TTL II Smarter Flash Performance

E-TTL II: Smarter Flash Performance

Canon’s high-end Digital SLRs employ E-TTL II, the most advanced flash metering technology, to solve problems encountered by photographers. Occasionally, if you lock focus and recompose your shot, this could result in a non-optimal exposure with previous systems. E-TTL II remedies this by ignoring the active focusing point, considering distance information and evaluating pre-flash information immediately before the exposure occurs. Sometimes in flash photography, mirror-like objects in the image cause the sensor to register localised, abnormally high levels, and would result in underexposure. E-TTL II knows to ignore

those levels, resulting in the correct exposure. This feature is useful when shooting a subject with a highly reflective object in the background, or if the subject itself is highly reflective. Metered areas with large discrepancies between ambient and pre-flash readings are excluded or down-weighted because they are assumed to contain a highly reflective subject. These readings are weighted, averaged and compared with the ambient light reading and the main flash output is then set and stored in memory, ensuring consistent flash output through a number of shots.

Speedlite 580EX

nApprox. 25% faster recycling time compared to previous 550EX.

nSuperior evenness of exposure, centre to corner of frame.

nSlightly higher max. guide number at 105mm setting (GN 58–meters at ISO 100).

nAuto conversion of flash coverage with compatible Digital SLRs.

nWhite Balance info communicated instantly to compatible Digital SLRs.

nFull swivel, 180° in either direction (first TTL flash with this ability).

nAF-assist beam now compatible with all AF points on every EOS SLR.

nSelect Dial for easy inputs and user control.

Speedlite 430EX

nSignificantly greater user control via new LCD panel on rear of flash.

nWide-angle pull-down panel covers 14mm lens (on a full-frame camera).

nSlightly higher max. guide number at 105mm setting (GN 43–meters at ISO 100).

nAuto conversion of flash zoom coverage with compatible Digital SLRs.

nWhite Balance info communicated instantly to compatible Digital SLRs.

nBounce upward to 90°; swivel right (to 90°) and left (180°).