Tamron’s newly announced 17-28mm f/2.8 Di III RXD lens is designed for full-frame Sony mirrorless cameras, though, ats DIY Photography notes, you could use it with APS-C models too with a 25.5-42mm equivalent focal length. This is Tamron’s second zoom for the Sony E-mount, along with its popular 28-75mm f/2.8 …