FLASH METERING
Flash metering changes according to the flash unit and lens being used.
| | D lens | Other lenses |
| | | |
| 5600HS(D) | ADI metering | Pre-flash metering |
| 3600HS(D) | (HSS on, with pre-flash) | (HSS on) |
| | | |
| 5400HS | Pre-flash metering | Pre-flash metering |
| (HSS on) | (HSS on) |
| |
| | | |
| Other accessory | TTL metering | TTL metering |
| flashes |
| | |
| | | |
| Built-in flash | ADI metering | TTL metering |
| (without pre-flash) |
| | |
| | | |
| | | |
•When the shutter speed is faster than 1/200 sec, flash metering will be HSS-TTL. If Wireless/Remote flash is set, metering will be Wireless/Remote-TTL.
TTL metering (Through-the-lens):
The TTL flash metering system determines the flash exposure automatically.
Pre-flash metering:
A pre-flash fires before the main exposure. The preflash is metered (14 segment) and fed back to the flash exposure system to more accurately determine the flash exposure.
ADI metering (Advanced Distance Integration):
Flash metering is controlled by the guide number in addi- tion to TTL metering. Flash output is less influenced by the background conditions or the subjects reflectance.
When using an accessory flash with HSS function, and if HSS is turned on, then pre-flash fires and ADI/Pre-flash metering will occur
(blue area of the chart 
). When using a D lens, ADI metering is
also done using the built-in flash ( 
area).
•TTL 4-segment flash metering will be used instead of ADI/Pre-flash metering, when HSS is off, bounce flash is set, or when an off-camera cable is used to connect multiple flash units. TTL average metering will be used instead of ADI/Pre-flash metering when rear flash or the mirror lock-up function is selected.
Use of a Flash/Color Meter with Pre-Flash
When pre-flash fires, a flash/color meter cannot meter accurately. This is because the purpose of pre-flash is to assist ADI/Pre-flash- metering, not to provide illumination for the picture. Cancel HSS (see flash manual) or eliminate the influence on metering using
Custom 20-2/3 (p. 175). Those items affected are in 
in the chart on page 108. However, if you use the test-flash button on the flash, the pre-flash will not fire.
When Using a Close-up Diffuser, Certain Filters and Lenses
When close-up diffuser CD-1000, or a filter whose stop’s increase is not 0 (i.e., ND) is used, or when the focus-range limiter or macro release of certain lenses are used, the proper exposure will not be
obtained by ADI or Pre-flash metering. For those items in 
(p. 108), cancel the HSS or choose Custom 20-2/3. When using the built-in flash
, you must choose Custom 20-2/3 .
•Custom 20 gives you the choice of (1) ADI 4-segment flash metering,
(2) TTL 4-segment flash metering, (3) TTL average flash metering (p. 175).
