Why Long Exposure Photography Is So Much Fun, but So Hard to Get Right

The first time I saw streaky clouds and silky smooth water, I knew I needed to learn how to do that. However, after buying my first neutral density filter, I realized it wasn't so easy to do. It was really hard to focus, and some photos were too dark, while others were too bright. And why were the middle of so many photos pink? Hopefully, this article will help you avoid some of the mistakes that I made as a long exposure beginner.

While I am not a particularly patient person, I learned quickly that long exposure photography takes a lot of patience, and that's not simply because exposures routinely reach three or four minutes (they can go much longer than that too). It's because most long exposure pictures, especially as a beginner, suck. Embrace trial and error and remind yourself that you're probably not going to get it right on your first or second try.  While there are cards that will help you estimate how long an exposure should be based on the exposure length without a neutral density filter, those estimates cannot account for the many variables that often exist in long exposure work, such as moving clouds, water, light trails, or even just the dynamic range of the photo.  

When I arrive at a location, I usually have a pretty good idea of what I want to capture. If there is water, I want it silky smooth; if there are clouds, I want them streaky; and if there are cars, I want light trails. After I set up my tripod, I compose and focus my image before I put any filters on my camera. I use a Sony a7R II and the Lee Filter System (I have a Big Stopper, a Little Stopper, and a bunch of graduated ND filters from Lee). Based on my experience, mirrorless cameras are much easier for shooting long exposures because they give you a real time preview of your shot on the LCD screen or the EVF, so you end up wasting fewer shots trying to get the exposure right.  Once I have my composition and my camera is focused, I will add my filter or filters (depending on whether the sky needs a a graduated filter on top of the ND filter because of the large dynamic range).

Finally, I start shooting. To pick my initial exposure, I will usually put the camera in aperture priority mode, setting my aperture somewhere between f/8 and f/11 and letting the camera select the correct exposure. Although the camera will often get this wrong, it usually gets me close enough to start my trial and error process.  After my first shot, I switch to manual mode and fine-tune the exposure. This will often require exposures that exceed 30 seconds, meaning that the camera must be in bulb mode. Bulb mode allows the photographer to choose the exposure value and allows you to expose for as long as you want. To use bulb mode effectively, you will need a shutter release cable or an infrared remote (I prefer a shutter release cable). From there, I keep shooting until I like the results, which often takes many shots. However, I always zoom in on the back of the camera to inspect the shot before moving on. Sometimes, what looks good on the LCD screen may not look so good when zoomed in close: the shot may be blurry, out of focus, or contain blown out sections. When I am back home, I process my images in Lightroom and Photoshop with Nik and Macphun plugins. 

General Tips for Beginners:

• Expose for the highlights; you can recover the shadows in post, but if you blow something out (usually the sky), it's unlikely you will be able to recover it. Also consider taking multiple exposures, one for the highlights and another for the shadows, and then blend them together in Photoshop.
• Be careful of light leaks. A light leak is when light leaks into your long exposure through the viewfinder and creates a discolored (usually pink) band across the middle of the photo. This is very common with DSLRs (it doesn't happen too often with mirrorless cameras). To avoid light leaks, cover the viewfinder during the exposure. Some DSLRs come with a piece that covers the viewfinder, but if you don't have it with you, you can use tape or anything dark that will block out the light. 
• Many neutral density filters will create a color cast and leave your image cooler (bluer) than expected. While I usually fix the white balance during post, you can also set a warm custom white balance before you take your shot to offset the color cast in camera.  
• Keep your ISO as low as possible. Long exposures can get really noisy, and the lower the ISO, the less noise there will be. 
• Use a shutter release cable to avoid camera shake. It will also allow you to operate effectively in bulb mode to get exposures lasting more than 30 seconds.