(written from a Production point of view)
Mark A. Stetson (born 1952), a 1978 graduate from the Art Center College of Design in Pasadena, California (as was his fellow Magicam co-worker Chris Ross, and which also counts William Ware Theiss and Andrew Probert among their alumni), was a model maker who worked from May 1978 through November 1979 on Star Trek: The Motion Picture while employed by three consecutive companies: STOIC (Paramount Pictures), Astra Image (Robert Abel & Associates), and Magicam, Inc., constructing, detailing, finishing, and maintaining the various miniatures for the production.  In his first professional employment after graduating, he has worked among others on the workbee model and has constructed the small refit-Constitution-class shuttlebay maquette.
After his tenure at Magicam, Stetson continued his career as visual effects staffer in the motion picture business, having worked for a variety of companies as model maker and model shop supervisor on productions like Blade Runner (1982, with Ross, supervised by Douglas Trumbull and Richard Yuricich, and for which he was recommended by Gregory Jein), Brainstorm (1983, again with Douglass Trumbull), Ghost Busters (1984), The Adventures of Buckaroo Banzai Across the 8th Dimension (1984 with several other Trek alumni including Gregory Jein, Denise Okuda, Christopher Lloyd, and Robert Ito, among others), Total Recall (1990), and True Lies (1994). During this period Stetson worked as an independent contractor, operating his own company which was in existence from January 1980 through February 1995, first as Stetson Visual Services, and from January 1989 onward as Stetson Visual Services, Inc..
After 1995, he has worked for several studios, mostly as visual effects supervisor and has been the recipient of various award nominations, among others three Academy Award nominations in the Visual Effects category for 2010 (1984), The Lord of the Rings: The Fellowship of the Ring (2001), and Superman Returns (2006); the second one he won, sharing it with, among others, Jim Rygiel. In his acceptance speech, Stetson acknowledged Magicam's Jim Dow, mentioning The Motion Picture, for giving him his first professional job, as well as acknowledging Jein and Trumbull. 
In 2010, Stetson was hired as Creative Director/Visual Effects Supervisor - Feature Films at ZOIC Studios, a position he currently still holds.