Panasonic GF8 has a Micro Four Thirds lens mount and currently there are 123 native lenses available for this mount.
The latest released lenses that are compatible with the GF8 are the Rokinon 7.5mm f3.5 Fisheye, the Samyang 7.5mm F3.5 Fisheye MFT and the Panasonic 100-400mm F4.0-6.3 II.
Panasonic GF8 doesn't have a sensor based image stabilization system but 36 of these lenses already comes with optical image stabilization.
Since Panasonic GF8 has a Four Thirds sensor, it has a focal length multiplier of 2× so you have to multiply lenses original focal length with this multiplier to find the Full Frame equivalent focal length of the lens when mounted on GF8.
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Panasonic GF8 Lenses with Image Stabilization
Panasonic GF8 Lenses with Weather Sealings