Nikon’s Creative Lighting System enhances communication between the camera and compatible flashguns. This includes i-TTL (intelligent Through The Lens) flash metering, although recent Nikon Speedlights default to i-TTL-BL (Balanced Light) mode. This combines ambient metering from the camera with flash metering, for a more natural look. This chart shows the flash metering accuracy of each flashgun. Positive values equate to overexposure (too bright), negative values for underexposure (too dark).