[. . . ] The lenses having CE marking on their bodies are conformity with the standards EN50130-4 and EN55022 related to EMC directives by EU. The flange back of the lens is factory adjusted for C mount or CS mount, respectively. [. . . ] In case images defocus during zooming operation, perform the following back focus adjustment referring to the Operating Instructions of the camera. Cover front of the lens with a ND filter according to the prevailing lighting conditions. ) Set the focus ring at [INFINITY] position and the zoom ring at [WIDE] position, and then adjust back focus of the camera. set the zoom ring at [TELE] position and make focus adjust by the focus ring. Repeat the procedures and until images maintain their focus throughout the zoom range. After reading this Operating Instructions, keep it for future reference. â· Keep the lens away from dust, poisonous gas, moisture and salt. When images are too dark, too bright or there is no image, make the adjustment according to the following table. LEVEL may not be lowered in some cases due to backlight compensation and AGC features of the camera being switched on. â· When the AGC of the camera is switched on, there are some instances where the level does not alter and the image quality deteriorates, even when the "LEVEL" adjustment variable resistor is turned all the way to "L" side. Turn the "LEVEL" variable resistor towards "H" until the image quality improves. Manual control of the iris can be achieved by applying a voltage of between DC1. [. . . ] Turn the "LEVEL" variable resistor towards "H" until the image quality improves. Manual control of the iris can be achieved by applying a voltage of between DC1. [. . . ]