By day 48-year-old Craig Ellis is an associate professor of finance at a university, but in his spare time he goes over to the dark side by kitting up as a detail-perfect stormtrooper.

Since 2011, the self-professed "Star Wars tragic" has been a member of the 501st Legion, nicknamed Vader's Fist, a club of costume enthusiasts who enjoy dressing up as the villains of the film franchise.

Revesby resident and finance professor Craig Ellis takes a break in his stormtrooper outfit. Credit:Steven Siewert

Other Star Wars costume groups exist in NSW alongside the 501st Legion, including the Rebel Legion, who portray the good guys of George Lucas's cinematic universe, and the Galactic Academy, for cosplayers (short for costume players) aged under 18. The NSW-ACT branch of the 501st Legion, known as the Southern Cross Garrison, has 88 active members.

"Anyone can join just as a fan, but to be a full member you have to have a movie-accurate costume," Ellis says.