Low key or high key lighting ?
Great portraits can be created by both high key and low key lighting. One isn’t better than the other.
while high key lighting tends to be more contemporary, Low key lighting tends to have a classy feel to it. The key as in any other photograph, with either is to shoot a portrait so that the face is the part the viewer looks at first. How can that be achieved ? When the outfit and the background are similar, the face becomes the different part and therefore the viewer’s eye will go to the face, which is exactly what desired in a portrait. The subject's outfit and the background don’t have to match exactly, but they should be more or less the same brightness or tonality.
The choice of adopting High or Low key lighting also arises inherently in terms of what the subject is wearing.
If the subject is wearing dark clothing (preferably solid deep colors), then opt for a dark background and low key lighting. The background can be a solid color (seamless paper), a painted canvas background (with a bit of light on it). Even a white wall if it is quite a distance away from the subject, receiving little or no light falling on it will photograph dark grey or black. Low key portraits also tend to have less or even no fill light to take advantage of the play of light and shadow. Hard directional light also adds darker shadows making it more dramatic and Low key. The idea is to let the darker tones dominate the photograph.
If the subject is wearing white or pastel coloured clothes (again preferably a solid colours), then opt for a white or lighter background along with high key lighting. This can be white seamless or a white wall. Black seamless with lots of light falling on it may not work as effectively as a white background worked in the absence of light falling on it. High key portraits tend to use flat soft diffused lighting when compared with low key portraits, Low key photographs have less shadows and more highlights.
The use of similar density clothing and background and the amount of shadowing determine whether a photograph is deemed to be low or high key. These are not hard-and-fast rules but rather guidelines. It’s certainly possible to get lovely portraits and not follow these suggestions, but these guide- lines are a good place to start.
Low key portraits can be quite dramatic. To a large extent, it depends on how much fill we use. Shadows define the face shape and mostly directional hard light is used. There are no white boards or reflectors. Although this style does accentuate wrinkles and other flaws on the face sometimes they are part of the subject’s characteristic. How much you accentuate them is determined by placement of the main light and how much fill you use. Because the clothes and the background are dark, the viewer’s eye is drawn to the brighter area, that is, the face. By using very little fill light, a compelling low key portrait can be created. Such photographs also have deep saturated colours if the subjects outfits or the background are ot absolutely dark or black. Adding more fill light would fill the shadows that in this case are desirable to keep the tomes deep and dark.
Generally we want to place the main light so it skims across the face and ends at the near cheekbone. The placement will vary from person to person based on the subject’s bone structure. We also want it at a height so we get a good catchlight in the eyes. If the light is too high and there is no catchlight, the person tends to look lifeless—not generally a goal in portraiture.
High key portraits tend to use more even lighting than low key. The effect is meant to be light and airy. They use a white or light-colored background (often seamless paper or muslin or a white wall or sheet). The sitter wears white or pastel coloured
clothing. Again, this will draw the viewer to the different part of the image, namely, the face.
In the following three photos, we show how to transition from hard lighting to the softer lighting we want for high key images.
For high key images, we almost always use a background light in order to keep that background truly white. Without the back- ground light, we would have
to keep the background really close to the subject in order to keep the background truly white, but this increases the likelihood of shadows falling on the background. By raising our lights, we can often make the shadow disappear behind the subject, but this entails having all of our lights be off the camera. Because in this series of photos we are working with the built-in flash, which cannot be repositioned, we either have to use a background light or settle for a grey background.
When shooting images that encompass more than just head and shoulders, we will often need more than one background light if we want more of the background to stay evenly lit. Frequently, we can’t put a light directly behind the subject, but we would rather position one or two lights on each side of the background and meter the lights so we get even illumination across the background. A general rule of thumb is to have one to one-and-a-half stops more light on the background than on the subject. Depending on the placement of these lights, sometimes we will need to use gobos or barn doors to prevent the illumination from these background lights from also lighting our subject, which we don’t want.