TTL flash
Manual flash provides a fixed flash intensity irrespective of the brightness of the subject and the camera setting. TTL* flash measures the light from the subject that is reflected through the lens.
TTL metering also has a P-TTL metering function, which adds a pre-flash to TTL metering, and an ADI metering function, which adds distance data to the P-TTL metering.
This flash unit defines all P-TTL and ADI metering as TTL flash and 
is displayed on the LCD panel.
*TTL = through the lens
•ADI metering is possible in combination with a lens with a built-in distance encoder. Before using the ADI metering function, check whether your lens has a built-in distance encoder by referring to the specifications in the operating instructions supplied with your lens.
