Dark rooms do not need more light. They need light in three places

What we specify when a client says the room feels gloomy, and why the ceiling fitting is almost never the answer.
The three measurements we ask for, and why the fourth is optional

Wall lengths, ceiling height and the one window you keep forgetting. The fourth is the door swing, and it only matters in a room under 120 square feet.
Photograph the room from four corners, not from the door

Why the shot everyone sends is the one we can use least, the four we actually need, and how to take them on a phone without a wide lens.