Date of manufacture from serial number help

[nigpd]

I'm going to be selling my Canon 600mm f4 mk1 that I bought new from Walters Photo in 2011, but I want to get some info about the lens first.

I know it was made some time earlier than 2011, but I'm not sure exactly when. I've done a search on a site that deciphers codes, but the code of 25855 on my 600 doesn't look like anything on the site.

Does anyone have any ideas as to how I could find out when the lens was built? I've emailed Canon, but suspect it could be quite a while before they reply. TIA

 

[Canon Bob]

At that age it will have the older coding system.....two letters and four numbers stamped or etched on the lens mount (on the same face as the electrical contacts)

Bob

 

[sureshot]

https://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Aging.aspx

 

[nigpd]

Thanks Bob & Nick, found it. Your help is much appreciated