As part of the FE line of lenses, the FE 90mm f/2.8 GM is designed to cover the Sony a7-series cameras’ full-frame sensors. Since it’s an E-mount lens, it’s also fully compatible with APS-C NEX cameras. When used on a full-frame camera, this lens provides a true 1:1 macro ratio with a 90mm focal length. With an APS-C sensor camera, you’ll still get 1:1 macro reproduction, but the focal length is equivalent to 135mm. The fast f/2.8 aperture enables extremely shallow depth-of-field control at macro focus distances and the rounded nine-blade aperture diaphragm produces smooth out-of-focus highlights when you desire a shallow depth of field. The fast, highly accurate, and nearly silent autofocus performance, which is crucial for macro work, make this a great macro option at an affordable price. Like the rest of the lenses in this series, this lens is dust and moisture resistant, offering the ability to use in less than ideal settings.