I often use Neutral Density Filters, effectively sunglasses for your camera lens, to lengthen my exposure times and create motion in my images. Occasionally I'm ask how and why I use this technique. So I thought I'd throw up a blog post from my recent visit to Palouse Falls showing a scene shot at progressively longer shutter speeds to show the effect.
All of these images were shot on a tripod with my Sony A7Rii and 16-35mm f/4 lens. I stopped down the aperture and added neutral density filters as needed to lengthen the exposure time.
Freezing Action (Mostly)
This is the fastest shutter speed I used for this section of rapids on the upper Palouse Falls. If you look closely you can see that the water is still blurred, but it still feels pretty static.
So let's start lengthening the exposure time and watch what happens to the flow of the river.
The water still feels pretty frozen to me although it's getting more blurred with each shot. The shutter speeds for this sequence are: 1/60s, 1/50s, 1/40s & 1/30s.
So let's keep getting slower.
More and more motion as we lengthen the shutter speed, but for me, the image is too cluttered by the waves. This really feels like an inbetween. Not fast enough to freeze the water droplets and create drama, but not slow enough to blur and soften the images. The shutter speeds here are: 1/25s, 1/20s, 1/15s & 1/13s
Long Exposure & Soft Water
Time to dive into my happy place, long exposure and soft water. And let's break this into two parts, short long exposure, and medium long exposure.
Short Long Exposure
The shutter speeds for this sequence are: 0.8s, 1.6s & 3.2s. And these are shutter speeds I use a bunch. They are often just about perfect for those iconic beach scenes with the waves streaking back towards the surf.
At these speeds the water has really started to soften and the individual waves and splashes are long gone. And depending on your preference, there's still detail in the flow and the smaller currents in the river. But let's push it a bit further.
Medium Long Exposure
Okay, let's get the pics up first.
Here we have 6s, 13s, 15s & 30s. The character of the river is changing fast now. And determining the "best" is entirely up to personal preference. If I had to choose, I'd say my favorite for this scene might be the 13s one. And as an aside, we also have the clouds which are slowly starting to add motion to the scene as well. But these exposures are a bit short, with these condition, to get dramatic motion in the sky.
Why the Heck
First, I'm drawn to simple, minimalistic compositions and softening the water with long exposure techniques removes some of the distraction of the waves and spray. But second, and in a way more importantly, I'm drawn to the underlying flow of the river. By lengthening the exposure I can start to see the ebb and flow of the river and for me it adds an emotional element to the image. But hey, that's just me.