How would you go about solving a problem involving a lens moving at relativistic speeds, or an object being relativistic being viewed through a lens? instead of coming up with a specific problem, does anyone know what happens to lens' focal length and such as its velocity becomes large? not so much as a limit, but in general. i would assume its focal length increases in both converging and diverging lenses, but by what factor? does it simply change by gamma? any help appreciated.