Point me to some info.


Newly Enlightened
Jun 13, 2008
I noticed that my mercury vapor security light is rated at 175w & 5700 lumen. How is this light output number derived as compared to say a 190 lumen flashlight? Does the huge difference have to do with the fact that the security light emits light in all directions & the flashlight in a focused beam, or is the MV light just that much brighter? Please link me to any info you know that may "shed some light" on this.


Mar 26, 2010
Raw lumens is generally much more important than beam profile, at least in general use.

I've heard that 2x lumens only appears 50% brighter, and it would take 4x lumens for the beam to appear twice as bright to our eyes.

So you need a light that outputs 800 lumens for it to appear twice as bright as a 200 lumen light.

Since you get such small returns appearance wise, a floody 700 lumens light would appear to be much brighter than say, the DEFT FTP at close to mid range. At long range the DEFT will start to outshine the floodlight, but my opinion is that the average person has little use for throwers.

It's one reason why my Malkoff M60 drop-in disappointed me when compared to my Nailbender SST-50. The M60 should have a tighter beam and throw farther, but the SST-50 simply appears brighter because of the raw lumens.


Dec 18, 2006
Bay Area, CA
The huge difference in output has nothing to do with beam pattern. It is the actual difference in output between the security light and the flashlight.

Lumen, and lux are two separate things. Lumen is total output, whether that is a pencil beam or a 360 degree flood.

Lux is how far the light projects, and that has to do with the beam pattern. A well focused 190 lumen flashlight should be able to out throw your 5700 lumen security light, but the security light still has much more lumen output.

Our eyes are also deceiving when it comes to comparing light. A slightly dimmer light with a more focused beam can appear brighter then a slightly brighter light with a more diffused beam.