Camera and lens serial numbers in photos

A camera serial number in EXIF identifies one physical body, not a model. Every photo from that camera carries the same string, so two images posted under different names, on different sites, years apart, can be tied to the same device and very likely the same person. Of all the camera tags, this is the one worth removing before you publish anonymously.

Every place a serial number can hide

The EXIF spec calls tag 0xA431 BodySerialNumber. ExifTool names it SerialNumber, and the difference bites: in ExifTool 12.76, -BodySerialNumber=123 on a JPEG reports "0 image files updated" without an error. The full list of usual locations:

• ExifIFD SerialNumber (0xA431), the body
• ExifIFD LensSerialNumber (0xA435), the lens
• XMP-aux:SerialNumber, written by Adobe software such as Lightroom
• the maker notes, where Canon, Nikon, Olympus and Pentax keep their own SerialNumber or InternalSerialNumber

A test file with the first three filled in:

$ exiftool -a -G1 -s "-*Serial*" photo.jpg
[ExifIFD]       SerialNumber                    : 012345678901
[ExifIFD]       LensSerialNumber                : 0000123456
[XMP-aux]       SerialNumber                    : 012345678901
$ exiftool -a -G -s "-*Serial*" photo.jpg
[EXIF]          SerialNumber                    : 012345678901
[EXIF]          LensSerialNumber                : 0000123456
[XMP]           SerialNumber                    : 012345678901

Searching with the *Serial* wildcard is the quickest audit. A plain -SerialNumber read shows a single copy, while -a with the wildcard lists the duplicates from every group.

Deleting every copy

ExifTool accepts the same wildcard for deletion:

exiftool "-*SerialNumber*=" photo.jpg

That catches LensSerialNumber and InternalSerialNumber too. Run the audit command again afterwards. If a serial survives inside a binary maker-note record, drop the whole block with -MakerNotes:all=. Don't use -MakerNotes:all= or -all= on a CR2 or other proprietary RAW file: converters need the maker notes, so stick to the named tags there.

Our tools are partial here. The reader and editor handle LensSerialNumber but not the body serial, which is not in the whitelist. The metadata remover runs exiftool -all=, so every copy listed above goes, together with everything else in the file. It isn't the only option; see how to remove metadata from photos.