APERTURE_VALUE

Value is unsigned double The actual aperture value of lens when the image was taken. To convert this value to ordinary F-number(F-stop), calculate this value's power of root 2 (=1.4142). For example, if value is '5', F-number is 1.4142^5 = F5.6

          FNumber = Math.exp( ApertureValue * Math.log( 2 ) * 0.5 );
          

See Also
#F_NUMBER