Imamacuser
Veteran
I just got a Sigma 17-50mm 2.8 (Nikon mount), and it won't mount on my Nikon F to E-mount dumb adapter (Commlite CM-NF-NEX). All my Nikon AIS, D, & G series zooms and primes mount fine onto the adapter as well as my Nikon SLR; the same goes for my manual and AF Tokina lenses. It looks like the Sigma's mount protrudes too deep into the adapter to allow it to connect properly. Is this a compatibility issue, or do I have a bad copy lens or adapter?