Photography is all about lighting.  Learning how to use the available light effectively, changing its characteristics and behavior, and the use of supplemental lighting is what allows photographers to create and mold subjects.  Used properly, lighting creates the photograph's mood, enhances the subject, directs attention, and conveys emotion.  The exact same subject can appear happy, sad, solemn, angry, or any other emotion we want it to, simply with the effective use of lighting.

There are many different types of light sources and numerous lighting techniques.  In this section we will go over some basic lighting scenarios.

Flat lighting
In this example, the lighting is flat; it casts no shadows.  It is also harsh, rendering the smallest details in a well defined manner.  Although it works well in this particular case, it does so only because its use was appropriate for this particular shot.

The on-board popup flash built into many consumer cameras tends to produce this flat type of lighting.  When used on subjects where definition is desired, the results are typically unflattering and cookie cutter.

This is one of the reasons professional cameras do not have pop-up flashes.  Professionals light their subjects in a variety of ways and seldom, if ever, light their subjects using a popup flash.

Front Lighting
Using the flash directly in front of our subject, as in this photograph, we light the front of the fire shrimp to place emphasis on the shrimp's face.  By highlighting the busy nature of the front appendages, it brings a menacing look to this otherwise peaceful shrimp.  Combined with the angle of the shot, it appears the shrimp is charging and instills a sense of uneasiness and fear.

Top Lighting
Lighting from the top creates the same view of the subject a casual observer in nature would see.  This is one of the easiest ways to light a reef tank setup; just shoot under the normal lights.  Topside lighting can also be focused and directed with a flash unit.  In this example, a strobe was directed at the center of the anemone.  This has the effect of emphasizing the anemone's translucent nature with an inner glow.

Lighting From Underneath
This type of lighting is to be avoided on human subjects, unless that "evil look" is desired.  Normally we see humans lit from the top (sun).  Lighting from underneath is something we are not accustomed to and instills a sense of uneasiness.  With corals and inanimate objects this lighting effect can yield quite a different result.

Side Lighting
Side lighting in photographs creates pop that makes the photos jump out of the page.  When lighting from the sides, a typical lighting ratio used is a 2:1 ratio, where the main source of light is twice as powerful as the light on the opposing side. This can be accomplished in a number of ways.  We can either use ambient light to light the dark side, use a second flash, or use a reflector.

A reflector is any device that reflects light.  A mirror would be close to a perfect reflector, in that it reflects nearly 100% of the light directed at it.  In photography, this mirror is usually dulled so it scatters some of the light directed at it, yielding a softer source of light.  The result of soft lighting is a smooth graduation from brightness to shadow.  Harsh lighting creates shadows uniform in darkness and containing hard edges.

A white piece of paper can be a simple reflector, and is often used, as it dramatically cuts back on the amount of light reflected back and softens the light very effectively.  In studios, we often see white Foamcore used for this purpose.  Other variants include gold metallic reflectors, which add warmer tones to the reflected light, simulating the effect of a setting sun.

In this example, harsh side lighting in a 1:0 ratio was used for a dramatic effect.  The lighting, here, emphasizes the nocturnal nature of this coral.  Coupled with the marine snow and the use of white space to the right, the photograph tells the story of a deep sea submersible, lighting up the ocean night with its powerful beams, as seen by a fish.