Canon Flash EXIF
Posted on January 13th, 2009 in Aperture, Photography
I’m not sure what the numbers mean, but I’ve been digging and have determined that at least for Canon cameras, the EXIF Flash tag will be either a 1 a 73 or a 25 (and possibly other numbers). The number seems to correspond to the age of the camera. My DSLRs and G10 all seem to use 73, Gina’s SD700IS uses 25 and my old PowerShot S50 uses 1.
I should try shooting with an external flash to see if the number is different.
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January 2nd, 2010
Here’s what google spit out for the numbers in the flash field:
“0″ => “Flash did not fire.”,
“1″ => “Flash fired.”,
“5″ => “Strobe return light not detected.”,
“7″ => “Strobe return light detected.”,
“9″ => “Flash fired, compulsory flash mode”,
“13″ => “Flash fired, compulsory flash mode, return light not detected”,
“15″ => “Flash fired, compulsory flash mode, return light detected”,
“16″ => “Flash did not fire, compulsory flash mode”,
“24″ => “Flash did not fire, auto mode”,
“25″ => “Flash fired, auto mode”,
“29″ => “Flash fired, auto mode, return light not detected”,
“31″ => “Flash fired, auto mode, return light detected”,
“32″ => “No flash function”,
“65″ => “Flash fired, red-eye reduction mode”,
“69″ => “Flash fired, red-eye reduction mode, return light not detected”,
“71″ => “Flash fired, red-eye reduction mode, return light detected”,
“73″ => “Flash fired, compulsory flash mode, red-eye reduction mode”,
“77″ => “Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected”,
“79″ => “Flash fired, compulsory flash mode, red-eye reduction mode, return light detected”,
“89″ => “Flash fired, auto mode, red-eye reduction mode”,
“93″ => “Flash fired, auto mode, return light not detected, red-eye reduction mode”,
“95″ => “Flash fired, auto mode, return light detected, red-eye reduction mode”
March 26th, 2010
You can grab the EXIF spec over here:
http://www.exif.org/specifications.html
And the Flash tag spec starts on page 35. But let me save you the time, unless you are really feeling Geeky: The spec uses hex to encode a 7 bit sequence used to describe flash activity. The list that Dr Bob gave above is the decimal conversion of the hex and looks to be how it sometimes gets stored in the file. Not sure that is always true, so if you ever run into a value in that field that does not match to the above list you can try converting it from hex to decimal and see what you get.
R,
Coby
March 31st, 2010
Thanks for finding that!