Credit goes to PhotosGuy (Frank C) for the M&Ms idea, which I have shamelessly stolen. A variety of colors, and most everyone knows what they should look like. I added white tic tacs and black licorice to maximize the color gamut.
The idea was to see how the various metering modes on the 300D would read various combinations of colors. Rather than bore you with my conclusions, I'll just tell you how I set this up and let you discuss.
The 300D has three metering modes:
35 Zone Evaluative Metering, the default metering in every shooting mode except Manual. For these shots, I used Av mode at f/8 and let the camera choose the shutter speed. Edit for clarification per discussion and testing later in this thread: All shots were taken in autofocus mode with the center AF point selected. Evaluative metering is weighted according to the active AF point in autofocus mode. In manual focus mode, it is apparently centerweighted, regardless of the active AF point.
Centerweighted Average Metering, the default metering in Manual mode. I set the aperture at f/8 and adjusted the shutter speed to put the exposure indicator needle dead-center.
Partial Metering, which is activated by the AE Lock (*) button, uses a center area comprising about 9% of the frame. These were taken in Av mode at f/8, just like the Evaluative Metering shots.
Before you look at the pictures, you need to understand two vital points. First, every single shot was metered according to what the camera considered to be the "correct" exposure. There was no exposure compensation, no post-processing adjustments. What you see is what I got.
Secondly, the same pieces of candy were used in every shot. I simply rearranged them and tried to keep every piece at least partially in the frame. I did not substitute dark ones for lighter ones or vice-versa.
Every image below is from the same lens at the same distance with the same lighting. I did not move the camera or the light. Every shot was at f/8 and ISO 100. Only the shutter speed was changed via the metering methods described above. Nothing has been cropped. These are full-frame images shot RAW with custom white balance, converted and resized to 260 x 390. No sharpening, no adjustments to hue, saturation, etc., etc.