I had a feeling that was the case.  I've seen probably a few hundred concept images of craft from Halo, all done by fans.

---

Finis Coronat Opus! - "The End Crowns the Work!"

"Seek freedom and you shall be enslaved by your desires. Seek discipline and there you shall find your liberty." - Bene Gesserit Precept, Chapterhouse: Dune