Case Study: Silky Water Effect

Some of you may be wondering how people take those pretty waterfall shots where the water looks all white and soft, instead of the hard splashes you see from cameras in Auto mode.

Makiling Botanic Garden, UP Los Baños
Makiling Botanic Garden, UP Los Baños

 

Seoul, South Korea
ISO 100, f/8, 1sec

 

While there are also other parameters you need to take note of, the key here is your camera’s shutter speed. Let’s start with a shot taken in P mode with my camera:

ISO 250, f/3.5, 1/40sec
ISO 250, f/3.5, 1/40sec

With the camera choosing the settings for me, I would normally get this type of picture, as it attempts to capture the water in action. Now, it’s not bad per se, if you’re going for more definition on the falling water as well as the waves it makes. But if you want the silky smooth look, again, you’re going to need tweak the shutter speed.

ISO 250, f/25, 1sec
ISO 250, f/25, 1sec

Now, it’s starting to get interesting. With my camera now switched to shutter priority mode. Setting the camera’s shutter speed, you see the definitions blur significantly. If you look at the settings more closely, you’ll notice that the camera needed to compensate by decreasing the aperture drastically. It just so happened that I took these pictures at around noon-time, so ambient light was quite intense even under the shade. Otherwise, aperture should not have been that low. If you’re satisfied at this stage, you can stop now. But if want some more blur, you have to keep on going with an even slower shutter speed.

 

ISO 250, f/25, 5sec
ISO 250, f/25, 5sec

Ouch. Going for a five second shutter speed in this case resulted in an overexposed shot. I can, of course, try 3 seconds or something, but I wasn’t satisfied by the blur at 5 seconds, so there’s no point. It would have been over for me, but as it has been a bad habit of mine, I overlooked an important parameter that day. I left the ISO setting at 250. With that sunny day, it may not have been the best choice. So, I tweaked that to as low as I can get it.

ISO 100, f/25, 5sec
ISO 100, f/25, 5sec

Going down to ISO 100 gave me a LOT more room to work with. As you can see, even at 5 seconds, the shot was still seriously underexposed. Now, I can really lengthen the exposure duration (decrease the shutter speed even more).

ISO 100, f/25. 30sec
ISO 100, f/25. 30sec

This was as far as my camera could go without going manual with the shutter. If the blur is too much for you at this stage, you can easily try a different speed. There is no rule as to how silky the water should be. It’s totally up to you and your personal taste, as well as the volume of water and strength of the current.

Now, for some limitations:

As you can see in the last picture, you’ve also got some blur going on with some of the leaves. The stream of water keeps hitting them, so they are also in motion. There’s no avoiding it, in this case, but it’s something you need to consider when choosing your shutter speed.

The magnitude of allowances given to me by my Nikon D7000 is not available to all cameras. For example, I used to own a point and shoot Canon which could only go down to 15 seconds and f/8.0. It’s hard to tell whether or not you can get good results with such limited ranges.

With all the long exposures, you won’t be able to get sharp results without a tripod or something firm for the camera to sit on. It would also be best to use a remote trigger or set the camera in timer mode to further minimize camera shake.

Vienna, Austria (2014) ISO 100, f/22. 1/2sec
Vienna, Austria (2014)
ISO 100, f/22. 1/2sec

Sometimes, even DSLR’s end up with overexposed shots. That is where neutral density (ND) filters can come in. We can talk more about filters elsewhere in the course site.

I hope this helps explain a few things. I look forward to seeing you apply these techniques in your own work.