Reflecting telescopes capture light using a mirror while refracting telescopes capture light with a lens. The advantages of reflecting telescopes are: 1) they collect light with a mirror so there is no color fringing, and 2) since a mirror can be supported at the back there is no size limit. In an effort to alleviate the problem of color fringing always associated with lenses, Isaac Newton built a reflecting telescope in 1668 that collected light with mirrors.