Abstract: A mirror diagonal made with reduced material to achieve the same reflection effect is manufactured by (a) preparing an extruded aluminum tube having a bottom and two slant faces; (b) cutting the extruded aluminum tube to provide a plurality of short sections having a desired length and two open lateral sides, so that each short section forms a housing for the mirror diagonal; (c) processing each housing in predetermined manners; (d) adhering a reflection mirror to the bottom in each housing; (e) sealing the two open lateral sides of each housing with two sealing covers; and (f) mounting first and second tubes in two tube mounting holes separately provided on the two slant faces of each housing.

Abstract: A telescope includes a main tube having an objective lens and an eyepiece, and a focuser located between the objective lens and the eyepiece; a mode switching mechanism located in front of the eyepiece and including an external switch lever and an internal flip mirror fixedly connected to the switch lever; a digital image store device located behind the main tube for receiving and processing incoming video and audio signals, storing the processed signals on a memory, and displaying the video signals on a liquid crystal display; and a focusing control device located between the main tube and the digital image store device. By operating the switch lever, optical axes of the telescope and the digital image store device can be brought to parallel with each other for the digital image store device to receive and record images exactly the same as those being viewed with the telescope.