In long exposure photography, taking long exposure shots of moving water is not difficult once you learn how to do it. However, it does require a little more technical expertise than people might expect. While it is possible to get a nice shot of moving water with little to no technical knowledge, it will take a lot of trial and error.
In the end, all of that trial and error will only amount to an OK shot that you settled on because you got sick of taking photos.
With shots like these, the composition is the easy part. You set up your shot according to the rule of thirds, set a low angle, maybe have a little foreground interest, and you probably already have a decent shot. The tricky part is setting the exposure, and this is especially true for landscape photographers. Since the lighting can change dramatically from one second to another while shooting outdoors, having an intrinsic understanding of exposure is essential for landscape photographers.
No matter your skill level, my hope is that this article helps you start taking wonderful water shots with confidence.
It’s possible to get long-exposure water shots by resting your camera on some sticks and setting it by the water. That being said, most people prefer to invest in a reasonable assortment of photography tools to help enhance their shots when creating images like this. The following is a list of essentials you should have when venturing out to take these shots.
- Semi-Wide to Wide-Angle Lens: A big part of making epic long-exposure water shots is capturing the scale and placement of the water in the overall environment. On a crop-sensor camera, a 28mm lens or lower is best for these shots. On a full frame, a 50mm lens or lower is fine.
- Tripod: Getting a tripod with a sturdy ball head and independently angled legs is essential will help you to compensate for uneven ground when shooting outdoors.
- ND Filter or Circular Polarizing Filter: If you are shooting water, chances are you will have highlight reflections from the sky. These can blow out an otherwise perfectly exposed image, and these filters can help mitigate that damage. ND filters become even more essential when you want to get the sky in the shot with the water.
Some would say that a remote shutter release is essential as well, but they really aren’t. I find that simply setting your camera to a two-second delay works just as well and saves you from having to carry anything extra.
In addition to the basic gear listed above, it’s also nice to have Cokin-type fader filters for the front of your camera. These filters fit into a square mount you screw onto the front of your lens, and you can find them with an ND gradient or even with unique color gradients. The benefit of having the gradient is that you can have the darker end of the filter over the sky, which can provide a more even exposure.
Knee or hip waders can also be very useful for these shots. Shots taken from the edge of the water can look nice, but it’s an angle many people can relate to. However, walking your camera out into the middle of the stream to take your photo can produce a significantly more dynamic shot.
Lens hoods are also a great thing to have on the shoot. At some angles, you can get a minor glare from the sun that isn’t apparent when you set up the shot, but which gets burned into your images over a long exposure. The hood will help eliminate that flare.
Shutter speed and motion blur
When you look at long-exposure water shots, your eyes are immediately drawn to the velvety, glassy nature of the water. In these shots, water takes on a soft, ethereal texture that is removed from the more realistic-looking background. This is attained by introducing motion blur to the water with slower shutter speeds. In order to get shots that have this effect, it’s important to understand shutter speeds and their effect on both exposure and motion blur.
The shutter speed is the length of time that your sensor (or film for you SLR users) is exposed to the light coming through your lens. Since all images are nothing but light bouncing off objects, a slow shutter speed will allow light from moving objects to hit the sensor at different angles and intensities. This essentially means that you are gathering many images of the moving object and layering them on top of each other. As these different angles of light blend together over the course of a full exposure, they show the moving object over different periods of time, thereby introducing “motion blur.”
Motion blur is what creates the softness of the water, providing it with a unique texture that makes these shots so interesting. Since the rest of the shot is standing still, the effect can be very appealing. Finding the right shutter speed to give you the blur you want will require a little work, and it will depend entirely on how fast the water is moving. Remember, at this stage, you’re just trying to find the right shutter speed to get the blur that will be the centerpiece of your photo.
Generally speaking, it’s good to start at 1/30 for very fast-moving water and around 5 seconds for very slow-moving water. You can adjust your shutter speed onsite to best suit the speed of the water you’re photographing.
ISO and aperture
One of the great benefits of shooting long-exposure water shots is that the very nature of the photo requires you to use the best quality settings for your lens and camera. To get a properly exposed shot that doesn’t blow out highlight detail, you’ll need to limit the power of the light hitting your sensor during the course of the exposure by lowering the sensitivity of your sensor to light and limiting the amount of light that can reach your sensor.
In basic terms, the ISO setting on your camera relates to the sensitivity of the sensor to light. In the days of film cameras, film came in “speeds” that were defined at different ISO values. The International Organization for Standardization developed values like 100, 200, and 1600 to help create a standard that photographers could rely on when purchasing film. ISO 100 is the base ISO for many digital cameras; however Nikon commonly uses ISO 200 as their base ISO.
At base ISO, slower shutter speeds can be used and more light information can saturate the sensor. This results in higher image quality than you could get at higher ISOs, where less light information is hitting the sensor to get a properly exposed shot. You should shoot at the lowest ISO your camera offers when doing shots like this to get longer exposures and better image quality.
When setting your aperture, you should keep a number of things in mind. Higher aperture numbers relate to narrower apertures, while lower aperture numbers relate to wider apertures. Less light hits your sensor when shooting with a narrower aperture, which allows you to take longer exposures. Narrower apertures also use more of the center of your lens than the outer edges, which can equate to higher overall image quality. Narrow apertures also provide a wider depth of field, which means everything will be equally in focus.
Using a low ISO and higher aperture number will help you get longer exposures while also getting higher image quality. However, a very narrow aperture is not a cure-all for long-exposure photography. For example, going past f/16 on most lenses will start to cause light diffraction within your lens. This can contribute to an overall loss of image quality, which is obviously not optimal. If possible, try not to go any higher than f/16 when shooting these types of images.
The first thing you should do is find the fastest shutter speed that allows you to get the blur you’re looking for. This will be your “base” shutter speed value that you can work off. Once you have your base value, set it a little slower to be sure that you’ll get the blur you want. Remember that a blur can look amazing on a three-inch LCD screen but awful when blown up on a print.
Set your ISO to the base ISO for whatever camera you are using, which will be a value of either 100 or 200 on most cameras. Set your aperture somewhere between f/11 and f/16, keeping it as close to f/11 as you can to start. Set your metering mode to something that best suits your environment. If you’re in a forest with an open canopy over the river, you may want to set to evaluative and meter a darker area of the shore. You may not want to use this same metering mode at a wide-open alpine river. Thanks to the histograms and LCDs on common DSLRs, you don’t have to pay much attention to your metering mode, because you can get instant feedback on your exposure.
Taking your shot
If you find that your image is a little too blown out, adjust the f-stop to make it a higher number. If you have a variable ND filter or different types of ND filters on hand, you can also adjust these to allow less light into the lens.
However, if you find that your image is a little too dark, you should use a slower shutter speed or remove/adjust your ND filter. With shots like this on a tripod where motion blur is desirable, there’s no reason to raise your ISO to get a brighter image.
Of course, these settings are specifically for shots that require a wide depth of field. What if you’re looking for a shot that has a very shallow depth of field? After all, this would require you to have your aperture wide open, which introduces more light to the sensor. When more light is introduced to the sensor, it gets harder to get these long-exposure shots without overexposing the shot, but there are a few things you can do to get a shallower depth of field without having a completely blown out shot.
The most important tip for getting properly exposed long-exposure water shots with a shallow depth of field is to have good ND filters. On a reasonably sunny day, your camera will be physically incapable of getting these long-exposure shots while shooting wide open without using an ND filter.
Another great way to get these shots properly exposed while shooting wide open is by focusing on a specific point in the river. When you do this, you’re limiting the area that is gathering light information. This allows you to use a hat or shirt to shade out some of the sun during your exposure.
Putting it all together
The types of weather variables, environments, and general conditions you’ll be shooting in can vary with outdoor shots. Understanding exposure as it relates to retaining motion blur is an essential part of learning how to take long-exposure water photos. Reading a step-by-step analysis of what to do in situations that may never apply to you doesn’t do a whole lot of good. By taking the time to understand how to set exposure while keeping motion blur in mind, you’ll be able to react to any changing situation that the natural world throws at you. This confidence will not only help you have more fun while taking your photos but also help you to take better overall pictures.