Friday, March 18, 2011
Silky and Chaotic Water
Once in a while, I have people look at me with glazed over eyes when I have tried to explain slow and fast shutter speeds, and why one might be better in some situations over the other. Well, the other day when I was shooting the tree skirts, I shot some fast moving flood water spilling over the top of an old dam that I think helps illustrate this.
The top shot was taken handheld at 1/20th of a second - which sounds fast, but really isn't. I had a tight grip on the camera and had my shoulder wedged into a railing so the shot would be steady - because at that slow speed even pressing the shutter release too hard will move the camera a bit. I don't shoot hand held long exposures much - models tend to move at just the right speed to not require it, so I called upon some of my rifle shooting/breathing skills to keep the camera steady.
You can see the water cascading over the edge of the dam and appearing really blurred. It looks smooth and silky, and yet the concrete of the dam in the centre is fairly sharp as it is the only stationary object.
In the second shot, I upped the shutter speed on the DSLR to capture a much smaller slice of time. In this case 1/1250th of a second. You can stop motion on most things at that speed: whether it's rushing water, a race car, or an airplane. You can go faster still, but you come up against a barrier of not allowing enough light in the camera to take a good photo as it is opening and closing the shutter too fast.
I had a circular polarizer filter on the lens to reduce the light to make the long exposure in the first shot possible - as keeping the camera shutter open long on a sunny day lets in way too much light. Since I wanted to keep the same angle in the two shots, I didn't remove it. Doing that restricted my setting an even faster speed as the shot would have been too dark. But you can certainly see the difference in the two. Everything is frozen. Silky smooth is now chaotic. Individual droplets are now visible.
Both images have their own appeal, but each have a completely different feel to them. I am partial to the long exposure though because it is something the eye doesn't get to see. :)
Posted by Mike Wood at 08:35