Kidger Optics has sold its Sigma optical software product line to Focus Software Inc. in Tucson, Ariz. According to Focus Software President Ken Moore, Kidger Optics has sold the copyright, source code and customer base related to its main product line, which is used in the design of a variety of optical systems from telescopes and cameras to infrared missile seekers and relay optics. The best of both Focus Software has its own optical design software, Zemax, which is similar but not identical to Sigma. "We will study the Sigma program over the next six months to look for its strengths," Moore said, indicating that his company wants to develop a future version of Zemax that "is a complete superset of all the best features of both programs." Terms of the sale were undisclosed, but Kidger Optics Managing Director Tina Kidger said, "I am delighted with the sale to Focus Software. I chose to sell the copyright because I think they'll do a marvelous job in carrying this forward." Customer support was one of Kidger's chief concerns regarding the sale of the Sigma program. Moore promises to honor all existing contracts with Sigma customers and to provide support over the next three years from its offices in Tucson, Japan and the UK under the same terms offered by Kidger Optics. Most Sigma users will have the opportunity to convert to Zemax. "I have every confidence that our customers will be taken care of," Kidger said. Her husband and company president, Michael Kidger, guided the evolution of Sigma software until his death Feb. 1. The optical design software business is a small but robust niche that has been growing steadily, finding wider application as the power of the personal computer has increased and package costs have come down. Douglas Sinclair, president, of Sinclair Optics Inc. in Fairport, N.Y., said he doesn't see the Sigma sale leading to consolidation in the optics software business. "I don't think that it changes things too much," Sinclair said.