Before you take your camera out into the field, take a minute to read up on the flash modes you'll be using under varying light conditions. While this information is specific to the Nikon SB-800, it will help guide your understanding of other flash units as well.
Flash Functions
This button turns the flash unit on/off.
Flash head will typically tilt from 90 to -7 degrees and will rotate 180 degrees. As the flash is adjusted, the flash head inside of the flash will move forward and back depending on the setting and the amount of light needed. This changes the angle at which the light spreads out.
To access the custom setting modes, hold SEL for two seconds.
This button allows you to increase or decrease the values in your image. Use left and right to highlight an item, and then use the + and - buttons to make changes.
The back panel illumination light will light up the back panel in low light situations. It's important to remember that when the flash is attached to the camera and the camera is illuminated, the flash will also illuminate.
The stand by mode conserves power.
In the event that you must reset all settings to factory default, hold both buttons for two seconds. Doing so resets all settings to factory default.
The sync cord connection is how the flash and the camera communicate when to fire. This is best used in a studio set up.
Flash Modes
This mode allows the photographer to select all controls for exposure.
When to use it: Use Manual mode in controlled studio situations when you want to control the look and feel of the lighting.
The flash fires a series of pre-flashes that reflect back to the camera, telling the camera to communicate with the flash to determine the proper flash output. These pre-flashes are so fast that many photographers do not notice them when shooting.
When to use it: Use this mode for shooting uncontrolled action, combat camera scenarios, awards and presentations, etc.
In this mode, flash output level is automatically controlled for a well-balanced exposure.
When to use it: Use this mode primarily for balancing the fill flash to the daylight. This is good for outdoor situations.
The commander function in Advanced Wireless Lighting enables the flash to act as a commander unit during wireless multiple flash shooting to trigger remote flash units without firing itself. This operation will not normally affect the correct exposure of the subject; although exposure might be affected if the subject is close and a high ISO sensitivity has been set. To limit this effect as much as possible, bounce the light by tilting or rotating the flash head.
Flash Information
Electronic Flash Safety
When using an electronic flash unit, you are dealing with electricity in the form of a capacitor. Stay away from water and explosive fumes (open fuel). The capacitor in the flash has enough output to potentially kill. Always remember that one tiny spark in the right environment could turn explosive vapors into a fireball capable of destroying you and everything around you.
Do not discharge the flash into people’s eyes. This can cause a brief period of blindness (spots) and can cause permanent damage if done repeatedly. Maintain a safe distance (3 feet or more).
Synchronization
Synchronization describes the action of the flash unit firing while the camera shutter is fully open. As long as the flash fires between the time the shutter opens and closes, then synchronization will occur.
Depending upon which camera model you use, synchronization may occur at a maximum of 1/60th of a second (older cameras), or as fast as the camera can shoot when a “Nikon Creative Lighting System” compatible flash is used in conjunction with a fast sync compatible camera. Older cameras can only sync as fast as 1/60th of a second. With the SB 800 flash unit, the camera will sync up to 1/8000th of a second when the user sets the camera (not the flash) on the “1/250s (Auto FP)” setting under the “Custom Settings” menu.