Lighting Observations, Lighting Terms

 Lighting Observations, Lighting Terms

There are commonly used terms that describe lighting conditions and how they relate to both photographic "seeing" and camera technique. The aim here is not to categorize the miraculous, but to suggest ways in which you can capture the subtlety and nuance of light in a wide variety of conditions. 

There are some terms that will be abbreviated throughout this entry: WB=white balance settings on your camera. ISO=Light sensitivity settings. CWA=center-weighted averaging metering pattern setting. Biasing refers to the area of brightness that should be taken into most consideration when making light readings. Bracketing refers to adding +/- exposure to the read light.

In photography, light is often defined by its source

Natural Light: Primarily from the sun. The intensity, color temperature and contrast is infinitely variable, as are the influences of reflection, transmission, and diffusion: all can change the perspective and mood within the scene.

The middle afternoon sky was clear, thus no influence of the color cast of light is evident. An exposure reading was made from the upper right corner of the frame and then locked for this composition. Copyright: George Schaub 

Ambient Light: Also referred to as "available" light", this term generally applies to low light scenes that usually require a higher ISO setting and/or slow shutter speed (depending on widest lens aperture). 

Here, this store display was photographed at night through the display window using the interior lighting as the sole source. The circular lens shade was placed very gently against the pane to eliminate reflections and help steady the camera. ISO was set at 800 to capture a wide range of illumination.

Copyright: George Schaub

Artificial Light: Illumination provided by filament or fluorescent bulbs, strobe (flash) or any other battery or mains powered lights. On-camera flash generally provide automatic output, though testing is encouraged. WB should be set on Auto, although for more refined results consider a "custom" white balance tailored to the light source (see your instruction book for more). For pro or studio strobe a handheld light meter comes in very handy. 

Auto white balance setting held record a "natural" look of the lights of New York's Times Square. ISO was set at 800 as the widest aperture on this fisheye lens was f/5.6. Copyright: George Schaub

Light is also defined by its character, where mood and sense of time and place are defined.

Hard Light: Hard light creates high contrast and deep shadows. While challenging in some ways it is an exciting light to work in, given you know how to control contrast. It can be directional, meaning it comes to the scene from an oblique angle. It can also be ambient, especially at high altitudes or when the sun shines brightly on a snow covered landscape. Knowing what information to "feed" the metering system is important, as biasing the exposure toward the highlight means rich values with less danger of overexposure. Exposure bracketing is good practice, with spot or CWA on the brighter area. 

There is a lot of graphic potential within "hard light" scenes, especially when the reading is specific to the highlight area. Here, a spot reading was locked on the yellow hull in the background. Note how the red brace in the foreground stands out as  counterpoint within the frame. Copyright: George Schaub

Soft Light: Often diffused by fog or overcast sky, soft light can be surprisingly color rich as the medium through which it light passes makes for a soft, ethereal glow on select subjects or the overall scene. Contrast is low, so experiment with exposure bracketing, plus and minus, to add to the effect.

The "afterglow" effect occurs for about 20 minutes after the sun sets below the horizon and provides a wonderful soft light for any subject or scene. Often thought of as primarily an effect for nature scenes it also works well for city skylines. These scene was bracketing -1EV. Copyright: George Schaub

Warm Light: Warm light generally refers to a color cast in the yellow/amber side of the spectrum. It can emanate from the low angled setting sun or even from a tungsten bulb in a room. While the instinct or even the right choice  may be to switch to Auto WB to eliminate the cast, photographing warm light scenes using the Daylight WB settings maintains the perceived light in the scene.

Daylight WB setting maintains the warmth of the setting sun on these redwoods; using Auto may have "balanced" the cast but for me would have sacrificed the mood. Warm balance images tell the viewer about not only the subject but the time of day in which the picture was made. Copyright: George Schaub

Mixed Light: Choosing Auto or Daylight WB, or even setting a Custom WB, can have a major affect on scene rendition. Auto will tend to find a solution that may or may not appeal; warm will create the above-mentioned amber cast, while a Custom WB, will allow for a wide range of rendition options.

Here's an example of mixed color casts, warm and cool (or bluish). The setting sun was sending golden rays flat across the horizon while an approaching mountain storm (untouched by the rays of the sun) recorded in the blue range. Both recorded correctly as the way I saw the scene at the time. When I want to record color casts as I saw them I use Daylight, not Auto, WB. Copyright: George Schaub

Light's Direction: Light can also be defined and exposed according to the direction from which it originates and, of course, the point of view of the photographer. 

Backlight: This is when subjects fall within their own shadow. You can also use backlight to create a bright background for an object or subject, then use flash to illuminate the foreground. 

Taken at sunset with the lighthouse between my camera and the sun, a perfect silhouette is formed, with the lantern passing the light between its structural ribs. Copyright: George Schaub

Side Lighting: Side light occurs when you place yourself at somewhere between a 90 and 45 degree angle from the light source. Sidelight can occur right after dawn or near dusk when the light travels across the surface of the earth. When exposing, concentrate on the brighter areas using CWA or even spot metering pattern and if the light's challenging don't hesitate to bracket.

Side lighting presents both challenges and great rewards when done right. Here I made two exposures, one using CWA metering and the other spot reading, and then exposure lock after each reading. One exposure (CWA) incorporated the sky but included some of the ground, while the other (spot) reading was made off the golden light on the field. The CWA image worked best, as it averaged out the brighter sky area and created nice shadows. The spot reading was great for the field and barns, but overexposed the sky somewhat. Remember, with digital you have to control the highlights, as you can "dig" into the shadows during processing later. Copyright: George Schaub 

 

Backlight: Exposure, Options and Techniques

The sun was striking these still-green leaves on a bough backed by brilliant color and stark trunks. The difference between the bough and background was about 1.5EV, but reading right off the bough made the colors in the background to go darker, which created a strong play of brightness and color.

As the term implies, backlight is a strong light behind your subject as it faces the camera. In some cases it can cause exposure problems, but it is also one of the most beautiful light sources for translucent subjects. Think of stained glass windows in a church. They are rather dark and dull when the sky is overcast, but when the light comes through them they are the most glorious window treatments of all.

Backlight is inherently contrasty, meaning that there will be a considerable difference in exposure between parts of the subject and the light behind it. In some instances this means that parts of your subject will either sit in silhouette (having form but no detail within the form) or be considerably underexposed. The key to backlighting is to exploit this contrast, to use the shadows it “throws” toward the camera as part of the composition. You do this by biasing exposure toward the brighter light. The usual solution to getting detail in a subject that is backlit is to use flash to “fill” the foreground subject with light, but that defeats the purpose and dramatic potential of this kind of lighting.

Tools and techniques: spot metering mode, exposure compensation, autoexposure lock.

The bright light here is supplemented by reflections off the pond, which provides a natural fill light for the darker parts of the scene. Nonetheless a spot meter reading of f/16 at 1/250 second at ISO 200 was made directly off the bright yellow leaves on the left side of the frame.

Perhaps the most colorful season in which to exploit backlighting is fall, when brilliant color displays combine with low angle light. The key to exposing this type of lighting is to avoid bringing shadow areas into consideration and read from the backlit leaves themselves. This is easily done by using spot metering mode and locking exposure on the brilliant light of the leaves. In most cases this will be the proper exposure, but in some instances you might want to use a + exposure compensation to add some brightness to other parts of the scene. This rarely goes above +0.5EV. Once you attain the exposure and review it to make sure it does the job, lock it, or switch to manual mode to maintain the exposure as you work in the area.

If you are shooting in the shade with a bright sky behind the main subject you can either crop out the sky and not worry about contrast, or expose for the main subject and deal with the bright backlight later in processing. These formations sat in deep shade but I wanted the sky for relief of the forms at the top of the frame. I used CWA to make the exposure, locking it on the formation itself, then recomposed. Later in post I selected the sky, which was blank in the recording, and added a very light blue color wash.

There may be times when working with backlight that the sun is higher in the sky and/or cannot be absorbed by a dense background.  It is essential to then make sure you block the sun from both the image and from exposure consideration. I often do this by finding a shadow area cast by the foreground subject and stand within it to make the picture, or at least position myself so that I block the sun with a branch, rock or other obstruction. Failure to do this will result in flare and an exposure that is thrown off by the strong presence of a direct light source. In addition, it is never a good idea to look through the finder directly at the sun. In this shots I used a branch to black the sun and took my spot reading from the leaves of the center tree.