The technology of photography, film or digital, has its limitations, and one of the biggest is dealing with a limited ability to capture a range of tones, compared to the infinite variety of light we actually see in nature. Ansel Adams developed his Zone System of exposure and development specifically in response to this challenge. It allowed him better control over translating real-world contrasts into the limited contrast range of film and prints.
You don't have to learn the Zone System to deal with lighting extremes today. While there are a number of possibilities available to the photographer, we've chosen three techniques that will help: filters, flash and digital processing.
Filters Still Work In A Digital Age
With the advent of digital, some photographers have begun to believe the computer can do anything, including eliminate the need for filters. Of course, the traditional photographer who never uses a computer will find some advantages to using filters, but even the digital-savvy photographer should have some filters in his or her camera bag. While the computer can do a lot, especially with the two-exposure (or more) system of tonal-range control, it has limitations. If you can control the tonality of your photo while actually photographing the subject, you'll have less work to do later in the computer. And for some scenes, it's easier to be sure you've captured the tonalities with which you need to work in one exposure than trying to make multiple photographs work together later.
The key filter every photographer should own is a graduated neutral-density filter (also called graduated ND, grads and split neutral-density or ND filters). It's a huge advantage to the photographer who wants to get the best exposure from an extreme situation.
Many of you know and use this filter, but for the beginner, here's a quick explanation. The graduated neutral-density filter is clear in one half and gray (neutral density) in the other. The two areas blend together in a gradation of tone in the middle of the filter. The filter rotates inside its mount, allowing you to move the dark, neutral-density area over the bright part of the scene. The clear half of the filter now sits over the darker part of the scene. The result is that the darker part of the scene comes through directly to the film or sensor, while the brighter part is dimmed by the ND filter. The blending in the middle hides the change. This allows you to capture a scene with a greater range of brightness than could be handled normally.
The most common way of using this filter is with landscapes. The sky is frequently much brighter than the land, making photos look unnatural compared to what we see with our eyes. With a grad, you move the ND portion over the sky so that its brightness is dimmed, allowing the sky to better balance with the ground. If your filter is of the screw-in type, you're limited to rotating the filter, which may or may not match your actual scene. With rectangular filters, you can slide them in their mount to better match the horizon.
The late Galen Rowell was a master of using the graduated ND filter in the landscape. Look at any of his photos and you'll see rich colors in both sky and ground, usually impossible to achieve with a straightforward shot of the scene. He'd even put multiple filters together to intensify their effect, moving them slightly to be sure the blended areas fit the scene.
Graduated ND filters come in a variety of strengths that affect the intensity of the effect as well. The most common are one- and two-stop neutral densities; the dark areas of the filter (the neutral-density part) will knock down the brighter parts of the scene by one or two stops. If you were to buy only one, I'd recommend the two-stop model, as it will work on more extreme conditions. The more expensive graduated filters tend to give you the most neutral density in the dark part of the filter, which can help keep your colors clean.
In addition, graduated filters also come in colors (usually in one- and two-stop strengths). These can be used to both reduce the brightness of an area and enhance the colors. For example, a blue grad can be used when the sky is a washed-out blue; it will darken and increase the color of the sky. An orange or tobacco color grad can intensify a sunrise or sunset.
Graduated filters don't have to be reserved for the sky; they can be used for any situation where the lighting contrast is high. Examples include putting the ND section over intense snow next to a pine forest, using the dark part of the filter to knock down the sun's reflections in water, or moving the ND area over the brightest part of a slot canyon. No matter how you use them, these filters help you to compose a photograph that just won't happen any other way.
How to expose? Most of the time, you can use your evaluative or matrix-type metering system and you'll get a decent exposure. Bracketing can help, and, of course, with a digital camera, you can check to be sure you got the right exposure on your LCD monitor.
Beyond that, the best thing to do is get out and experiment. This is one filter that I always keep with me, even now that I shoot mostly digital. It's so easy to use that it's worth a try in many situations where you have extreme brightness conditions.
Try Your Flash To Subdue Hard Shadows
Fill-flash does exactly what the technique's name suggests—it fills your subject's shadows with light from a flash unit. Without a fill light, shadows in high-contrast situations would record as empty black holes. In the past, fill-flash was considered a professional technique because of the complexity of the technical issues involved, but modern photographic equipment has made it simple for everyone. Your equipment will calculate exposure for two light sources, your flash and the ambient light, and arrive at settings that balance the two.
Fill-flash works well for objects within a moderate range (you might light a boulder or a small tree, but not a canyon or a mountain). More powerful, accessory flash gives more options for fill-flash. For dramatic photos, use flash at sunset to fill in the immediate foreground to balance the glowing sky.
You can start using this technique with any camera that has a built-in flash. If you're using a compact digital camera, go through your camera's flash modes until you get to the flash-on setting (the name changes, depending on camera model). The setting will cause your flash to fire even though there's plenty of light to make the photo without it. If your camera offers Scene modes, you also can try "Slow Sync" or "Night Portrait."
Some 35mm and digital SLRs also have a built-in flash. Popping up the flash tells the camera you'd like to use it, and your camera will work the flash into its exposure calculations automatically. Generally, little more is required from you when it's bright outside.
When the ambient light becomes dimmer, your camera may keep the shutter speeds in a handholdable range for some modes, which will allow the background to go dark. The fix depends on the camera; for many, you can use shutter-priority auto-exposure and set a slow shutter speed for the dimmer ambient conditions. Some cameras will keep giving proper ambient light exposures when you choose aperture-priority exposure. Slow-Sync and Night Portrait settings are sometimes available on these cameras and will often balance ambient and flash light quite well.
|Flash effects can be more subtle than the example at the top of this page. In the images above and at right, the additional illumination from a flash boosts the light.|
The big limitation of built-in flash is low power, which can be a real problem outdoors. Today's dedicated hotshoe flashes communicate with your camera, providing automatic operation like built-in flashes, yet offer considerably more strength to balance bright light. With the use of special connection cords, they also can be placed off-camera for spotlighting and other effects. Placed away from the lens-to-subject axis, their light creates texture and form that can be interesting.
You do have to consider how much flash fill you want. If the light outside is coming from behind your subject, creating a silhouette, give your flash the full normal exposure.
If sunlight is falling directly on your subject, causing small pockets of shadows, then filling in the shadows completely will ruin the three-dimensional quality of the light. Try reducing your flash's output by a stop. This dimmer fill still opens up the shadows so they don't record as empty black pockets, but preserves the character of the lighting. For more dramatic results with even less fill, try -1 1/2 or -2 stops.
Your camera's metering system may well give you nicely balanced light automatically. Experiment beforehand so you'll develop a feel for how everything works. When using digital, rely on your camera's LCD monitor to double-check that your camera's settings give you a balance of light that you like.
Keep the range of your flash in mind. The range varies according to model, but in bright sunlight, assume it's no more than five to 10 feet for most built-in flash units, with the more powerful hot-shoe-mounted strobes reaching perhaps 15 feet. For all flash units, the fill range increases as the amount of sunlight decreases (it's easier for the flash to match the lower light level), so you'll have better fill-flash range as sunset approaches.
If you shoot with a telephoto, some of the flash beam is wasted as it spreads out to cover the field of a wide-angle lens. Many hot-shoe-mounted flash units have a zoom system that extends flash range by concentrating the beam into a telephoto's narrower field. For very long telephotos, 300mm or longer, aftermarket Fresnel condensing lenses are available to fit over the front of your external flash. Project-A-Flash (www.leppphoto.com) and Flashextender (www.rue.com) will both focus your flash's light even more than your flash's zoom head and can extend flash range by more than 200%.
Some scenes, like sunsets with land or scenics with deep canyons, have a much wider contrast range than film or digital media can record. If we shoot for the highlights, we lose the shadows. If we shoot for the shadows, the highlights are gone. To get around this, use imaging software to combine two frames of the same subject, one exposed for the highlights and a second one exposed for the shadows. If the camera and subject remain perfectly still between exposures, the two images can be merged in a computer later. Either a film or digital camera will work. Here's how to do it.
When shooting the pictures:
1 Use a solid tripod so the camera doesn't move. You want the two images to line up precisely in the final photo, and if you think you might have bumped the tripod between frames, start over. It's easier to begin again than it is to realign the two images in the computer.
2 Take the first shot with an exposure that favors the highlights to lay the groundwork for the image. If a critical area of your subject is white, as with a waterfall, clouds or snow, expose to avoid blowing out your highlights. The beauty of the two-shot system is that we can underexpose this shot to maintain our highlights without having to worry about the loss of shadow detail!
3 The second shot is just for the shadows. Our aim here is to provide enough extra exposure to improve shadow detail. The "right" amount of extra exposure is an aesthetic decision as much as a technical one. While one stop often works, two or more stops also can be appropriate, depending on the scene. Bracket your exposures. That way, you'll have a range of shadow exposures from which to choose. If you're shooting digital, take advantage of your camera's LCD to check your results.
When assembling the pictures:
To create your final, long tonal-range image, use a program that supports layers, like Adobe Photoshop and Photoshop Elements, Jasc Paint Shop Pro, Deneba Canvas and others.
4 Choose the best of your highlight exposure brackets, and the image that provides the amount of detail you want in the shadow areas (look at both tonal and color information). For the latter, ignore the highlight parts of the image when making your choice. If you shot film, make a scan of both images.
5 Open your shadow image, and use the Save As command to make it the basis of a new file. Use a new name that helps you remember the image, such as "Bridalveil Falls Combined."
6 Open the highlight file. With Adobe products, click inside the image with the Move tool; drag and drop it onto the shadow file while holding down the Shift key. A copy of the highlight image forms a new layer within the shadow file, and the Shift key makes the new layer automatically line up with the original layer beneath it. With other software, you may need to copy and paste using the menus.
7 Now comes the fun part. We're going to paint in the extra shadow detail only where we want it in the highlight image. Go to the Layer menu and find the command Add Layer Mask (the exact names vary by program, but they're all similar). You'll see a second set of choices—Hide All and Reveal All. Choose Reveal All.
Use a soft-edged brush with black paint to go over the image's shadow areas (you must be in the layer mask in the Layer palette; if black or a color appears on the photo, you're not in the layer mask). As you paint, you'll see the lighter shadows from the lower image appear as the black paint hides or masks those areas of your highlight image layer. The highlight image isn't erased; the layer mask can be adjusted by painting white to bring back the layer, black to hide it again. (If the two layers don't line up as well as you'd like, see #8.)
Your photo is now at your command. You can paint in as much or as little as you like. If your software doesn't support masks, use the Eraser tool to remove parts of the highlight layer so the lightened shadow layer can show through.
The key to the technique is hiding your tracks, especially at the edges between highlight and shadow areas. Go over these edges, going back and forth with white and black paint while using a soft brush until they look right to you.
8 One last note: In spite of our best efforts, the highlight and shadow images may be slightly misaligned. This is especially true with film, as neither mounts nor scanners have precise alignment. If that happens, use the Move tool to move the top layer until it lines up with the bottom layer. Temporarily reducing the layer's opacity and zooming in will help, as will practice.
Sometimes, the two images still won't match. In that case, line them up the best you can, and make judicious use of the Cloning tool to fix bad gaps.