Venus Optics Laowa 14mm F4 is available in RF mount. It is a manual focus lens. It has very little distortion or CA or vignetting. Laowa 14mm F4 lens review below

Pros:

1. Sharp lens

2. Very little distortion

3. Very little to no chromatic aberrations

4. 52mm Polarizing filter can be attached

5. All metal well built lens

6. A real manual aperture dial

7. Compact. Bring the fun back into photography

Things to keep in mind:

1. It is a manual lens and while for such wide angle, the depth of field is deep, critical manual focus is still required. While not difficult, it is something to keep in mind