JEITA  CP-3451 - 33 - When this tag records an OECF of m rows and n columns, the values are as in Figure 10. Length Type Meaning 2 SHORT Columns = n 2 SHORT Rows = m Any ASCII 0th column item name (NULL terminated)   : : : Any ASCII n-1th column item name (NULL terminated) 8 SRATIONAL OECF value [0,0] : : : 8 SRATIONAL OECF value [n-1,0] 8 SRATIONAL OECF value [0,m-1] : : : 8 SRATIONAL OECF value [n-1,m-1] Figure 10 OECF Description Table 9 gives a simple example. Table 9 Example of Exposure and RGB Output Level   Camera log Aperture R Output Level G Output Level B Output Level -3.0 10.2 12.4 8.9 -2.0 48.1 47.5 48.3 -1.0 150.2 152.0 149.8 ShutterSpeedValue Shutter speed. The unit is the APEX (Additive System of Photographic Exposure) setting (see Annex C).   Tag = 37377 (9201.H) Type = SRATIONAL Count = 1 Default = none ApertureValue The lens aperture. The unit is the APEX value.   Tag = 37378 (9202.H) Type = RATIONAL Count = 1 Default = none BrightnessValue The value of brightness. The unit is the APEX value. Ordinarily it is given in the range of -99.99 to 99.99. Note that if the numerator of the recorded value is FFFFFFFF.H, Unknown shall be indicated. Tag = 37379 (9203.H) Type = SRATIONAL Count = 1 Default = none