Author Topic: Usable lumens vs. usable lux: Exposure Diablo vs B+M Luxos U IQ2  (Read 1268 times)

Usable lumens vs. usable lux: Exposure Diablo vs B+M Luxos U IQ2
« on: February 27, 2019, 03:26:13 pm »
I'm pretty certain about this statement. 

An Exposure Diablo at 1800 lumens produces the same amount of usable illumination of the road surface as a B+M Luxos U IQ2 at 90 Lux (that is at high beam; normal beam is 70 Lux).

Note 1: 50 year old eyes.
Note 2: Diablo helmet mounted.  If stem mounted the near illumination / reflection off road makes the Diablo less effective than the Luxos.

Re: Usable lumens vs. usable lux: Exposure Diablo vs B+M Luxos U IQ2
« Reply #1 on: February 27, 2019, 08:41:47 pm »
Lux is affected by beam shaping and focus, so bears no relation to lumens unless the optics are the same and only the source differs.  IME lux isn't always a good measure either; my supposedly 80 lux Ixon IQ Premium is nowhere near as bright as my supposedly 100 lux dynamo IQ-X.  Similar (not identical) optics.   There's a lot of marketing fudge going on.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

DaT

Re: Usable lumens vs. usable lux: Exposure Diablo vs B+M Luxos U IQ2
« Reply #2 on: February 27, 2019, 09:10:53 pm »
I'm pretty certain about this statement. 

An Exposure Diablo at 1800 lumens produces the same amount of usable illumination of the road surface as a B+M Luxos U IQ2 at 90 Lux (that is at high beam; normal beam is 70 Lux).

Note 1: 50 year old eyes.
Note 2: Diablo helmet mounted.  If stem mounted the near illumination / reflection off road makes the Diablo less effective than the Luxos.
I've just bought an Exposure Strada SB (1500 lumens) and have been using a Ravemen PR1200 (1200 lumens) for the past year. In the past I have also used an Edelux II (90lux) and an IQ-X (100lux).

The Ravemen beats both the dynamo lights and the Exposure strada beats the ravemen by quite a bit (only tried for 30mins tonight so I'll my thoughts may change).

All the above lights are designed for road use and all are light enough to descend at any speed I fancy in pitch black.