There are several EOS bodies with an on-board spot meter, but the methodology and application differs for each. On the EOS 1N, the single level spot meter is designed for assessment of parts of the scene to read off differences in the calculated exposure. It has no 'layering' or averaging function, which limits its application. This implication is that the 1N's spot meter requires a requisite understanding of tones and their importance, rather than trusting, arbitrary placement and reliance on the spot meter in the frame to provide a correct exposure, which because of its simple design, it not actually guaranteed unless you are aiming it at a part of the scene that approximates a light to moderate mid-tone. The EOS 1V however took spot metering to a multi-level averaged approach equal to using a hand-held spot meter. The capacity to shift the meter point around, and 'pancake' several readings, then average them, with one of highlight, midtone or shadow bias, was a big step over the 1N's rudimentary meter. The EOS 3 was a hybrid variation that came after the 1N. In summary, a single spot metering function is not as useful as a 8- or 9- level multispot/shifting spot metering facility but you must first clue up on what to meter, where and when. In skilled hands, multispot metering can far surpass the results provided by evaluative/multipattern/matrix metering systems.