Creative photography with long exposures
Long exposure photography becomes a necessity when there is little light, like before sunrise, after sunset or during the night. In this post however I would like to discuss the use of filters to deliberately use long exposure, so we obtain effects that otherwise would not be possible. This can be a lot of fun and sometimes quite surprising.
What equipment do you need?
Besides your camera you will need two more things: a tripod and a Neutral Density filter.
I can’t state enough that a good tripod with a good tripod head is the best investment you can make after your camera and lenses. Almost every landscape photo I take, makes use of my tripod. The advantages of a good tripod are:
– There’s no risk of motion blur, whatever shutter speed I set.
– I can use low ISO, usually ISO 100, so there will be less noise in the photo.
– I can use bracketed exposures, that is 5 different exposures ranging from -2 stops to +2 stops. I can put the 5 exposures together in an HDR later in Lightroom or Photoshop.
– and last, but probably the most important advantage: it slows me down… It takes more time to compose the image, so I give it more thought. I have more time to look at the landscape, take it in, and decide what photo I want to take. It becomes a more deliberate act. And for me that has improved my photography.
The second accessory you need is a neutral density filter. This is mainly a piece of dark glass and therefore it will take longer for a certain amount of light to pass through it. They come in different shades, like 3-stop and 10-stop, and will have different names depending on the manufacturer. There is the square format that you set in a holder in front of your lens or the circular format that you can screw on your lens. Three stops means that you will need a shutter speed eight times longer than what you would have needed without the ND filter. With a 10-stop filter filter the shutter speed will be a 1024 times. Remember that one stop means double or half the amount of light.
Why use a ND filter?
Why would you use an ND filter or better, why would you use a longer exposure time? During a long exposure, what is not moving will remain as in a normal photo. If there is anything that moves, like water or a branch with leaves, that will become blurred. So we can play with having some parts in the photo that are blurry and other parts that remain sharp. This can have surprising effects and is not always easy to imagine before you have taken the photo.
Now let’s take a look at a few examples. I took this photo at sunset in Sardinia – Italy. Using a long exposure, thanks to a 10-stop ND filter, I was able to show the movement of the clouds. They now all seem to point to the centre of the horizon, like a vanishing point.
Another example is this photo I took on Chapman’s Peak – South Africa. This time I wanted to show the curves in the road that winds along the coast by using the lights of the cars that passed on the road. The sun had just gone down and with a long exposure I managed to capture the light trails of a few cars, and enough light of the sky at dusk. Also here you can see the movement of the clouds.
ND filters can also help you to transmit a sense of calm. With the waves crushing on the rocks a fast exposure, freezing the movement of the water would have made it a very busy scene. Using an ND filter and thus using a long exposure make the rocks stand out and the water is softer now. This creates a beautiful contrast between the two and simplifies the composition. I took this photo in during midday with strong light, so even a 10-stop ND filter can only make a 8-10 second exposure in this case. If you need longer exposures, you will need to stack filters (beware of vignetting though) or wait until later…
You can also use a ND filter and do a really long exposure, so the waves in the sea become like smoke. Together with something that remain sharp and in focus, like the pebbles in the photo below, they form an interesting combination.
There are many uses for a ND filter and it gives you more possibilities to express yourself. Just play around with one. The effect is often difficult to foresee, so try and then try some more.
One last tip: especially with a strong ND like a 10-stop, it might be hard or even impossible to focus. Use Live View, open your aperture completely (low f/ number) and a long shutter time. Now you should be able to focus using Live View. Otherwise, your only chance is to unscrew your filter, focus, set it to Manual focus so it won’t change focus, put the filter back on and take your photo.
Show me some of your long exposures. I’d love to have a look. If you want to know more, leave a comment below.