Exposing for birds on water

Hi, I hope this doesn't sound like a daft question, but when I'm taking photos of water fowl on water the result is that the bird is generally always slightly underexposed which I guess means that the camera is exposing for the brighter water. I shoot generally in av mode on the 7d and have tried evaluative and spot metering but still can't quite get it right. I've done some exposure compensation, but still not hitting the sweat spot. Is it possible to ask what you guys do for your technique and whether there are any tips or tricks I should try.

Hope you can advise.

Simon

It really depends on many factors including (but not limited to) the color of the water, sun angle, light intensity etc.
Try starting out @ +1 and go from there, up or down as needed..
Use your histogram to verify the exposure and learn what compensation works for the different water conditions.

Simon,

See this post here on my blog.

http://www.wildscapeimages.biz/blog/?p=345

Your camera, seeing what is basically a bright BG, is exposing to make the image a middle gray (18% gray) as this is what the meter is calibrated for. You need to add exposure to correct for this. James is right - add exposure. White bird on bright water will be +2 normally. White bird in full sun and water blue (no longer bright) and you are probably in the -1/3 to + 1/3 range depending upon the brightness of the bird and darkness of the water.

If you have an incident meter, and the light is fairly constant (no clouds). Measure the light and use these settings to shoot in manual.

Simon, not a daft question at all. I often shoot in manual mode and spot meter on a mid tone. If I can't find a mid tone in my scene, then I choose a white or a black and then compensate. A histogram check will confirm if you're in the ball park and then you can tweak to your personal preferrence. I didn't think this method up, Chas Glatzer taught it to me. It's not better or worse than what has been suggested. Any of the above will get you to the same place if you understand what it is that the camera is telling you and then you know what to do with that information. I think that the trick is to find what works for you.

Thanks for all the advice. I today tried spot metering with some exposure compensation which worked much better. hopefully I'll put it all into more practice over the coming weeks.