Originally Posted by
Drew Eckhardt
Mathematically you're not going to make a meaningful conversion because lux is light per unit area, lumens is the total light, and you can't factor in beam shape - the light ending up on trees and in the air doesn't count for illuminating the road.
Subjectively it looks as bright as a Magicshine MJ808 on medium which is a claimed 900-1000 lumen light that really measures 550-650 on high and is probably 275-325 on medium with twice the run time, but you can see better with the B&M because it doesn't have a significant hotspot interfering with your night vision.
You can't tell absolute brightness from images due to cameras seeing differently than people with varying exposure times, just what the beam is shaped like. To borrow @
PaulRivers picture from his 2014 bikeforums.net thread
http://www.bikeforums.net/commuting/942351-ixon-iq-premium-bike-light-may-best-bike-light-i-ve-ever-seen-lumotec-cyo-google-page-ranking.html
Magicshine MJ-808 P7 10W LED lamp (for MTB use) compares an Edelux dynamo light measuring 180 lumen @ 30km/H to the Magicshine, although the Ixon IQ Premium shares the Edelux II optics which are 30% brighter than the original
MagicShine is nothing more than a generic Chinese light you can get on either E-bay or Amazon all day long for $45 to $65 that was "branded" with a decal. Save the $150 or so of the cost of a MagicShine and get the generic versions for a lot less money.
The generic lights, like MagicShine, only put out roughly 50% of the rated lumens that the Chinese manufacture claimed, but even so if you buy a 2000 lumen generic light and only get 1000 lumens for $45 or so, that's still a good deal, however some of the shortfalls that plagued earlier models were batteries getting so hot either they caught fire or whatever it was in contact with caught fire, but I think the newer generic lights have fixed that issue but don't quote me on that.