Sony SEL90M28G Manual page 11

Precise, quiet focus for stills and movies
Two focus groups in a floating focus configuration are driven by an innovative DDSSM (Direct
Drive Super Sonic wave Motor) system for smooth, precise positioning of the relatively heavy
lenses that make full-frame macro magnification possible. This system is remarkably quiet, and
is ideal for animal or insect photography as well as movies.
Sharp and clear without a tripod
Although a tripod is usually considered necessary for sharp macro photography, built-in OSS
(Optical SteadyShot™) image stabilisation makes it possible to shoot sharp macro images
handheld. The heavy stabilisation lens is driven by a responsive linear motor for fast, precise
stabilisation.