On Monday, December 4, 2017 at 10:47:49 PM UTC-5, Tim McNamara wrote:
On Mon, 4 Dec 2017 08:33:32 -0800, sms
wrote:
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/

Interesting review, thank you for that. Not sure that the photo mimics
how the human eye sees at night (always a problem with this sort of
thing).

Well, in any event there are wider beams if you wish. Scroll down to
the eDelux II/B&M Premium CYO/etc.:

http://www.peterwhitecycles.com/headlights.php

Scroll further down to the Schmidt eDelux, which is what I have on my
bike now (eDelux II on the way as we speak for my other bike). I find
the eDelux quite adequate for in town and rural night riding. Heck, I
have ridden dusk to dawn with B&M halogen lights and been quite happy
with them- used them for 300k, 400k, 600k and 1200k brevets on roads (my
eyes are now 15 years older and don't see quite as well by those lights
as they used to).

Not bright enough and you don't see well enough; too bright and you
don't see well either because near objects are too bright and interfere
with dark adaptation. Too narrow causes the same sort of problem. The
top of the beam should be brighter than the bottom. Some scatter to the
sides is helpful, scatter above the horizon is not (I notice even my new
Subaru has a sharp upper cutoff to the headlight beams). It's easy to
get into thinking that brighter is always better, in which case one will
ultimately ride only during the day in full sun.

And even then there are those who believethat you MUST use super-bright flashing lights in the daytime.

What I like to see on a website is an image of the ACTUAL BEAM PATTERN on the road not a wall.

Cheers