Founded by Igor after a three-year collaboration with the University of Rochester’s Institute of Optics, Cassi makes do-it-yourself telescope kits that turn building a telescope into a hands-on introduction to astronomy. The kit is designed for families and beginners, pairing assembly with guidance on optics, stargazing, and space imaging. Its mission is to spark interest in astronomy and STEM through shared projects.
Rayleigh Optical CorporationSince 1987, co-founders Vilma and David Anderson have operated Rayleigh Optical Corporation as a worldwide fabricator of large custom precision optics. The Hanover, Maryland, company specializes in spherical and aspherical components from 0.25 to 1.5 meters, with its mirrors and lenses used at premier astronomical sites including Pan-STARRS and the Dark Energy Survey Instrument. It also extends its shop and expertise to amateur telescope makers through its planned Center for Amateur Optics and Telescope Making.HALETHORPE, MD
Optical Guidance SystemsNow in its 31st year, Optical Guidance Systems is an owner-led Pennsylvania company known for bringing the Ritchey-Chrétien telescope line to broad worldwide acceptance. It builds research-grade observatory systems for institutions such as universities, government agencies, NASA and ESA, with custom instruments shaped around demanding research needs.HUNTINGDON VALLEY, PA
Tele Vue Optics, IncFounded by Al Nagler in 1980, Tele Vue Optics designs and produces telescopes and precision eyepieces for astronomical and terrestrial viewing. The Chester, New York, company is known for optical lines such as Nagler and Ethos, while its birding scopes are built in the USA and tested for high-power observation. Many Tele Vue designs remain in production for decades, reflecting a deliberately long-lived approach to optical equipment.CHESTER, NY