How much lumen variation is normal and does it even matter?

There are a number of people here who have light meters and a bunch of very good reviews. I truly do appreciate all of that. However, sometimes I wonder how meaningful any of it is as things vary so much in the real world. Had some fun earlier this winter playing with some A2 lights and, despite not having a light meter, I know from power usage that my lights maintained a significantly higher output for much longer than the excellent charted reviews. That is simple to understand due to the huge temperature difference.

Other factors are much harder to quantify. Some batteries just don’t put out enough juice to hit the output targets. Some drivers change output dramatically as the charge goes down. (eg my TS10 can be noticeably brighter than my TS21 if the TS21 is at 3.5v and the TS10 is at 4.1)

Add to that the fact that it is difficult to perceive the difference between say 1000 and 1400 lumen etc. I know these measurements are helpful and I do appreciate the reviews and especially manufacturers that try to publish accurate numbers.

There is one review in particular that I do not understand. Am sure that Marco would have tested his battery and certainly it would have been as good as my somewhat older LADDA 2450. Perhaps he just got a dud. Perhaps the latest batch of E03H II is just better than the early model he reviewed. I don’t have a light meter and can’t actually quantify it but am certain that my new E03H II is noticeably brighter than his review would indicate. Testing it just against my eye comparing to a TS10, TS21, and an E02 II it sure appears to me to be much closer to the spec. Could not be as low as his test.

Just curious for those of you with light meters and multiples of lights. How much variation is normal? I just don’t believe that the SSt20 4000k is that much dimmer as the review would suggest. Not doubting that he gave honest numbers but also not believing that all of them are actually going to perform like that.

Interesting, if mostly academic, question. I once read a review, possibly on here, possibly CPF, where the reviewer (?Selfbuilt) had multiples of the same light and there was indeed output and runtime differences. I can’t remember the make/model of the light, perhaps it was L3 illumination L10?

Given likely variations between same lights, I suspect the manufacturer specs are the mean performance?

Higher priced brands (HDS, Surefire) probably minimum specs?