A camera arrangement includes a camera, a light source, and a light-guide which are in an inside region separated from an outside region by a window. A pair of casting pool confinement plates are thrust against the ends of rolls by thrusters mounted with the side plastes on carriages forming part of moveable structures which are connected to the outer rends of nozzle pieces by pins and which can be moved by operation of screw jacks. At the distal end the extractor includes a plurality of wires with each wire comprising a first portion having an individual strand and a second portion comprising a plurality of filaments. If that is so, the program computes a maximum permitted frame rate and an integration time of the pixels of the camera. After purging the second reactant, the third reactant for removing impurities and improving the stoichiometry of the thin film is injected and purged.