candid photos with on-camera flash

[MrJones]

Hi,
I've been taking photos at my family fest, we are about 40-45 people so it's a pretty big event .
anyway, I've been using my 580EX II on camera, bouncing off the ceiling and using that little white card to bounce some light forward. I was using ETTL with +1/3 to get more light into the picture but naturally some came out underexposed because of the distance between me and the object which varies all the time (candid photography).
is there a way to deal with it besides actually playing with the flash settings every time?
am I missing something?
I'm used to taking portraits but then you have the time to plan everything from beginning to end.

[BCampbell]

A big part of the problem is that once you start bouncing, the flash has no idea how far away your subject is from the light source -- it doesn't know what you're bouncing off of! If you want something a little more idiotproof you might try putting on a diffuser, pointing the 580 straight ahead so it can use the distance information, and dialing the FEC down a bit.

You also want to stay AWAY from the focus-recompose method, since the difference between the background and your subject is important to the flash. Get used to selecting a focus point on the fly.

[MrJones]

Originally Posted by BCampbell

A big part of the problem is that once you start bouncing, the flash has no idea how far away your subject is from the light source -- it doesn't know what you're bouncing off of! If you want something a little more idiotproof you might try putting on a diffuser, pointing the 580 straight ahead so it can use the distance information, and dialing the FEC down a bit.

You also want to stay AWAY from the focus-recompose method, since the difference between the background and your subject is important to the flash. Get used to selecting a focus point on the fly.

thanks, I'm using to focus points for about a year now so that's not a problem.
a diffuser doesn't really makes a difference since the distance between the light source and the diffuser is about 5cm, won't make a big difference.
maybe I'll just go manual on the flash, that might just work at a scene where the lightning doesn't change that much.

[BCampbell]

Originally Posted by MrJones

a diffuser doesn't really makes a difference since the distance between the light source and the diffuser is about 5cm, won't make a big difference.

Sorry, I meant something like a little sto-fen. Will make a huge difference especially indoors, takes away a lot of the harsh edge, making it a lot easier to use the flash without bouncing.

[bhursey]

I all do is pump the FEC up some on the flash.. Really like said earlier there is no real way of avoiding it when bouncing..

[ddr]

Originally Posted by BCampbell

You also want to stay AWAY from the focus-recompose method, since the difference between the background and your subject is important to the flash. Get used to selecting a focus point on the fly.

Is this important if one is using full manual on the camera and on the flash?

[BCampbell]

Originally Posted by ddr

Is this important if one is using full manual on the camera and on the flash?

No, full manual is full manual. I mentioned that because the Canon system tries to detect your subject and the background and tailor your ambient exposure and flash exposure for each. No idea about the Nikon system but I assume it works similarly.