Originally Posted by
Colin Southern
I think we might need to take a step back and ask ourselves "why are there various metering modes in the first place?" Put simply they're just a way for us to tell the camera which parts of the scene are important to consider. Normally, all you'll need is Evaluative; it's quite capable of figuring out what's white, what's black, and exposing them correctly. In the case where there's something of interest in the middle, but something (like back lighting) towards the periphery of the shot that might throw off the metering then partial might be a better bet. Spot metering says "only what's under the spot is important", but spot-metering makes you work harder because there are likely to be only a narrow range of tones in the metered portion - so it's far far far far more likely that you'll need to enter a correction to offset the amount the subject varies from a middle gray -- and at a wedding you don't have time to much round with that. I'd be using evaluative - dial in the aperture I need - see what my shutter speed was - up the ISO if it was too low, lower the ISO if the SS was too high - and start shooting. You won't need to change ISO unless shooting conditions change dramatically.
Just make sure highlight alert is turned on; if you're getting blinkies in important areas (like Bride's dress) just dial in some -VE EC. If you're shooting RAW (as you should be) then with evaluative metering and no EC you'd have to try pretty hard to much up the exposures to the point where the image couldn't be recovered. Just don't under-expose at high ISO. If there are no blinkies and the image looks reasonable on the review screen then move on to the next shot; you're going to be averaging 3 or 4 shots a minute for hours -- no time for gray cards I'm afraid.
On that note - make sure you have enough charged camera and flash batteries. And enough cards.
Edit: For what it's worth, outside on a sunny day, Use evaluative, Av mode, and dial in -1EC to stop things washing out, and -0.67 FEC so you don't get an over-flashed look - you should be good to go with those settings. Inside during the day you can probably use same mode, but at 400 / 800 ISO and probably lose the -1EC. Inside at night (artificial lights) you just have to go with the flow on that one - I'd be manual - reasonably high ISO - and just work the settings; in those circumstances at least a monopod would be helpful (and have any IS modes on).