background focus prevents there to be too many competing elements of varying texture.
Things are easy when the entire photo is either water or solid rock. You can run exposures as long as you want without any worry about undesired movement. However in scenes where there is both desired movement and undesired movement possible in the frame a balance must be found to get the entire image captured in a single frame. While shooting around waterfalls especially, the rushing water can cause all sorts of air currents that will blow leaves and less sturdy elements around. While shooting these falls in the Columbia River Gorge, I opted to stay with the lighter 3-stop ND filter and exposure times of only a few seconds. It was enough to provide plenty of soft water movement, but kept at least most of the surrounding foliage still. Some movement can still be seen in the smaller foreground stems of ferns however. The options here are simple, either keep the shutter speeds a touch faster when there are moving elements, or take two shots, one longer for the desired movement, and a second shot without the ND filter to freeze the movement. Using the power of Photoshop layers, you can easily blend in the areas of one frame into the other to get the best of both short and long exposures. Things can get a little complicated if moving leaves pass over flowing water for example, for tips on handing these difficult editing situations, check out some of my post processing articles.
One thing to note about high-stop ND filters is that they do come with their own difficulties and issues. The first issue is how to focus when less than 1% of light coming into the filter is making it into the camera. Looking through the view finder is nearly pitch black, and using the live view of the camera is almost as useless. In bright light I can sometimes see enough to get a general idea of the composition of the shot, but even my newest full frame DSLR camera bodies have a very difficult time focusing through these filters in full daylight, and even then I often find the accuracy of the focus to be somewhat suspect. Therefore, it is more or less required that the camera be setup, the shot composed, lens focused, and then the filter be put into place. Large square filter setups that allow you to slide the filter into a holder from above that are easier to work with in this situation than a screw-on filter like use. While they are easier to install and remove from their specialty holders, they are also much more bulky and multiple filter holders or adapters will likely be needed. For these reasons I have decided to stick with circular screw in filters. The other issue with very dark ND filters is that they are rarely truly neutral. That is, they do not actually block all light the same and thus create color casts to the resulting images. Some brands tend to cause blue tone casts, others brown/red hues. My 10-stop B+W causes brown/reddish hue to most photos that must be dealt with in post processing. While some long exposures look great as B&W photos, thus quickly eliminating any concern about the color cast, others must be removed in post processing. In rare cases however, the color cast is actually a blessing in disguise. My image from Ashless Pier on the shores of Derwentwater in the Lake District of England would have been a lifeless gray without the added color from the B+W 10-stop. I had originally taken the shot with the intent of converting to monochrome, however after seeing the deep colors that the filter introduced into the resulting image I decided to instead enhance the color instead of trying to neutralize or remove it. Since coming back from that trip, I discovered a new set of filters made by Breakthrough Photography. Their X4 line of filters have become my go-to set for when ultra-color-neutral shots are a must. I now have their 3, 6 and 10 stop ND filters in addition to the Circular Polarizer. If you are looking to start a collection of ND filters, I highly suggest you look into these.
One of my more recent very long exposure shots taken this past fall. Even under bright evening light, the Breakthrough X4 10-stop ND provided very color-neutral long exposures along the banks of the Trinity River in Dallas. While a single 30 second exposure was enough to provide some cloud movement, I took a sequence of 6 of them back to back, adding up to 3 minutes of cloud movement that could then be stacked and blended in Photoshop.
I have thoroughly enjoyed starting to exposure the possibilities of long exposure photography, and plan to find interesting opportunities for capturing both movement and using movement to create interesting looks to my photos in the future. I hope these examples have been able to give a glimpse of what is possible with the long exposure technique and perhaps inspired any photographers reading to explore the possibilities themselves.