5 aspherical of which 2 extreme, 2 extra low dispersion
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This is the best 16-35 zoom ever made for full-frame Sony cameras, and it's also the biggest and most expensive. The Zeiss 16-35/4 OSS is as good optically and is smaller and costs less, but it's a stop slower in trade for its optical stabilization. The Zeiss is a good choice for hand-held nature, interiors and landscapes, while this f/2.8 lens is better for physical durability, news, sports and action — or shot on a tripod where stabilization is of no help.