A method of narrow-gap welding, the welding system, the welding part and device

In the method of narrow-gap welding using a welding electrode (10) in a narrow gap (15) an image (44) of the welding electrode (10) and / or of the arc and at least one wall (20, 25) of the Engspalts (15) is at least in part detected from the image (44), the distance of the welding electrode (10) of the wall (20, 25) of the Engspalts (15) is determined and made depending on the position of the welding electrode from the determined distance (10).