WIKI-2H

Off-Camera Flash

Reasons for Using Off-Camera Flash

  • Control over the quality of light: Off-camera flash allows for shaping and modifying the light.
  • Control over the direction of light: Light can be positioned to create desired lighting patterns.
  • Control over the lightness or darkness of backgrounds: Flash power can be adjusted to balance the subject and background.
  • Control over the quantity of light: The amount of light on the subject can be precisely controlled.

Larger Light Sources & Softer Light

  • Moving the flash off-camera allows the use of various lighting modifiers like umbrellas and softboxes.
  • These modifiers transform the small flash head into a larger light source, producing softer light.

Directional Lighting

  • Off-camera flash enables the creation of specific directional lighting patterns.
  • Additional flashes can be used as fill lights, hair lights, background lights, or kicker lights.

Consistent Exposures

  • With off-camera flash on a stand, the flash-to-subject distance remains constant.
  • The photographer can move freely without needing to constantly adjust exposure settings.

Monolights vs. Speedlights

  • Speedlights can be used off-camera with stands and adapters.
  • A remote trigger is needed for speedlights.
  • Monolights are designed for light stands and often have built-in radio receivers.
  • Transmitters on the camera can control monolight output, even controlling multiple monolights simultaneously.
  • Monolights generally offer more power and a wider range of modifier options compared to speedlights, making them a better choice for outdoor and on-location work.

Determining Exposure with Off-Camera Flash

  • Many factors influence the amount of light on the subject:
    • Flash power
    • Flash zoom head position
    • Flash output settings
    • Flash-to-subject distance
    • ISO value
    • Lighting modifiers
  • An incident light meter is the most reliable way to measure flash output.
  • Take a test exposure with the meter at the subject's position to determine the resulting f-stop.

Lowering Flash Output

  • Both speedlights and monolights allow adjusting flash output (like a dimmer switch).
  • Adjustments can be in full stops, 1/3 stops, or 1/10 stop increments.
  • Some speedlights use ratio values to indicate output.
Ratio Settings:
  • 1/1 = Full Power
  • 1/2 = 1 stop reduction
  • 1/4 = 2 stops reduction
  • 1/8 = 3 stops reduction
  • 1/16 = 4 stops reduction
  • 1/32 = 5 stops reduction
  • 1/64 = 6 stops reduction
  • 1/128 = 7 stops reduction
Simplified Power Down:

  • Some flashes use a numerical scale (e.g., 9 or 10 for full power).

  • Each number decrease represents a one-stop reduction.

  • Example:

    • 9 = Full Power
    • 8 = 1 stop reduction
    • 7 = 2 stops reduction
    • 6 = 3 stops reduction
    • 5 = 4 stops reduction

Balancing Flash and Ambient Light

  • Balancing flash and ambient light is key to successful off-camera lighting.
  • Example: Ambient exposure at f/8 and 1/125.
  • Flash meter reading of f/11 at power level 8 on a monolight (full power is 9).
  • Equivalent speedlight setting is 1/2 power.

Adjusting Flash for Natural Look

  • If the background is brighter than the ambient light on the subject, flash can make the subject look 'flashy'.
  • Adjust flash to match the exposure of the background and the subject.
  • Example: Ambient light at f/4 and 1/125.
  • Off-camera flash set to one stop less than ambient (f/2.8) creates subtle highlights and shadows without an obvious flash look.

Flash Meters and % Readout

  • Flash meters can help set the flash relative to ambient light.
  • The % readout compares flash output to ambient light.
  • 50% = ambient and flash are equal.
  • Below 50% = ambient light is dominant.
  • Above 50% = flash output is dominant.
  • A range of 50-75% is good for natural-looking images.
  • Many monolights offer fine-tuning in 1/10th stop increments.