Elzetta Tactical Lighting’s Dave Barnett explains light measurement by candela in this video. He contrasts that with the measurement of lumens, which is another term you will see when buying a tactical flashlight. A little knowledge is power.
Dave is a solid guy and I have spoken to him many times at SHOT Show. Their products have thoughtful design features. We drove nails into a 2X4 with one of their Bravo models the first year I was at SHOT. The flashlight still threw a perfect beam afterward and we were not the only ones to have beaten that particular sample!
A viewing of both videos can give you a better understanding of how tactical flashlights can be compared to others. Since we can be called on to work in darkness during any shift, knowing how these tools really function can give you an advantage out on the street.