Mark Jongewaard started as an illumination engineer at Lighting Technologies, Inc. (LTI) in 1989, later becoming vice president, director of the optics division and part-owner until 2006, when LTI was sold to Musco Sports Lighting. Since the sale, Mark and business partner Ryan Kelley led the formation of LTI Optics (LTIO), which spun off from Musco and continues the optics related business from LTI. This includes the development and sale of Photopia — the most widely used optical design software in the architectural lighting industry — as well as providing optical design services for illumination based (non-imaging) optical systems. He currently is president and principal of LTIO.