no0b question: new to the 580exII

I've finally bought a 580EXII, and I have a quick and easy question.

In ETTL (i think is the automatic mode), for example: if its near sunset and you take a picture of a couple, is there a way to see what power the flash is going to use or did use? just curious

I'm taking some prom pictures this weekend with it and its going to be near sunset maybe even night, and i'll wanna see how much the flash is working, and i'll want to probably switch to M to "drag the shutter" to hopefully get some ambient light

Any advice?

aparis99 wrote in post #7821753
I've finally bought a 580EXII, and I have a quick and easy question.

In ETTL (i think is the automatic mode), for example: if its near sunset and you take a picture of a couple, is there a way to see what power the flash is going to use or did use? just curious

I'm taking some prom pictures this weekend with it and its going to be near sunset maybe even night, and i'll wanna see how much the flash is working, and i'll want to probably switch to M to "drag the shutter" to hopefully get some ambient light

Any advice?

There is a way to know what the flash will use.
It is whatever you set in the compensation.

You can drag the shutter with the flash in ETTL mode.

Unfortunately you won't know what the flash is using in ETTL. And FEC is just an adjustment from whatever power the flash/camera sees as needed for normal exposure - which you don't know.

I'd just use M on the camera and ETTL on the flash and adjust FEC to taste.

Titus213 wrote in post #7822074
You can drag the shutter with the flash in ETTL mode.

Unfortunately you won't know what the flash is using in ETTL. And FEC is just an adjustment from whatever power the flash/camera sees as needed for normal exposure - which you don't know.

I'd just use M on the camera and ETTL on the flash and adjust FEC to taste.

+1. This will save you a ton of heartache. Let the camera meter off of the back ground and expose for it and then let the flash do it's thing.

Titus213 wrote in post #7822074
You can drag the shutter with the flash in ETTL mode.

Unfortunately you won't know what the flash is using in ETTL. And FEC is just an adjustment from whatever power the flash/camera sees as needed for normal exposure - which you don't know.

I'd just use M on the camera and ETTL on the flash and adjust FEC to taste.

+2.

ok, now what about after taking a shot. Is there a way to see what power was used? I would think it would help me learn where to start out in M mode in diff environments. I'd also like to do some comparisons with and without a diffuser etc...

No, there is no way to know the power. You can not even easily measure it with a meter because of the pre-flash. You have to resort to FEL and then measure the flash. And the beauty/problem with ETTL is that it changes with every shot based on the scene.

Titus213 wrote in post #7822074
You can drag the shutter with the flash in ETTL mode.

Unfortunately you won't know what the flash is using in ETTL. And FEC is just an adjustment from whatever power the flash/camera sees as needed for normal exposure - which you don't know.

I'd just use M on the camera and ETTL on the flash and adjust FEC to taste.

+3