The lighting technique must be a tool totally under the control of the photographer, so it turns into a creative resource, not into a wall to our creativity.
To light a model's face is the first challenge for lots of photographers, specially those shooting fashion and portrait photography. A badly lighted face can be the key for a failed photo, and most of the times it's something that we do not pay the attention it deserves.
As human beings, we observe the human body with a lot of attention: There are lots of guidelines in the pose, the expression and the silhouette of a human body, all of them gives the observer an enormous amount of information. To overlook this is a warranty of a failed photo, or at least, of a photo different to that we were searching for.
Specifically in the face is where almost all the visual guidelines reside. Of course, we're not only talking about the physical features of the model, but also about its expression, its attitude, three-dimensional volumes and its morphological proportions. All this information can be yield to our control: Applying lighting techniques in a smart way, we can work consciously the volumes, the lines, the textures or the lightness-darkness contrasts, and mold most of the factors that will modify the final expression of a face.
In the following examples we'll gradually analyse some common failures when lighting a face, and we'll take a look at how we can mold a face with the light, or with the absence of light.
Although there are lots of possible lighting schemes and combinations for a face, in the following examples we'll focus on a lighting scheme which is, probably, the most used one, and it's also very easy to accomplish with just a bit control:
Totally frontal lighting
The one we will get when using the camera's integrated flash, an external flash in the top of the camera, or a natural source of light completely frontal.
It eliminates almost all the shadows that will mold the volumes in the face.
Since this kind of lighting is almost always very harsh, there will be frontal shinnings which are normally not so photogenic, specially if the model's skin is greasy, or if there are some sweat.
The use of a ringflash will give us this kind of lighting, with the condition of a more diffused light.
It's the more comfortable lighting we can get, since there's no need to take care of the camera position, nor the model's head direction: The shadows will always vanish. And this doesn't have to be a good point in all cases.
Frontal elevated lighting
Shadows under the eyebrows, the nose and the neck will appear. Also, when the model's face have volume on its cheekbones, shadows under them will also appear.
The line below the cheekbones is commonly associated to slimness, and stylizes the face's silhouette.
The shadows under the cheekbones are a resource commonly used by make-up artists: They can add or vanish them at his own will.
The shadow of the face in the neck gives three-dimensionality to the face, putting it in a different plane, closer to the camera.
The shadows under the eyebrows increase its expression, and reinforces the eye-shadow make-up technique.
The shadows create a symmetrical structure in the face, which can be an interesting creative resource.
Lateral centered lighting
The symmetry in the face disappears.
A half portion of the face is vanished in shadows. If the background behind the face is also dark, we'll lose the perception of the face's real width. This is a common trick to make a face look slimmer.
Since the light is positioned at the face's same level, small light and shadow blocks will appear in the opposite cheek in a random way. Those small blocks are not normally considered photogenic, because they create a complex structure which is most of the times unnecessary.
If we increase the angle of the light pointing to the face, turning it in a more lateral light, the opposite eye will vanish gradually into a shadow, until a big shadow block will appear, covering the complete half of the face.
Specially with harsh light, or with the light of a day without clouds, the shadow cast in the nose will be very long and prominent.
Elevated lateral lighting
We keep all the good points of the previous lighting, and the bad one are removed.
The perception of the real face width is still unveiled.
A line is created under the opposite cheek, which emphasizes the silhouette and the prominence of the cheekbone.
The small blocks of light and shadow disappear.
A simple light and shadow structure appears in the opposite side of the face. We are very used to see this kind of light structures in the real life, and it gives the observer a lot of information about the face structure.
An inverted triangle structure appears below the opposite eye, which we can adjust at our will by varying the angle of the light, keeping the bottom vertex of the triangle open to the rest of the light structure, or closing it to form a complete inverted triangle.
This is, probably, the most commonly used start point when creating a face lighting, when we want to get benefit of the expressiveness in the light and shadow structure of a face.
Starting with the last lighting scheme, we add a second source of light with the purpose of softening the shadows.
We obtain detail in the shadows cast by the main light, but maintaining its structure.
We've almost lost the effect given by the loss of the perception of the face's real width when having a dark background.
The intensity of this fill light will depend on the final effect we want to obtain. As a general rule, we can start experimenting with an intensity of two f-stops under the main light.
We must take care of the angle of this secondary fill light, so it doesn't adds intensity to the zones already lighted by the main source.
This corresponds many times in the light we can normally observe in the real life.
Starting with the aforementioned elevated lateral lighting, we add a backlight in the opposite side of the main light.
We are defining the silhouette behind the shadows of the main light, emphasizing the real width of the face.
Often used to remark the jaw's prominence. This can be used to indicate masculinity and roughness, and sometimes to emphasize a stylized jaw's silhouette, when the model allows it.
Many times a line of light will appear below the cheekbone, maximizing even more the aforementioned effect.
A strong three-dimensional effect is created, thanks to the definition given by all the lightness-darkness contrasts.
The backlight effect will disappear if the model's hair catches the light before the face does.
In models with curly hair, or very spare, numerous small light and shadow structures out of our control will appear in the cheek.
We can adjust the width of the light line by varying the angle of the light.
The more we put this source of light behind the model, the more flares and unexpected light effects we will get in the photo. We can control them by using a shader in the lens, in the source of light, or any other similar accessory.
Depending on the final effect we intend to get, a different light intensity can be applied to the backlight. A good starting point is to set this light one f-stop above the main light.
We can adjust the range of the effect by elevating or lowering the light.
We can use the backlighting also in the hair: If it is straight and shinny, a simmilar light line will appear. If it is dry and backcombed, the hair will appear as it is lighted from inside. In both cases, the effect will be even more noticeable with blonde hairs.
Putting together the three aforementioned light elements
Elevated lateral lighting.
Circular background light
Specially with a black background, this effect light will show the silhouette of the entire face.
Will virtually put the face or the entire model in a different three-dimensional plane further from the background.
Will direct the attention of the observer to the circle of light.
On a black background, changing this light's color is as simple as putting a color filter in the source of light. In a white or lighted background, the color effect will be more difficult to reach and it will become sometimes out of control and unpredictable.
Gradient background light
As with the previous light effect, but intending to create a gradual tonal range from one point of the background to another.
We can adjust the gradient intensity and its range by bringing the light closer the background.
lots of times, we will get unwanted light in the model reflected from the background or coming from this background effect light. This is why sometimes this light can be used at the same time to get a backlight into the model.[