If you’re ever buying a Nikon camera or lens and the seller tells you they purchased it brand new, there’s a very easy way to see at a glance whether it was actually factory refurbished. Simply glance at the serial number and look for a “secret code.”
Photographer Paul Eichengrun writes that Nikon physically marks every piece of equipment that it refurbishes. If your lens, camera, or flash was previously returned to Nikon, examined, and then resold, then it will have two pin prick circular indentations on the sides of the serial number.
Here’s what the pin pricks look like on the serial number of a refurbished Nikon DSLR:
Photo by Paul Eichengrun
A crop of the above photo showing a closeup of the pin pricks, indicated by red arrows.
Here’s what the marks look like on a refurbished Nikon lens:
A crop of the above photo showing a closeup of the pin pricks, indicated by red arrows.
If the indentations are absent from the serial number area, then the product was never refurbished by Nikon. Eichengrun does note, however, that Nikon aims to ensure that all factory refurbished products are as good as new in every regard.
Culled from
https://petapixel.com/2018/04/02/this-secret-code-shows-if-your-nikon-gear-is-refurbished/
