Olympus E-620 has a Four Thirds lens mount and currently there are 47 native lenses available for this mount.
The latest released lenses that are compatible with the E-620 are the Venus 33mm F0.95 CF APO, the Samyang 135mm F2.0 ED UMC and the Samyang 300mm f6.3.
E-620 also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on the E-620.
Since Olympus E-620 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 E-620.
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Olympus E-620 Lenses with Image Stabilization
Olympus E-620 Lenses with Weather Sealings