Automatic Flash Exposure Reduction
The DCS 500 Series camera has a built-in program that automatically controls flash exposure compensation based on the level of ambient light. It applies a standard flash exposure (no compensation) in dark conditions, and a reduced flash exposure level in bright conditions, as shown in the following chart:
AE
0
-1
-2
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 EV
How to read this chart: EV Level is an index of the overall brightness of the scene. Each full EV number represents a 1-stop difference in ambient light level. Higher EV numbers indicate brighter conditions and vice versa. An EV level of 15 on this chart is equivalent to a bright daylight, or sunny 16 exposure level at ISO 100. The chart shows the level of reduction (in EV steps) from a standard flash exposure, in other words an exposure created solely by illumination from the flash, based on the EV level of the scene.
Normally, any flash exposure compensation settings that you set on the camera or Speedlite will be applied in addition to, not instead of the automatic flash exposure level control formula shown above. However, your DCS 500 Series camera is equipped with a Custom Function (F-14-1) which shuts off the flash exposure level reduction algorithm, thus applying a standard flash exposure level in any lighting condition. We recommend the use of Custom Function F-14-1 for anyone who plans on applying their own flash exposure compensation settings, since it allows greater control of the results.
External Automatic Flash Exposure Control with Speedlite 480EG
Speedlite 480EG is unique among current Canon Speedlites in offering optional external automatic flash exposure control. This method does not monitor reflections from the surface of the CCD, and is therefore capable of providing reliable results. For details of operation, please consult the 480EG’s instruction book.
Manual Flash Exposure with Speedlites 540EZ, 480EG, 430EZ & 420EZ
Variable-power manual (non-automatic) flash exposure control is available with Speedlites 540EZ, 480EG, 430EZ and 420EZ. This method requires the photographer to adjust flash exposure manually based on ISO, aperture and flash-to-subject distance.
