check out this photo from google:
Mine, at f4.5, also looks like this.
if you click at the link to the site where this photo is published you arrive at a shop...( therefore I don't link directly
there are various photos of the lens, one shows that the lens is set at f4.5. I suppose that the aperture had not been changed for the different takes, and that the aperture seen, at the google pic, also is at f4.5.