Brightness should be measured in Lumens (lm) rather than Watts. For general camping, 200-500 lumens is sufficient, while search-and-rescue or industrial inspection requires 1000+ lumens. Pay attention to the Beam Distance and Beam Angle (floodlight vs. spotlight). For photography or medical use, a High Color Rendering Index (CRI > 90) is critical to ensure colors appear natural. Additionally, look for stepless dimming or multiple mode settings (High, Medium, Low, SOS) to manage power consumption effectively.