Sigma released new firmware for 11 lenses all at once, all L-Mount varieties of nine prime lenses, plus the two L-mount standard zoom models.
The firmware adds one particular feature across the board: the ability to choose linear or non-linear focus control using the lens focus ring. This makes the lenses more compatible with automated focus pulling rigs, an itch that video shooters in particular often wish to scratch.
Many of the lenses also addressed individual lens bugs and fixes for particular cameras, where new body introductions revealed new issues. The Leica SL2 features prominently in the fixes, having introduced some shutter lag somewhere in the firmware chain for some lenses.
The new focus ring feature applies only to some L-Mount camera bodies, including Sigma’s on FP range; the Lumix S series; and the Leica SL2 series.