Making sense of flashlight brightness...?

Question

I got confused when trying to buy a flashlight today.
When the flashlight says 3 Watts, is that the same wattage output than a light bulb in my house? 3Watts seems very low to me, yet it was the highest wattage I could find.
How does a lumen compare to a watt?
How does a candlepower compare to watt?
Do volts have anything to do with brightness output? Some flashlights only say how many volts.
Some flashlights only say how many LED's it has, is there any way of telling how bright it is?

How am I supposed to compare if every company uses a different method of measuring light? WHY are there all these different measurements for light now? What was wrong with sticking to watts?

Answer 1

Lumens or candlepower is the true light you get out of a bulb or other light source. Watts is the power consumed to produce that light. Incandescent bulbs are very inefficient in this respect. Krypton and other rare gas bulbs are somewhat more efficient. LED's are the most efficient. With flashlights or any battery powered light the watts used are important because you have limited power in your batteries. So I disagree partially with Ynot. Watts are important but you really need to know the about of light you are getting from those watts.

Answer 2

Nothings wrong with sticking to Watts, and I think you should do. The Watt is a unit of power, so it relates to battery life and electricity consumption, whereas candlepower and lumen are units of light intensity. These are less useful and much more difficult to understand for a layman.

A typical flashlight will be 2 or 3 Watts, compared to a household light bulb which will more likely be 40 to 120 Watts.
The difference is that the light from the flashlight is concentrated in a small beam only needing to shed its light over a small area, but the light bulb scatters its light throughout the whole room so it needs far more power to light the whole of the rooms surface area.
Another difference is that the human eye quickly adjusts to changes in lighting levels so when we use a flashlight in the dark our eyes become more sensitive and give us the impression that the flashlight is giving out more light than it really is.

So I suggest you stick to Watts, unless you want to be a lighting engineer or a lighthouse keeper.

Answer 3

For brightness, watts do not affect my decision. Some of the newest LED flashlights use MUCH less power than a regular bulb, and give of very bright light. The amount of current drawn is far less than a regular bulb type flashlight!!! For instance, take a regular bulb small flashlight against a small LED type flashlight. Turn them on.. The 'bulb' type flashlight will go dim or dead in a few hours or less!! Typical LED small lights will last for days.!! So, you won't only get brighter light, you will get far better battery life. (And don't use rechargeable batteries. They are usually 1.2 or 1.3 volts. I like a real 1.5 volt alkaline like a duracell...brighter.)!!

Answer 4

When it comes to flash lights, the intended usage is the more important issue. I have a small one that has a flexible shaft coming out of the cylinder, for the bulb and a laser in the cylinder. It is powered by 3 watch type batteries and clips in the belt pouch that I carry my Leathermen tools and a small magnifying glass in. It is about 3" in length at the base part and about 6"s over all. That is 4 1/2 volts powering a small grain of wheat type bulb, so it works out quite well in the type of work I do. On the other hand, you can get flash lights that use 3 D cells and can double for a club.

Answer 5

Military Grade Tactical Flashlight - http://FlashLight.uzaev.com/?xnoN