The saturation-based (SAT or S sat) technique is closely related to the SOS technique, with the sRGB output level being measured at 100% white rather than 18% gray. The SOS value is effectively 0.704 times the saturation-based value. Because the output level is measured in the sRGB output from the camera, it is only applicable to sRGB images—typically TIFF —and not to output files in raw image format. It is not applicable when multi-zone metering is used.