Nikon, Sony, Panasonic & Pentax all zoom in the same direction and opposite to Canon and Olympus. Sigma & Tamron lenses in Nikon mount zoom in the same direction as Nikon; don't know about other mounts. Focus, aperture and lens mounts also vary in direction. Since I used Pentax and Nikon cameras for 40 years before using Olympus µ4/3 cameras, their zoom direction still feels backwards after 4 years. When given the choice I buy Panasonic zooms. I'm even thinking of replacing my 12-40/2.8 Olympus with the new Panasonic 12-60/2.8-4 even though the Olympus have excellent optics.