You can see the sun at two different positions. Ghosting changes with the position of the sun. Sometimes even the shape of the sun star depends a little bit on the position of the sun. Zoom lenses were tested at 20 mm.
Specifications: Canon EOS 3 or Pentax MZ-M, Fuji Sensia 100, f/16, 1/160 s.

The digital images show the crop of a APS-C sensor with a crop factor 1,6. For comparison the 36 mm x 24 mm full frame is shown.

As you can see it is easier to get a nice sun star on film than on the chip of a digital camera.
Specifications: Canon EOS 20D, f/16, 1/125 s left, 1/250 s right.

Stefan Bar. from Hamburg kindly provided me a digital image of the star of the Sigma EX 3.5-4.5/15-30. Although light sources and apertures are different (f/9 instead of f/16) it is obviouse that the star is similar to the one of the Sigma EX 4.5-5.6/12-24. In both cases the rays diverge as they extend away from the light source. But due to its 8 aperture blades the star of the Sigma EX 3.5-4.5/15-30 has got two rays more.

This is one of my first tests. Note that the sun is not in the same position on all the images. So you can not compare ghosting directly.
Spezifications: Canon EOS 3 or Pentax MZ-M, Fuji Sensia 100, f/16, 1/160 s.