Science of Lighting

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Science of Lighting

December 01, 2015 - 14:54

Light is the most important thing for all photographers. It is easy to get excited about a critter and start firing away without much consideration for lighting. However, it is the little extra things that you juggle beyond pointing your camera and clicking the shutter that makes your style unique.

High key versus low key exposure

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When it comes to the discovery of photography, every individual’s story is unique. It pulls every person in with a slightly different appeal. In the case of land photographers, the many styles will attract all walks of life. Landscape photography may be tailored to a photographer fonder of solitude and adventure whereas portraiture could be geared towards a socialite whose charisma may evoke the right moments from their subjects in front of the camera. There is a vast range of genres.

Underwater photographers share a special appreciation for marine life. Often, that is the reason most of them pick up a camera: to begin capturing unique sightings and experiences. The focus of the underwater photographer is to get a nice clean shot in a finite moment of opportunity—simple enough.

Nevertheless, time and time again, common errors arise with underwater photography enthusiasts. With so much additional obligations underwater, it is easy to shift focus to buoyancy, depth, No-Decompression-Limits (NDLs), currents, temperature and so on.

What about the most important thing in all types of photography? It is light, of course. Underwater photographers often take less notice of it because of the sheer number of distractions inherent in the act of scuba diving.

As a photographer, light needs to be the primary focus. Without knowing how to utilize it to its full potential, one begins to use repetitive lighting techniques for no reason other than because “that subject needed more color and light.”

Are the shadows meant to be pure black? Or was that an accident? Was the sun meant to make the whole top of the image pure white? Or is that to be darkened in Photoshop?

For photographers who are looking to excel, I recommend that they do as much of the work in-camera as possible. Correcting exposure in post-production software can degrade the quality of the image.

Strobe techniques

When using strobes in the water, it is important to remember what the three camera settings affect. A low ISO is a best friend in keeping a high dynamic range. The dynamic range is the camera’s ability to capture details in the darkest and brightest areas of the exposure. Light below the surface falls off abruptly but it is important to retain as much information in the exposure as possible.

When shooting wide-angle, it is common to have an issue with the surface looking too bright or even going pure white in the image. It is best to avoid exposures with pure whites or pure blacks unless there is a specific aim.

The relationship of aperture to shutter is vital in helping understand strobe techniques. The aperture will control both the exposure of natural light and the strobe, whereas the shutter speed will only control the exposure of natural light. How bright the natural light is in relation to the strobe light will determine the ratios of the exposure.

Expression and mood

Lighting can be an expressive language. A variety of moods can be achieved based on the characteristics of a light source. The language is practical in theory, but as always, putting theory to action tends to be more difficult. Like with all languages, the more one practices, the more fluent one becomes. This is a great way to diversify a portfolio because skillfulness will always produce better images than expensive gear.

So what kind of mood should the image have? All lighting is broken down into two categories: high key and low key. High key refers to bright exposures that complement cheerful or light moments. Low key refers to exposures that utilize more shadows and tend to be more dark and moody images. In real life, nothing is black and white, and thus, there are ways to control the degree to which the photograph is high key or low key.

Five characteristics

There are five characteristics of a light source that affect the feeling of an image: intensity, quality, distance, angle and color. All of them push a photo in the direction of being a little more high key or low key.

Intensity. Firstly, intensity plays a major role. It is fundamental in getting the desired exposure and accurate colors. Whether the goal is balancing the lighting to be equal to that of the sun above, or to blacken everything in the background entirely, there will always be a need to adjust the power of the light source in order to attain optimal exposure.

Quality. The quality of light determines how hard or soft the light is. Hard light gives hard and defined shadows that complement a more dramatic and edgy look. Soft light has very soft shadows that do not have defined lines but rather transition by a gradient. Soft light is suitable for gentle moments. This is strictly controlled by the size of the light source.

The larger the light source in relation to the subject, the softer the light becomes. So a strobe would be soft light when used up close on a hairy shrimp that is a mere speck in comparison but a hard light to a giant grouper that is larger than the light source itself.

Distance. The distance of the light source from the subject works hand in hand with both quality and intensity. The farther away the light source is, the smaller it becomes in relation to the subject, thus creating a side effect of hard light.

Of course, the intensity of the light is affected by how far it must travel; the farther it travels the more power is lost. This is exponentially important underwater where the density of water absorbs light at a profound rate.

There is another important reason to consider distance—a principle based on the inverse square law that states: double the distance, half the power. So a subject positioned one meter (3.2 feet) away from the light source is half as intense as it could be when positioned half a meter (1.6 feet) away and only half of that when positioned at a quarter of a meter (0.8 feet) away and so on.

When observed, the change in intensity of light becomes more gradual as the subject is placed farther from the light source. So if a photographer wanted to light a large scene evenly, it would be prudent to put the light source farther away (and turn up the power to compensate for lost intensity). If it is a bright and sunny background that needs to be underexposed, the strobes should be brought as close as possible in order to take full advantage of the strobe’s maximum intensity. It is up to the photographer to decide what is the priority for their image.

Angle. Another important characteristic is the angle at which the light source is positioned. Shadows are important for creating a sense of depth in a two-dimensional image. As the angle of the light, away from the lens, increases, the more apparent the shadows become. The more shadows there are, the more dramatic the lighting begins to look. This is why on-camera flashes tend to make images look flat: the light source is at the same angle as the lens, reducing the amount of shadows and making the image look flat.

Color. The last characteristic in the list is greatly emphasized in underwater photography. This one challenges underwater photographers on a whole other level beyond what land photographers face, and it is, of course, color.

Lighting an image warmer (more yellow) or cooler (more blue) can also influence the mood in obvious ways. Whether working with natural light or strobes, it is important to remember that water acts as a color filter. The greater the depth, the more abruptly warmer colors are filtered out. This also applies to horizontal distance. That is why it is important to eliminate the water column between the lens and the subject—to get more accurate colors.

When using natural light, I recommend that you use Magic Filters to compensate for the color deviation that water creates. White balancing and natural light can allow retention of color to a greater distance than a strobe. However, a strobe gives more control.

Application

So what does all this mean? How does one apply this information? That is like asking, “What am I supposed to say next?” These are merely some of the rules of the language of light, but expression is up to the individual. This is the fun and creative part of being a photographer.

Everyone has their own bag of tricks—lighting techniques that are tried and true. Breaking out of a routine is hard. Humans are creatures of habit and will opt for what they know rather than take a chance on something new. But it is important to ask: “Am I a diver with photography gear or a photographer with dive gear?”

Learning all of the information is quicker done on land than down below where nitrogen slows thought. Learning light theory does not happen overnight. It takes months and months of practicing every day to have the information sink in on a subconscious level. Often, adding such information can cause one to feel like we become worse before we become better. This is a normal process of reconfiguring and applying a sophisticated level of understanding.

Once it all sinks in and begins to make sense, the added benefits are worth the effort. The ability of foresight is gained. Being able to picture an image in the mind’s eye and figure out the lighting requirements before finding the subject in nature allows for efficient and accurate results.

Photography is about the subtleties, and it is much easier to observe these subtleties with a greater understanding of light. The characteristics of light can be observed in every image. By spotting and distinguishing each characteristic, a student is able to reaffirm his or her own knowledge.

Certainly, nobody is perfect, and there is no such thing as the perfect photograph. Applying what is learned is the only way to improve. However, the rules are merely a guideline. After learning and applying them, break them! For example, create a high key image with a dramatic or moody subject matter, or vice versa.

Anomalies exist and often pave the way for some of the most profound images, but everyone must begin with a good foundation. Having good gear, but no understanding of its potential, is unacceptable. ■

Tony Myshlyaev is a formally trained Canadian underwater photographer based in Koh Tao, Thailand. More of his content and prints are available at .

Originally published

on page 83

X-Ray Mag #71

January 06, 2015 - 21:53
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