RECORDING MODE
FLASH CONTROL
ADI, pre-flash TTL, and manual flash controls are available. Flash control is changed in the basic section of the recording-mode menu (p. 78).
ADI flash metering – Advanced Distance Integration. This mode combines distance information from the autofocusing system with information from a pre-flash exposure. Unlike conventional TTL flash metering, ADI is not influenced by the reflectance of the subject or background ensuring optimum flash exposures.
Pre-flash TTL – calculates flash exposure with a pre-flash only. This mode must be used when using close-up filters or filters that reduce the amount of light entering the camera such as neutral density filters. Pre-flash TTL must be used when a diffuser is attached to the built-in flash or an external flash unit.
The camera will automatically switch from ADI metering to pre-flash TTL when a low-contrast subject is preventing the autofocus system from focusing. If the autofocus system cannot lock on the subject, press the AF/MF button and manually focus; the ADI metering will remain in effect.
Manual flash control – fires the flash at full power, 1/4 power, or 1/16 power. The power output is selected in the basic section of the recording-mode menu (p. 78). Because no pre-flash is used, man- ual flash control can be used to fire slave flash units.
The chart lists approximate guide numbers for manual flash calculations. The following equations are useful in determining the guide number, aperture (ƒn), or flash-to-subject distance required for expo- sure.
Guide no. (for distance in meters / feet)
Manual | Camera sensitivity (ISO) | | |
flash | 100 | 200 | 400 | 800 |
| | | | | | |
Full | 8 | / 26 | 11 / 36 | 16 / 52 | 22 | / 72 |
1/4 | 4 | / 13 | 5.6 / 18 | 8 / 26 | 11 | / 36 |
1/16 | 2 | / 6.6 | 2.8/9.2 | 4 / 13 | 5.6 | /18 |
Guide no. = ƒn. X distance | | |
Guide no. | = distance | Guide no. | = ƒn. |
ƒn. | distance |
