Double‑image rangefinders have linear graduation with divisions of 1 or 2 cm. As the distance increases, the image of the strokes of the staff scale decreases, becoming unclear. On this basis, the maximum distances for measurement should not exceed 200‑250 m. To eliminate this disadvantage, the factory "Carl Zeiss" (GDR) has created a precision double‑image rangefinder as an attachment to the Theo 030 (Theo 020) theodolite, using the method of logarithmic tacheometry, proposed in 1878 by Tichy. ...