[Review] Olight Perun 2 - 21700 Cool White 2500 Lumens Proximity Sensor Headlamp

[rookiedaddy]

@71k5

I appreciate how Olight is so accurate with their lumen outputs. But I’m curious as to why they are so inaccurate about what lumen level the light steps down to, from turbo.

I have seen this on many of their lights.

Accurate lumen levels, but totally wrong on the step down lumen levels.

And in almost every instance, the actual step down lumen level is higher than what is documented.

The difference could be attributed to several factors/variables:

• Light measurement Setup: For yours truly, I use a home-made light-box setup that I calibrated to several reference lights, so there will be variant in the measurement.
• Test Environment: Temperature plays an important part in these measurement. It impacts both the brightness and runtime.
• LED/Driver: Variance in LED batch and/or Driver during manufacturing and assembling process. Most mass manufacturers do not calibrate/fine-tuned the output like those from HDS Systems and some custom makers. Sometimes, a change in a tiny component due to sourcing issue could have great impact on how the light performs.
• The manufacturer took the lowest common denominator in their test result to publish.
• The manufacturer use Calculated figures. This is especially apparent in the lower brightness runtime.
• Miscommunications between R&D or Engineering Department and the folks at Marketing and/or Sales Department.
• etc.

There are also instances that the manufacturer over-quoted their numbers and corrected in a later revision and/or printing... it's a heavy heartache experience trying to convince the Engineer to correctly interpret the parameters in ANSI/NEMA FL-1 or ANSI/PLATO FL-1.