The “airtight” technology allows energy savings but hinders direct process observation inside the vessel and information on the unmelted scrap volume and on possible skull formation at the furnace walls. To overcome this difficulty, a new concept is proposed, based on mounting a camera and an endoscope inside an existing burner. This technique has been first implemented on the 155 tons DC furnace in the PROFILARBED Esch-Belval plant. Typical images of the melting phase are presented. Scrap movement mechanisms in the burner produced cavity have been displayed in real time. Operational benefits combine the appraisal of scrap basket charging time and anticipation of abnormal melting behaviour.