I use a wide angle lens to take listing photos with (Canon 10-22mm) and my interior photos tend to have dark edges when the room isn't overly bright because the flash isn't wide angle.

The camera store tried to sell me a light kit (but I'm not excited about the prospect of dragging around a house two tripods of lights and extension cords into every room).

Are there any other agents who uses wide angle that has a solution for this?