Creative Field Techniques - Shutter Speed and Water Movement
Recently, I visited Lake Superior in the upper peninsula of Michigan. Using photos shot during my visit, I can demonstrate here how I dramatically altered the appearance of the water by changing only one setting on the camera, the shutter speed (exposure time). Take a look at the photo below. For this shot, I used a fast shutter speed of 1/60. That means the shutter was open for only 1/60 of a second. This was fast enough to just about freeze the water action, but it wasn’t exactly what I was going for.
Instead, I was inspired by the row of pilings and the brooding clouds to create a minimalistic scene using the water and sky as negative space. The water was very agitated and I wanted to smooth it out. To do that, I needed a long exposure between 20 to 30 seconds. Wow, that’s quite a difference from 1/60 of a second! A shutter speed of 25 seconds was used for the shot below. That gave enough time for the water movement to blend together and take on a dreamy appearance.
Remember, the longer the amount of time the shutter is open, the more light that comes in, thus overexposing the scene. In fact, the amount of light coming into the camera is doubled 10 times when going from 1/60 to 25 seconds! That’s a lot of light and normally, the scene would have been rendered completely white. So, how did I avoid overexposing the scene? I had to use a filter in front of my lens. To achieve a shutter speed of 25 seconds, I needed a filter that was dark enough to cut the light in half 10 times (this is called a 10-stop filter and you can see it in the picture below). Simple! Reduce the light with a filter and bring back the same amount of light using a very slower shutter speed. For example, if I had used a filter that cut the light in half three times (3-stop filter), my shutter speed would have been adjusted from 1/60 of a second to 1/8 of a second:
1/60 to 1/30 doubles the light (1 stop)
1/60 to 1/30 to 1/15 doubles the light two times (2 stop)
1/60 to 1/30 to 1/15 to 1/8 doubles the light three times (3 stop)
Below is one more shot, this time using a 2.5-sec shutter speed. You can see more distinct movement in the water in this shot, so it has a different feel to it than the previous one. But still, the shutter speed was slow enough to give it that silky appearance.
I hope this explanation helps you see that by learning how to control the camera’s shutter speeds and using filters, the photographer has valuable creative leverage. And you can also see how a simple adjustment to a camera setting can alter the appearance of a scene dramatically. That’s the beauty of photography, when one scene can provide so many artistic interpretations.
One last thought for the photographers. 10-stop filters are not cheap, but fortunately they are not necessary to achieve your creative goals. You can shoot on overcast days at the beginning or end of the day when there is considerably less sunlight. In the evening, twilight is a beautiful time to capture these long exposure water scenes. It also helps to set the ISO to its lowest setting (typically 100) and close the aperture a bit more (going from f8 to f16 cuts the light in half two times or 2 stops) to help you push that shutter speed into your creative zone.
Thanks for looking on and if you are interested in receiving tutorials in Photoshop or individualized workshops in the field, please check out my website and feel free to contact me at email@example.com.