Sony A1 has a Sony E lens mount and currently there are 219 native lenses available for this mount.
The latest released lenses that are compatible with the A1 are the Samyang 14mm F2.8, the Samyang 8mm F2.8 Fisheye and the Samyang 85mm F1.4.
A1 also has a sensor based image stabilization system that is up to 5.5-stops effective which means that all of these lenses will be stabilized when used on the A1.
Since Sony A1 has a Full frame sensor, it has a focal length multiplier of 1x so lenses will provide their original focal length on A1.
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Sony A1 Lenses with Image Stabilization
Sony A1 Lenses with Weather Sealings