Metering when using fill in flash

[Prophet]

I shot a wedding on Sunday and overall I'm very happy with the shots I got. However, there was a scene where there was strong back light through a windows and hardly any natural light to brighten the bride. I didn't have much time so bounced the flash off the walls and got an underexposed shot, but one I can save in lightroom.

Exposure in tricky situations is about the only thing I struggle with... What would you guys do to get the correct exposure?

 

[vail3r]

If you anticipate that your camera is going to meter wrong with the backlight, you should at least be able to quickly boost the flash power before taking the shot. Exposure still might be off slightly but will get you closer, just remember to turn the flash back down

 

[Vertigo]

I'd firstly overexpose the ambient slightly, possibly blowing out the background a tad but getting some of the natural light on the subject, then dial up the flash exposure compensation until the subject is lit sufficiently. Bouncing is obviously best for light quality but, depending on the distances involved and the flash unit, can take significant power to light the subject sufficiently.