Leica APO-Vario-Elmarit-SL 90-280mm f/2.8-4
The zoom range of the fast Leica APO-Vario-Elmarit-SL 90–280 f/2.8–4 lens 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 280mm.
The newly developed dual internal focusing (DSD®) concept enables a fast autofocus. Its optical image stabilization (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.
Of the 23 elements in seven moving groups, seven are made from glasses with anomalous partial dispersion for the minimization of chromatic aberrations. The movement of the two focusing elements is provided by a newly developed drive concept with linear positioning of the lenses by stepping motors. A special feature of this is that the overall length of the lens does not change when either focusing or zooming.