General Information
■Improved reliability of direct contacts
1. Metal mounting foot
The mounting foot is now made of metal instead of molded plastic. With higher rigidity
and less chance of breakage due to shock, the reliability is improved.
2. Improved communication reliability
In the past, there have been cases where the Speedlite's metallic contacts rubbed against
the hot shoe's molded plastic as the Speedlite was attached to the camera. This generated
dust which stuck onto the contacts and caused faulty connection and communications.
The 580EX II's shape of the contacts has been changed to make the contact's surface
smaller. The contact's torque has also been reduced. These countermeasures reduce
the frictional dust generated with the EOS-1D Mark III's new hot shoe, and improve the
connection and communications reliability.
■Shorter recycling time
Thanks to an oscillator circuit whose frequency is controlled by a microcomputer, the ash
recycling time is approx. 20% shorter than with the 580EX (approx. 4.6 sec. to approx. 3.7
sec.).
* With four new LR6 batteries. Right after the pilot lamp lit, the Speedlite was red 10 times, and the time
required for the pilot lamp to light again for the 11th ash was measured.
■Safety measures against external power packs
If the external power pack terminal is connected to a power pack having 340 V or higher,
the pilot lamp blinks as a warning and the circuitry is cut o. This prevents the Speedlite
from damaging in case of 340 V or higher voltage is generated due to malfunction or
alteration. Reliability is thus enhanced.
■Silent recycling
Thanks to the oscillator circuit whose frequency is controlled by a microcomputer, the
oscillation frequency is increased (70 KHz) beyond the hearing ability of humans. This
makes the recycling sound inaudible.
* The hearing ability of humans ranges from 20 Hz to 20 KHz.
■External metering sensor
An external metering sensor has been provided in response to pros who really wanted it.
1. 580EX II's external metering system
The 580EX II's external metering system works with the ash reecting o the subject
measured by the external metering sensor. In accordance with the ISO speed and
aperture set for the Speedlite, the ash exposure is obtained in real-time. When the
correct exposure level is attained, the ash is cut o. It is an orthodox system. The
external metering sensor angle is approx. 20º.
2. External metering modes
Two modes are provided: Auto external metering and manual external metering. Auto
external metering works with the EOS-1D Mark III and newer EOS digital cameras. The
ISO speed and aperture information from the camera are sent to the Speedlite which
then controls the ash output accordingly. Flash exposure compensation can also be
set. Manual external metering can be used with all EOS SLR cameras. The ISO speed and
aperture are entered to the Speedlite manually. However, ash exposure compensation
cannot be set.
