Ben Herrmann wrote:
7. Metering and Exposure quality. Unless I’ve overlooked something (and you other M100 owners please set me straight here), the only issue I have (and it very well might be something I‘ve overlooked somewhere) with the M100 is that the metering seems seems to be biased to where the AF point is. This can result in many under and over-exposures. For example, if I place the AF point on a bright area - let’s say the top of a tree line near the sky - the meter will read this as being overly bright and the image will be anywhere from 1/3 to 1 full stop underexposed. And vice versa, if I place the AF point in a shady area, the image will often be overexposed by the same amount. And yes, before you say it, I am using the "evaluative" metering (not spot) mode, along with using the single AF point (small square size) AF option.
Yes, Evaluative Metering is tied to the autofocus system. The assumption seems pretty straightforward: you're going to lock the AF point on your subject. So whichever AF point locks, the metering segment covering that AF point is picking up your subject.
But it's not simply using the metering at that one point. Evaluative metering also examines the brightness of the segments around the one at the locked AF point, and the brightness of segments farther away. Based on its analysis of the brightness patterns, it determines how much the exposure should be adjusted up or down.
Notice that when you lock AF, Evaluative Metering immediately locks exposure. That way you can recompose without confusing the metering system.
Spot, partial, and center-weighted average are concerned with the center, and don't care about AF. A few of Canon's most expensive DSLRs do offer the option of linking Spot Metering with the AF point, but as far as I know, the M100 doesn't.