On 3/5/2017 5:26 PM, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 16:03:30 -0800 (PST), wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on
the hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or
four times the power.

Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No reviews
and few tests, but some interesting dynamo graphs and numbers:
http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier

This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.

Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.

WE passed 70 lumens per watt a long time
ago.http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-Directional/XLamp-MKR.
And bicycle light manufacturers are early adopters of the latest LEDs.

A dynamo can produce more than 3 watts at high speeds. In the olden days
of incandescent dynamo lights there was protection circuitry to limit
the power to the bulb by cutting off the voltage over 6V. But these high
power LEDs can handle 15W so there's no need to limit the power.

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam. The best option, to avoid annoying others,
is to not use the highest settings when riding on narrow roads or paths.
You don't want endanger yourself by using sub-par StVZO lights unless
it's mandated by law.