On 12/3/2017 5:21 PM, Tim McNamara wrote:
On Sun, 3 Dec 2017 16:56:24 -0800, sms
wrote:
On 12/3/2017 4:28 PM, Oculus Lights wrote:
On Tuesday, November 21, 2017 at 2:34:34 PM UTC-8, James wrote:
https://www.bike24.com/p2144878.html

-- JS

Is there a power rating? 100 lux at 10 meters, as the STVZO test
requires, is exceedingly bright. I'm hesitant to state they "must"
be drawing at least so much power, but my gut feeling is that its in
a range that a single LED can't handle. Anyone can rate a light
without stating the distance. My single LED 325 lumen measures 33
lux at 10, 500+ lumen measures 50 lux, and the best of the others on
the market, such as Supernova's 205 lm that's standard equipment on
many e-bikes, measure 25 lux at 10 meters, at most.

It's not all that new, and it's not very well rated. The complaints I
saw are a) the beam shape is too narrow, and b) the standlight is
inadequate. Neither is surprising. Dynamo lights make trade-offs, and
one major one is concentrating the limited available output into a
narrow beam, which is a big compromise in terms of safety, both in
seeing and being seen. The second is that the standlight is
necessarily fairly weak because the internal battery or super-cap
can't provide enough power.

The only suitable dynamo light for use in the U.S., in a dynamo-only
configuration, remains the Supernova E3 Triple 2. It has a proper
beam, and is not StVZO compliant for on-road use in countries where
StVZO compliance is mandatory.

Have you even looked at beam pictures?

Yes. The criticism was valid.

Here is what the review stated:

"The beam is too narrow

In focussing all the output from the LED directly ahead to hit that
magical 100 lux figure, B&M have made something akin to a laser… If it’s
outside a narrow degree arc from the front, it’s going to be near invisible.

Two examples. Take a standard lane-in-each-direction road, in complete
darkness. If you’re cycling in the centre of the left-hand lane with the
IQ-X, you may not see a road joining on your right as almost no light
will reach the opposite verge. Or, take a winding single-lane road. As
you lean the bike to take a right-hand bend, the right side of the beam
dips too, and you cycle into complete darkness.

I’ve often praised the way German light manufacturers make the best use
of every photon by focussing the output into useful areas. With the
IQ-X, B&M have gone too far."

from https://www.darkerside.org/2017/02/bm-iq-x-dynamo-headlight-review/