This paper presents two versions of optical systems of telescopes to be simultaneously operated in several spectral regions. The optical system in the first version is a complex six-channel telescope for simultaneous daytime and nighttime observation in three spectral regions: the visible region and two IR regions. The optical system in the second version is a two-channel telescope for daytime observation that operates simultaneously in two spectral regions: the visible region and the far-IR region. The optical system of a reflective telescope for the visible region and the characteristics of the image quality are presented.