Lumins

What's the diferense between max lumins and torch lumins

Correct me someone if I am wrong...but I dont think max lumens is anything really.

You can measure lumens different ways. At the emitter itself or OTF(out the front). OTF is a more realistic and accurate way to measure(I think). Once the light passes thru the lens you can typically lose about 30% of those emitter lumens.

Oh yeah...and I think torch lumens is OTF...again...I may be wrong.

:welcome:

joshth09 is right. OTF lumens is the light measured which is actually the light that you see. The OTF lumens are not equal to the lumens the LED is emitting because some light gets lost in the optics, reflector and lenses. Some companies write the OTF lumens in the description and some the lumens that the LED emits at the given current. So you have to be carefully when you are comparing flashlights just by using their descriptions.

rayman

When you hear max lumens in a certain context you can pretty well regard it as junk. Often they'll refer to max lumens when stating the theoretical maximum that the led can put out, as stated by the led's manufacturer. This is the case with the "900 lumen" P7 lights on DX. It does not even refer to emitter lumens, because it's unlikely the flashlight manufacturer is driving the led at the specific voltage and current required to get the "max" out of the led. Further, then will not have the proper heat syncing in place to remove the heat to maintain the lumens. Heat and lumens are inversely proportional.

You can pretty well make the following assumption 99% of the time:

torch (Out The Front) lumens < emitter lumens < "max" (theoretical) led lumens