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Do you believe the lumen specifications from various flashlight manufacturers? Do company's like Surefire, UK, and Pelican have more realistic specifications concerning Lumens out the front of their lights? lovecpf
Do you believe the lumen specifications from various flashlight manufacturers? Do company's like Surefire, UK, and Pelican have more realistic specifications concerning Lumens out the front of their lights? lovecpf
Lets just put it this way... One of the guys at a bar I work security had, I think, a Ultrafire from DX that had 900 lumens engraved on the host.... we did a quick comparision on the ground with my LED Lenser M7R... 220 lumens... The M7R was almost 4 times brighter....His reasoning, "yours is more focused"....
He was correct. You two were comparing lux (the concentration of light) not lumens (the total amount of light).
Surefire is the only mfr I know that tests the output of their lights with an IS and rates them at the minimum guaranteed output at steady state conditions (i.e. thermal situations have steadied out). All other mfrs rate based on either calculated LED lumens by the LED mfr at the drive level predicted in the light mfr's circuit design or the max capable LED lumens (usually the lower end brands). Some state the OTF lumens gathered from independent tests (mostly by CPFers), but only state the transient initial output which is always higher than steady state.
There also seems to be some discrepancy these days about how much light is lost from LED to "out-the-front" between current ideas (20-25%) and ideas from a few years back (30-35%). The designs of the optics haven't changed that much in that time, and we had UCLs back then too and did testing with those as well and lumens lost were always about 35%. Now, the figures seem to be different. I think it may be due more to some mfrs driving the LEDs harder than they advertise or predict, resulting in people thinking there is less loss.
Regardless, take the output ratings of any mfr (aside from SF) with a grain of salt. Do enough research and you'll have a pretty good idea of what claimed outputs sound reasonable and which ones are rediculous.
Surefire is the only mfr I know that tests the output of their lights with an IS and rates them at the minimum guaranteed output at steady state conditions (i.e. thermal situations have steadied out). All other mfrs rate based on either calculated LED lumens by the LED mfr at the drive level predicted in the light mfr's circuit design or the max capable LED lumens (usually the lower end brands). Some state the OTF lumens gathered from independent tests (mostly by CPFers), but only state the transient initial output which is always higher than steady state.
There also seems to be some discrepancy these days about how much light is lost from LED to "out-the-front" between current ideas (20-25%) and ideas from a few years back (30-35%). The designs of the optics haven't changed that much in that time, and we had UCLs back then too and did testing with those as well and lumens lost were always about 35%. Now, the figures seem to be different. I think it may be due more to some mfrs driving the LEDs harder than they advertise or predict, resulting in people thinking there is less loss.
Regardless, take the output ratings of any mfr (aside from SF) with a grain of salt. Do enough research and you'll have a pretty good idea of what claimed outputs sound reasonable and which ones are rediculous.
Lumens accuracy among flashlight manufacturers
I would argue that Streamlight is pretty accurate with the graphs they provide for many of their products as well.
Lets just put it this way... One of the guys at a bar I work security had, I think, a Ultrafire from DX that had 900 lumens engraved on the host.... we did a quick comparision on the ground with my LED Lenser M7R... 220 lumens... The M7R was almost 4 times brighter....His reasoning, "yours is more focused"....
Never said he wasn't correct.... Just surprised because I never really compared a whole lot of lights like you guys....Im pretty sure he had Ultrafire WF-501B SSC P7... I know we're talking aspheric vs non aspheric...But I was just surprised that an aspheric 220 lumen light was alot brighter compared to a non-aspheric 900 lumen light... His didn't even look any brighter than my LED Stinger 160 lumens which is non-aspheric, but then again that spot is pretty tight as well
This sounds very similar to the claims made by some Home Entertainment manufacturers over the decades stating outrageous wattages put out by Hi Fi Systems.
These figures are up to 10 x what the real figure is.
I have been an Electrician and Electronics Hobbyist for decades and the real measure of output wattage of amplifiers in Hi Fi equipment is measured in RMS (root mean square) watts.
I think the lumens charade is really pushed over the top by some shonky (untrustworthy) manufacturers and retail outlets especially via the Internet.
A claim of 200W output of a small stereo system can include all four or five channels at PEAK measurements easily resulting in only 20W RMS.
It is like saying an old car that can only really do 60 MPH in reality can do 300 MPH.
What they don't tell you is when they measured the 300 MPH it was falling off a very big cliff!!
I know the last sentence is a bit extreme, but you get my drift. :devil: