The zoom range of the fast APO-Vario-Elmarit-SL 90–280 f/2.8–4 follows on directly from that of the Vario-Elmarit-SL 24–90 f/2.8–4 ASPH. Together, these two lenses cover a full range of focal lengths extending from 24 to 280 mm.

The newly developed dual internal focusing (DSD®) concept enables a fast autofocus. Its optical image stabilisation (OIS) compensates for up to 3.5 stops of camera shake.

The autofocus system shared by these lenses is fast, precise, and nearly silent. Their outstanding AF performance figures are thanks to the autofocus drive unit they both utilize. These are limited only by the mass of the glass elements moved when focusing; the speed of moving from infinity to the closest focusing distance. In order to preserve the compact dimensions of the lenses, the integration of these components must be perfectly optimized within all design constraints.

Specialists from the areas of optical engineering, mechanical engineering and electronics worked together as an interdisciplinary team on the development of a unique lens concept based on double internal focusing. This system, comprising two especially light focusing lenses, allows the construction of particularly small and compact drive systems. While being able to work within tight space constraints, the drive motors used must maintain peak performance in all situations to be chosen for such a cutting-edge camera system.

Several contrast measurements at various focusing positions must be made before the correct direction for focusing can be determined and followed by precise focusing. In this procedure, the focusing lens elements must be moved rapidly in accordance with the speed specifications of the contrast AF system. This requires a dynamic drive system without any room for error.

In these lenses, the drive units installed are extremely powerful and robust stepping motors with Dual Syncro Drive™. Thanks to these, the entire focusing range can be traveled completely in fractions of a second. This means that the lenses achieve values that are among the best in the full-frame system segment in terms of speed, precision, and operating noise.