With some slight exertion, you manage to push open the door to a dark lab with cluttered desk up against the wall and an obvious path worn into the marble checkered floor where the inhabitant has paced relentlessly. Going for the light switch, a layer of dust comes off onto your hand. When you turn on the lights they don't so much spring to life as metaphorically cough and gag awake. You decide to keep them off. A lantern on the most cluttered desk answers your question of the predominant light source, besides natural light. From it's light, you can tell this is an amateur's lab.