Sony SKU: SEL400F28GM | Helix SKU: SYSEL400F28GM
Sony's most advanced lens technologies have been unsparingly applied in this large-aperture super telephoto lens, achieving extraordinary speed, outstanding G Master resolution and bokeh, plus professional control and reliability. Moreover, the SEL400F28GM is the lightest super telephoto lens in its class2, providing unparalleled handheld shooting freedom.
New XD (extreme dynamic) Linear Motors deliver higher thrust than conventional types, achieving up to a 5x improvement3 in moving-subject tracking performance with current and future camera bodies. Two of these new motors and newly developed algorithms quietly drive the lens's large focus lens group faster and more precisely than ever before. The full speed performance of advanced camera bodies can be applied to capturing dynamic sports or wildlife subjects.
Extremely high design standards ensure outstanding resolution right out to the image edges. Three fluorite elements minimize chromatic aberration. Spherical aberration is carefully controlled during design and manufacture to achieve the highest possible bokeh quality. Optional high-performance 1.4x and 2.0x tele-converters are supported4, providing outstanding resolution and contrast even at 800 mm.
An innovative optical design that includes three fluorite elements reduces the number of elements at the front of the lens barrel for a low weight of 102.2 oz (2,895 g). Durable magnesium alloy components also contribute to reduced weight. Portability and handling are outstanding, and ideal balance affords agile, easy operation whether shooting handheld or on a monopod.
The dust- and moisture-resistant design5 provides the reliability needed for outdoor use in harsh conditions. A durable magnesium alloy used for the lens barrel exterior, tripod mount, and interior barrel components achieves tough durability while minimizing overall weight. The front lens element features a fluorine coating that helps to keep it clean while making it easier to wipe dirt and fingerprints away.
Full-time DMF allows manual focus to be engaged simply by rotating the focus ring, even while shooting in AF-C mode. Optical image stabilization is built in, and a new Mode 36setting features an advanced algorithm that provides optimum stabilization for dynamic sports action while also making framing easier. Four focus-hold buttons and a focus ring with Linear Response MF further enhance versatility.
G Master series lenses take imaging and expression to previously unattainable levels with a stunning blend of extremely high resolution and softly dissolving background bokeh
 Fluorite lens  ED glass
MTF (Modulation Transfer Function) describes how well a lens can reproduce fine details, measured as the degree of contrast achieved between finely spaced lines.
 Contrast (%)  Distance from optical center of lens (mm)  Max. aperture  F8 aperture  Spatial frequency  10 line pairs / mm  30 line pairs / mm  R: Radial values T: Tangential values