Lens mounting issue

[BMoon1]

I recently purchased a used Sigma 160-600 km DG OS lens for my Canon Rebel T2i.  It stated is was for a Canon but when I went to attach the lens to the camera body, I noticed the mount on the lens is of considerably smaller diameter than my Canon 18-55 mm land my 75-300 mm and it will not mount properly.  My camera is an EF mount and my Sigma lens is listed as the same.  Do I need an adapter?  None of the research I did prior to purchasing this lens indicated I'd need an adapter.  Thanks for any help anyone can provide.

[Tronhard]

Welcome to the forum:

Sorry to learn you are having challenges! 

Any Sigma lens that is made for Canon's EF mount should fit your rebel T2i.  I assume you actually mean the Sigma 150-600 DG OS lens instead of 160-600 🙂  If you say that it is considerably smaller, I would strongly suggest you check that what you received IS an EF mount lens.  It sounds more like one for a Nikon mount, which is smaller.   If you look at the rear lens cap, it should say Sigma for Canon on the plastic

Is this a new lens or a used one?

[BMoon1]

Trevor,

Thanks for your speedy reply.  Minutes after posting, I noticed the rear cap and it does, indeed, say "For Nikon".  I purchased this used off of Ebay and went back to check the sellers post and it clearly states " for Canon", so needless to say, I'm not very happy at the moment.  Could be an honest mistake but I will be contacting the seller ASAP.

Thanks, again.

[Tronhard]

Very wise, hopefully they have a high trust rating.

If this resolves your issue from our point of view, can you please mark as resolved so others will not post and try to resolve the issue.