off-camera flash question

I plan on using a 580EXll with a 40D. The flash will be mounted high on a stroboframe bracket and the AF-assist beam and external sensor on the front will be completly blocked by the Photoflex mini softbox I plan on using. My question is, if I use the off-camera cord (OCE-3)).. does it allow the flash/camera to auto-expose normaly? I see no sensor on the OCE module, so I question how it all works.. I just purchased the 580 and want to get the best out of it with this sort of setup.

Thanks...

JJ

The OCE-3 has full E-TTL communication with the speedlite.

The light sensor on the front of the 580EX II is used only when set for Auto External Metering (non-ETTL). Normal E-TTL metering is done by the camera, measuring the E-TTL preflash through-the-lens. The softbox should not be any hinderance to (wired) E-TTL function, even if it is blocking the Wireless sensor and the AF-Assist patterned light.

Jackjay said:

I plan on using a 580EXll with a 40D. The flash will be mounted high
on a stroboframe bracket and the AF-assist beam and external sensor
on the front will be completly blocked by the Photoflex mini softbox
I plan on using. My question is, if I use the off-camera cord
(OCE-3)).. does it allow the flash/camera to auto-expose normaly? I
see no sensor on the OCE module, so I question how it all works.. I
just purchased the 580 and want to get the best out of it with this
sort of setup.

Click to expand...

Thanks.. that puts me at ease. I thought it worked like that, but never confirmed it