Back when I was shooting chrome it was considered proper procedure, at that time, to meter for highlight detail rather then shadow detail as in the case of negative films. Apparently this has changed from that time. The reasoning was that chrome was a positive medium as opposed to a negative film. I found that highlights were easily blown out by too much exposure and would usually bracket (35 mm) in 1/3 stop increments. First exposure was at the indicated meter reading, second was 1/3 stop lower and last was 1/3 stop above meter reading. When I began shooting medium format the bracketing ceased and I began to meter much more accurately. Since my efforts were being printed on Cibachrome I usually erred on the side of underexposure for purposes of greater color saturation. But as I said at the outset that was some years ago and materials and procedures may have changed since then. It seems that many photographers were actually rating chrome films at higher EI then manufacturers advertised as opposed to lower in the case of negative films. (typically advertised 64 was shot at 80, 50 at 64 etc.)