Spectacular Sunsets: Low-Light Photography for Yachties

7 January 2009 By Miles Bisset

Yachties all have one thing in common, and that is our affinity to take loads of photos from all the spectacular places we venture. All you need is a decent digital camera and a little know-how to capture memorable shots.

One thing that seems to catch us out regularly is taking good images in low-light conditions, such as when the sun is setting or rising. You can try setting your camera on “auto” and hope the flash doesn’t overexpose parts of the image. But a flash is useless when trying to capture that amazing sunset at sea or sunrise over St. Barths.

Once you understand the basics of how your digital camera works (or for those who still use film), you’ll be able to capture very rewarding low-light pictures with minimal effort. To get started, all that’s required is a digital camera with a “manual” mode that enables you to change the aperture and shutter settings yourself. It doesn’t necessarily need to be a DSLR (digital single-lens reflex) camera, as most “point-and-shoot” cameras these days have this mode, normally indicated by an (M). The partial automatic settings for aperture (AV) and shutter (TV) priority also allow you to adjust either the aperture (also called F-stop) or shutter speed independently.

Photography relies primarily on light. If you understand that basic concept, you're already 80 percent on your way to creating fantastic images. In digital cameras, light passes through the camera lens onto a semiconductor, which records the light electronically and converts it into a digital format that the camera processes, displaying the image on the LCD screen on the back.

The auto setting is usually a good choice if light is plentiful or composition of your photo is simple. But when light is low, or you want to bypass auto settings and get more creative, a camera set on “auto” may limit you. The solution is to change to the M, AV or TV modes and start playing with the settings.

The shutter, aperture and ISO are the three settings we will focus on here. The ISO relates to the sensitivity of the image. A lower ISO setting (i.e.: 100) will create an image that is less light-sensitive but with a higher pixel quality. The higher the ISO setting (i.e.: 1600), the more light-sensitive the end result will be; however, the pixel quality will be lower. It's a fine line you will need to experiment with.

The shutter does exactly as its name describes – opens and closes, allowing light to pass onto the semiconductor. When there is very little light, the shutter needs to stay open for a longer period. The higher the shutter speed (i.e.: 1600 ), the faster the shutter will open and close. The lower the shutter speed (i.e.: 20), the longer the shutter stays open admitting more light.

The aperture acts in a very similar way to the iris in a human eye. It controls the effective diameter of the camera’s lens opening.

Another very important aspect to remember is that the longer the shutter is open, the more sensitive the camera will be to “camera shake.” Ideally, you should be on land or docked in a location where the boat is not rocking. Use a tripod (you can find compact, telescoping models that are easy to carry and store), or brace the camera on a railing, the back of a chair or in some other stable location offering a clear view of the subject matter. Another neat little trick you can try is to use your forced flash setting on manual with a slow shutter speed. The initial light from the flash will assist to light up the image.

When taking sunset photos, until the sun actually disappears there often is enough light to use faster shutter speeds and higher aperture settings (F11, F16, etc). These photos usually can be shot hand-held or by bracing yourself against an object for added stability.

The best advice, once you understand the basics of how the aperture, ISO and shutter speed of your camera work, is to play, play and play some more. “Bracket” your photos by testing various shutter and aperture settings. The beauty of a digital camera is that you see immediate results, so you’ll know right away whether your method works or not. The “delete” button is a photographer’s best friend!

The final ingredient in shooting a great low-light photo is composition. For sunrise and sunset photos, make your images more intriguing by introducing interesting elements. Using a telephoto lens, try to capture a bird flying across the sun or another boat moving along the horizon. You also can frame a sunrise/sunset shot with palm trees or other available objects to make the picture more captivating.

Longer shutter speeds also offer interesting opportunities to take time-lapse photos of cars, people or boats in motion moving past you. For longer shots of 15 seconds or more, try flashing the image with a hand-held flash near the end of the exposure for a shot showing the object moving and static at the same time.