Understanding Exposure (3rd Edition): An Update On A Classic Best Seller

The following is an excerpt from Bryan Peterson’s Understanding Exposure, 3rd Edition/Revised And Updated: How to Shoot Great Photographs with Any Camera (Amphoto Books, $25.99, August, 2010). The revised edition (ISBN: 978-0-8174-3939-2) brings this best seller up-to-date for the rapidly changing world of digital photography and brings readers information on how to learn the difference between a correct exposure and a creatively correct exposure. This new edition includes updated information on advances in digital photography, such as increasingly sensitive ISOs and HDR (High Dynamic Range) photography, an expanded discussion of white balance, tips on using flash, and many new images. The section we are featuring with images and captions (there’s even more information in the accompanying text) is on night and low-light photography. This is one book that’s easy to recommend.—Editor

All Photos © Bryan Peterson

One of the many suspension bridges in Lyon, France, has two large, deep red metal struts, one at each end. On the east end, you can look to the west and frame the Fouvrier atop Old Lyon through the struts. I’ve seen countless tourists make this shot throughout the day, but I have yet to see anyone do it at dusk, which you’d have to agree makes for a better shot.

With my camera on tripod, I set my aperture to f/22, and with the lens pointed to the dusky blue sky, I adjusted my shutter speed until 3 seconds indicated a correct exposure. I then recomposed the scene you see here, and with the camera’s self-timer set, I pressed the shutter release. The reason I use the self-timer with “long” exposures is simply to avoid any contact with the camera during the exposure time. I don’t want the risk of any camera shake, since sharpness is paramount most every time I record an exposure.

Note that your camera’s default for the self-timer is usually a ten-second delay, but I would strongly recommend that you consider changing this to a two-second delay. Waiting ten seconds in between shots can often mean not getting the shot. (And to be clear, you can also use a cable release, but even here there’s the slight risk of camera shake, since you’re still “tied” to the camera.)
35-70mm lens, f/22 for 3 seconds

“Paint the Town Red” was the campaign for the city of Sydney during my two-week stay there years ago. Even the opera house was covered in red light. Not one to waste an opportunity, I set up my tripod. With my aperture set to f/8, I tilted the camera up to the dusky blue, cloudy sky and adjusted my shutter speed until the meter indicated 2 seconds as a correct exposure. I then recomposed and made several exposures, tripping the shutter with the camera’s self-timer.
80-200mm lens, f/8 for 2 seconds

The Aravais Mountain range in the northern French Alps is a skier’s paradise, and the village of Grand Bornhand sits in the valley floor of these impressive mountains. It’s a town that offers wonderful low-light photo opportunities if you can put off eating dinner for half an hour or so!

With my camera and 35-70mm lens on a tripod, I set the focal length to 35mm and the aperture to f/2.8, and then raised the camera to the dusky blue sky above the mountain range. I adjusted the shutter speed until the meter indicated 1⁄8 sec. as a correct exposure. I then recomposed, stopped the lens down 5 stops to f/16, and increased my exposure time by 5 stops. With my exposure time now set for f/16 for 4 seconds, I tripped the shutter with my camera’s self-timer.
35-70mm lens at 35mm, f/16 for 4 seconds

With the fall of communism, tourism to many of the former countries who were locked behind the Iron Curtain increased. Perhaps none has been more visited by travelers the world over than Prague, Czech Republic. It is truly a beautiful city! Your first challenge, however, won’t be recording a correct exposure but rather jockeying for a position on the concrete path that hugs the Danube River. When I made this shot, the tour buses had emptied out and the shooters were out in force, just as determined as I to record a great shot of Prague and her illuminated castles. Unfortunately, most of them didn’t get the shot. Without a tripod, a night shot of Prague is just not going to happen.

With my camera on tripod, I first set my aperture to the “Who cares?” choice of f/11 (since everything was at the same focused distance: infinity). I then tilted the camera to the dusky blue sky and adjusted my shutter speed until 4 seconds indicated a correct exposure. After that, it was simply a matter of recomposing the scene, and with the aid of an electronic cable release and the camera set to mirror lock-up, I fired off several frames, one of which also recorded the slow movement of a tour boat that had entered the frame.
17-55mm lens at 32mm, f/11 for 4 seconds

When I made this long exposure of St. Peter’s basilica in Rome, I started shooting shortly after the streetlights had come on, yet the church itself never lit up! In any event, I used a filter I can’t live without (besides the polarizer and Tiffen 3-stop graduated): the FLW. It’s a magenta-colored filter not to be confused with the FLD. The magenta color of the FLW is far denser and is far more effective on normally greenish city lights, giving them a much warmer cast. Additionally, this filter imparts its magenta hue onto the sky, which is perfect for those nights when there isn’t a strong dusky blue sky.

With my camera mounted on a tripod, I at first set my aperture to f/4. I pointed the camera to the gray sky and adjusted my shutter speed to 1⁄2 sec., but since I had already determined that I wanted the longest possible exposure time, I did the math and ended up at f/32 for 30 seconds!
105mm lens, f/32 for 30 seconds

While many photographers watch the moon rise, few photograph it because they aren’t sure how to meter the scene. Surprisingly, however, a “moonrise” is easy to expose. It’s actually just a frontlit scene—just like the frontlit scenes found in daylight—but now, of course, it’s a low-light frontlit scene.

Since depth of field was not a concern here, I set the aperture on my lens to f/8, metered the sky above the tree, adjusted my shutter speed to 1⁄8 sec., recomposed the scene, and—using the camera’s self-timer—fired the shutter release button.

Note: In this instance, as well as for other full-moon landscapes, it’s best to take the photograph on the day before the calendar indicates a full moon. Why? Because the day before a full moon (when the moon is almost full), the eastern sky and the landscape below are darn near at the same exposure value. (And, truth be told, I could have also taken my meter reading from the wheat field in this scene and it would have been within a cat’s whisker of the meter reading for the sky.)
300mm lens, f/8 for 1⁄8 sec.

A firm and steady tripod enabled me to shoot this classic scene of the San Francisco skyline. With my camera and 35-70mm lens on a tripod, I set the focal length to 50mm and set my aperture wide open at f/2.8. I then pointed the camera to the sky above and adjusted the shutter speed to 1⁄2 sec. Since I wanted an exposure of at least 8 seconds to capture the flow of traffic on the bridge, I knew that by stopping the lens down 4 stops to f/11 would require me to increase my exposure time by these same 4 stops to 8 seconds. With an 8-second exposure, I tripped the shutter with my cable release.
35-70mm lens at 50mm, f/11 for 8 seconds

Author Bio
Bryan Peterson is a phenomenon in how-to photography, with more than half a million books sold. A professional photographer and internationally known instructor, he is the author of Understanding Exposure, Learning to See Creatively, Understanding Digital Photography, Beyond Portraiture, Understanding Shutter Speed, Understanding Close-Up Photography, and Bryan Peterson’s Understanding Photography Field Guide. Peterson’s forthcoming book, Understanding Flash, will be available in August. He is also the founder of the online photography school The Perfect Picture School of Photography (www.ppsop.com).

Understanding Exposure, 3rd Edition, by Bryan Peterson (ISBN: 978-0-8174-3939-2) is available in e-book format, online and wherever photographic books are sold.