![sigma serial numbers lens sigma serial numbers lens](https://www.kenrockwell.com/sigma/images/8-16mm/D3S_5699-460.jpg)
The HEX number that correlates to the stamped serial number 1520708485 is "5AA42B85".
SIGMA SERIAL NUMBERS LENS PROFESSIONAL
This number is correctly reported by Digital Photo Professional as the camera's serial number. Yet the Serial number stamped on the camera body is 1520708485. Using a standard converter yields a decimal value of 24331227457. The value for 'Camera Serial Number' in the EXIF maker notes of images taken with my Canon 50D is 5AA411141. This may also be the case regarding lens ID numbers with bodies that can differentiate between two different copies of the same model lens. Many Canon camera bodies have a separate internal serial number that doesn't match the one stamped on the exterior of the camera, at least not when the number in the EXIF is translated using a standard hex to decimal converter. Images taken with my 5D mark II have a blank "Internal Serial Number" value when using Jeffrey's EXIF Viewer. Images taken with my 7D using two different lenses shared the same "Internal Serial Number" with each other, a different number than the three images taken with three lenses using the 50D shared. Even though the the lens ID immediately precedes the "Internal Serial Number" value, it may not accurately reflect the serial number of the lens used to create the image. This leads me to believe the "Internal Serial Number" value is a reference to the camera body, not the lens (at least on older Canon bodies that do not differentiate between two different copies of the same lens model for various purposes such as AFMA). The two Canon lenses were correctly identified in the "Lens Model" field (The Tamron was identified as a "Canon EF 28-70mm f/2.8L or Sigma or Tamron Lens" because many Tamron and Sigma lenses are known to spoof the lens ID for the older EF 28-70mm f/2.8L).
![sigma serial numbers lens sigma serial numbers lens](https://i5.walmartimages.com/asr/00e6339a-1224-4d8b-b931-ab84343bf6df_1.2a71676e1e550cce84bcecab351f7774.jpeg)
Each image was taken with, respectively, a Tamron SP AP 17-50mm f/2.8 XR Di-II, an EF 70-200mm f/2.8 L IS II, and an EF 28-135mm f/3.5-5.6 IS. The 'Internal Serial Number' value returned by Jeffrey's EXIF Viewer was the same value for all three images taken with the same camera and three different lenses. I tried the Jeffrey's EXIF viewer with three images taken with the same camera (a Canon 50D) and three different lenses.