Why Long Exposure?
What I love about long-exposure photography is the combination of the sharp details along with blurred water and/or clouds. In the shot below you can see the sand is very sharp, the water by the shore is white and silky, and the clouds are softer. That's due to a 25 second exposure. It's this combination of soft and sharp that makes long exposure photography interesting. It's also something you can't do with an iPhone, and it takes practice. How and when you use it is the artistry.
Recently, I created the image above and posted it to social media. The image garnered a lot of positive feedback and requests for information about the process used to create the image. In this blog I'll discuss long exposure photography, the equipment I used, the techniques and some of the post-processing involved. Perhaps the most important part was the vision to see the image in my head before it was taken.
Location and Assessment
This iPhone shot shows you what the light and ocean looked like when I arrived at Torrance Beach, located in L.A.'s South Bay. It is a beautiful place to photograph landscapes and portraits. It's usually less crowded than the beaches to the north (Redondo Beach, Hermosa Beach and Manhattan Beach). I arrived 30 minutes before sunset and hoped for color in the clouds. Not seeing any, I decided to do a long exposure instead. I noticed the concentric circles in the sand around the lifeguard tower which reminded me of a Japanese rock garden and meditative walks.
Equipment Needed for Long Exposure Photography
You must have a steady tripod. I am a fan Manfrotto tripods, they are well made with excellent features. You can see Manfrotto's "BeFree" tripod above. The BeFree is light and strong. I have a heavier tripod for studio work but if I am out and about with a backpack, the BeFree is with me. When the BeFree is folded up it's not much bigger than a hero sandwich from a New York Deli! I keep it in my car all the time in case I need it. Tighten the legs on the tripod and be sure it is steady. Be sure the plate attached to your camera is tight. Don't extend the center column of the tripod if you can avoid it. During a 20-30 second long exposure you can't have any movement or the details in your images will be blurry.
Short test exposure. You can tell this is a long exposure because the white water by shore is getting smoother and losing details.
Typically, I will use a wide angle lens for long exposure. The wide angle works because I am usually photographing from a low vantage point, close to the ground to capture a foreground element and a big wide background. The Tamron 15-30 f/2.8 lens is a big, beefy, sharp lens that is great for long exposure. In this particular instance, I chose the Tamron 24-70 f/2.8, because my vantage point was about 50 yards from the lifeguard tower. The 15-30 would have made the tower too small. I shot the 24-70 at 33mm on a Canon 7D Mk 2 crop sensor. Thus 33 mm is 33 mm x 1.6 crop factor or about 52.8 mm. Long exposure shots are not hard once you get the basics down. I recommend shooting in manual mode for the most control.
3) Remote Trigger
To minimize camera shake and maximize details, you'll want to trigger the shot remotely so that your finger on the camera does not add camera shake. There are a number of ways to do this. Depending on your camera model, you may be able to trigger the camera shutter wirelessly, or by connecting a trigger to a port on your camera. You can also use a time delay (I often use a 2 second delay on the Canon).
4) Neutral Density Filter
The other piece of equipment you need is a neutral density filter attached to the front element of your camera. There are many ND filters out there. The cheap ND filters can leave a nasty color cast on your images. I'm a fan of Fotodiox and their WonderPana system. They make a variety of filters, but I use their 3 stop and 10 stop filters. The WonderPana system is made for ultra-wide angle lenses. You can start with the the 3 stop and move to the 10 if needed. For REALLY bright days, and/or really long exposures you can stack the 10 and the 3 together for 13 stops. The Fotodiox is the only one I am aware of that fits on Tamron's award winning 15-30 f/2.8 ultra wide angle lens, which I often use for landscapes. If you don't have an attachment for your particular lens you can carefully hold the filter in front of the camera. That's a bit risky though because you don't want to touch the lens and shake it, and you don't want too much light to leak in to the shot. Ideally, your ND filter should be made to fit your particular lens size. Check out the short video below showing the difference between the 3 stop and 10 stop Fotodiox ND filter.