TIFF Tag Flash

Description

Indicates the status of flash when the image was shot.

Bit 0 indicates the flash firing status, bits 1 and 2 indicate the flash return status, bits 3 and 4 indicate the flash mode, bit 5 indicates whether the flash function is present, and bit 6 indicates "red eye" mode.

Values for bit 0 indicating whether the flash fired.
0 = Flash did not fire
1 = Flash fired

Values for bits 1 and 2 indicating the status of returned light.
00 = No strobe return detection function
01 = reserved
10 = Strobe return light not detected
11 = Strobe return light detected

Values for bits 3 and 4 indicating the camera's flash mode.
00 = unknown
01 = Compulsory flash firing
10 = Compulsory flash suppression
11 = Auto mode

Values for bit 5 indicating the presence of a flash function.
0 = Flash function present
1 = No flash function

Values for bit 6 indicating the camera's red-eye mode.
0 = No red-eye reduction mode or unknown
1 = Red-eye reduction supported

Not all combinations make sense though. The specification defines these combined values:

hex 0000 = Flash did not fire
hex 0001 = Flash fired
hex 0005 = Strobe return light not detected
hex 0007 = Strobe return light detected
hex 0009 = Flash fired, compulsory flash mode
hex 000D = Flash fired, compulsory flash mode, return light not detected
hex 000F = Flash fired, compulsory flash mode, return light detected
hex 0010 = Flash did not fire, compulsory flash mode
hex 0018 = Flash did not fire, auto mode
hex 0019 = Flash fired, auto mode
hex 001D = Flash fired, auto mode, return light not detected
hex 001F = Flash fired, auto mode, return light detected
hex 0020 = No flash function
hex 0041 = Flash fired, red-eye reduction mode
hex 0045 = Flash fired, red-eye reduction mode, return light not detected
hex 0047 = Flash fired, red-eye reduction mode, return light detected
hex 0049 = Flash fired, compulsory flash mode, red-eye reduction mode
hex 004D = Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected
hex 004F = Flash fired, compulsory flash mode, red-eye reduction mode, return light detected
hex 0059 = Flash fired, auto mode, red-eye reduction mode
hex 005D = Flash fired, auto mode, return light not detected, red-eye reduction mode
hex 005F = Flash fired, auto mode, return light detected, red-eye reduction mode