Here the whole of the left lung has collapsed. Compare the first image to the second radiograph of the same patient where there is only left upper lobe collapse. There is loss of the silhouettes of all the border forming structures on the left. There is clear volume loss with a raised hemidiaphragm (indicated by the position of the gastric air bubble), rib crowding and mediastinal shift. If you look carefully, you can see the obstructing lesion blocking the left main bronchus. Refer to the article Patterns of lobar collapse for more information.