QUOTE(mosheshmeal @ Dec 11 2007, 11:03 PM)

More like exposure time and shutter speed.
exposure time?? the bird would be a blur if it was set too slow. Right, faster shutter speed:smaller f-stop (as I mentioned above)
QUOTE
And therefore? Auto settings are hardly constant.
If it's left at automatic, it tries to gauge by itself; then if the meter reading was taken off the darker part of the flower or grass, it'd make up for what it thought would be an under-exposed pic and cause the highlights to blow out.