an equation
Exposure Date: 2009:02:22 23:19:26;
Make: Canon;
Model: Canon EOS 5D;
Exposure Time: 1/160.0 seconds s;
FNumber: f/20.0;
ISOSpeedRatings: ISO 320;
ExposureProgram: Other;
ExposureBiasValue: 0
MeteringMode: Other;
Flash: Flash fired, compulsory flash mode;
FocalLength: 100.0 mm mm;
Software: Adobe Photoshop CS5.1 Windows;