File:HACS deflectionscreen in operation.jpg

English: This still from a WWII training film shows the HACS deflection screen operator in the foreground and the other HACS Table operators in the background. The solid line running diagonally through the centre of the ellipse shows the wire aligned with the aircraft's track of approximately 295 degrees; the Deflection Screen operator has his right hand on the Lateral Deflection Control which is aligning the vertical line with the point there the track wire crosses the edge of the ellipse, and he is also using his left hand to align the Vertical Deflection Control and a horizontal wire, (which cannot be seen) so that it also intersects the vertical wire at the edge of the ellipse. When the two wires are properly aligned at the point where the track wire meets the ellipse, the deflection angle is automatically fed to the guns.