Panasonic S1R has a Leica L lens mount and currently there are 146 native lenses available for this mount.
The latest released lenses that are compatible with the S1R are the SG-image AF 35mm f2.2, the 7Artisans 135mm f1.8 L and the TTArtisan 50mm f1.8 NEO L.
S1R also has a sensor based image stabilization system that is up to 6.0-stops effective which means that all of these lenses will be stabilized when used on the S1R.
Since Panasonic S1R has a Full frame sensor, it has a focal length multiplier of 1x so lenses will provide their original focal length on S1R.
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Panasonic S1R Lenses with Image Stabilization
Panasonic S1R Lenses with Weather Sealings