Fenix LD01 with Q5 / XP-G R4 / XP-G R4?

Hi.



I'm planning to buy me a Fenix LD01.

I't s confusing to me that the lumens drop down from 85 tot 70-77 in the advertising I come across when the LED is evolving into something better I think/hope. In youtube I see clear difference in comparing the ned LED's with older ones. Is the lumen the same or less but the batterylife better on the new LED?



What should I choose? Q5 or R2 or XP-G R4 or XP-G R5 or something else?



Suggestions for a smilar or better keychainflashlight as an ECD that is even or even betterare welcome!

First:
Fenix used to "exagerate" their lumens rating a little bit (like many vendors).
Now they use a rather standardized measurement method. Thus the new lights, albeit with lower lumens rating, should be as bright or brighter than the old ones.

Second:
The newer LED generations have a better efficacy (efficiency) than the old ones, producing more light and/or for a longer time.
However there are other more subtle differences:
Many people got the impression that the highest class LEDs often have a less apealing light colour compared to older ones, probably because they are selected very agressively for highest output (and highest output only).
And there are LEDs with smaller dies which are easier to focus (resulting in better throw) than those with larger surfaces.

Hope that sums it up...

I don't think Fenix was purposely exaggerating their output, but just not measuring it the same as the new standard.
Many light makers would just measure the power of the light engine going to the LED and using the power delivered to the LED they would just look up the bin information and choose the top of the bin output and label that as the light output. This essentially is cheating because bins vary, the optics and lens reduce output more than just a tiny amount too. Some light makers do even worse they take the maximum output of the LED itself and label the light that output even though the driver isn't providing enough current to power the LED at that level at all. Some may take the power going into the driver and applying that to the bin charts for output when the driver and optics etc are not 100% efficient. Essentially some exaggerate, while others estimate and forget to account for losses. Another trick used to have a higher output is to ONLY measure the output immediately off a fresh battery when it is at the maximum. The new standard says wait a few minutes for the battery/light engine to stabilize before measuring. Some light drop perhaps 5-10% in just a few minutes as the battery caves under the current load and the LED itself heats up.

FWIW many have reported that the tint from the 'R2' version was better than the earlier 'Q5' and the latest XP-G version.