Standard TTL flash - TTL
The TTL sensor monitors the degree of flash illumination exposed on the film surface during exposure, the camera's exposure metering is not used in the exposure calculation.
Matrix **balanced fill-flash - TTL +
In this technique the camera's Matrix light meter adjusts ambient exposure and the TTL sensor adjusts exposure during flash. This is done to balance the flash illumination so that it doesn't overpower the foreground subject. Pre-flash and distance information from the lens are not used. 'Spot' and 'Centre weighted' versions of of balanced fill-flash are available depending on the chosen camera metering mode .
**What is 'balanced' flash?
In this mode the camera uses both the TTL flash sensor and the camera exposure meter to balance the exposure for foreground and background. The resulting exposure produces the most natural balance possible.
3D Multi-Sensor balanced fill-flash - TTL +
The Speedlight fires a series of pre-flashes, just before the first shutter curtain moves. The monitor pre-flashes are detected by the cameras TTL sensor, analysed for brightness and contrast, then integrated with distance information from 'D' or 'G' type lens which is required for this kind of function. It is called 3D because the final exposure is calculated from camera meter reading, information from the monitor pre-flash reading and lens distance information.
This mode accomodates most picture taking picture taking situations including bright subjects, subjects which are off centre and pictures with small subjects against a distant background.
Multi-Sensor balanced fill-flash - TTL +
The same as 3D Multi-Sensor Balanced fill-flash above but if the lens is a non 'D' or 'G' type lens then distance information is not communicated. There are two types of Multi-Sensor balanced fill-flash, one uses monitor pre-flash and the other does not, the type activated depends on the Speedlight and lens in use.
Automatic balanced fill-flash
This is a generic term for automatic flash power control to balance the brightness of the subject in the foreground with the background using the TTL Multi-Sensor (see image of '5 segment TTL Multi-Sensor' below).
For information on Speedlight compatibility and a key for Speedlight LCD indicator icons Click Here.