Canon 30D & 580EX Flash Output

[nitehawk]

During a recent use on FEC, I noticed that one can either set FEC on the camera or on the flash unit. Below are some of my findings:-

1. In-camera FEC+1 & 580EX FEC+0 has almost the same output as On-camera FEC+0 with Flash FEC+1
2. In-camera FEC+1 & 580EX FEC+1 does not result in double luminous.

What is the relationship between FEC set on in-camera and on flash unit? And how does it differs with 40D & 580EXII?

[dwaynefoong]

camera will only read in-camera OR flash unit.

i think in-camera has more priority... i am not too sure lah.

[carllylz]

OMG...can't understand any!!!still lot to learn!

[jayhan]

If I'm not mistaken, on the 40D, the FEC on the camera will have priority if the flashgun is set to be fired at ETTL. If manual then, obviously, all changes need to be done in the flashgun

[mitmivec]

if i am not mistaken the flash will take the reading on the camera first if no setting it will than look for the setting in the flash

[jejaka]

camera will only read in-camera OR flash unit.

i think in-camera has more priority... i am not too sure lah.

it true.. but the flash can also has more priority.. its all about setting/setup