Hi guys,
My house was broken into and my Sigma 30mm was stolen (along with a bunch of other stuff :mad. The police have a lead and are inquiring about where they can find the serial number on the lens. Could someone post a pic, or a description of where it is located?
Thank you very much!
-Mark

I believe its on the 'bottom' of the lens, IE the side without the focus distance window..
Just guessing cause thats where it is on my 50mm

Yep. Opposite the AF/M switch and below 'LENS MADE IN JAPAN'.

Ok, that's what I was afraid of.
Well, the cops did a raid this morning on a house 25 miles away, and we recovered a laptop and some costume jewelry (family heirloom). They recovered a Sigma 30mm lens as well, so it would seem likely to be mine. They took a picture of the serial # but it only has 7 digits, and doesn't match my warranty card (which has 8 digits). I purchased it from a member here a long time ago, but I'm hoping he may be able to shed some light. Of course it's possible that the lens is not mine, too. Just seems unlikely to me at this point. Maybe I should draw smiley faces on all my gear.

For reference, the recovered lens has serial 1001179 and my registration card says 10878001.

It's a shame that lens serial #'s aren't recorded in exif data. I hope it is yours and you can claim it.

Sorry for the OP in likely not getting his lens. There were four versions of that lens with differing finish on the outside surfaces. I not that the recovered lens has 7-digits while the OP's lens has 8-digits. That may mean a much 'later' lens.
EXIF information can already record the lens serial number if the lens info is passed to the camera body, which isn't the case except in recent lenses, and even then a Canon lens on a Canon body. A Sigma lens might not ever pass the necessary info to the body.

I was updating some paperwork and came across this thread. For anyone interested, the lens was not recovered as my paperwork did not match the suspect lens.