Originally Posted by
unterhausen
That's what I thought you meant. The Cygolite headlights have vertical cutoff using a fresnel lens, the reflector is round. It does a really good job of cutoff, and it also spreads the light wider. Back when I was paying more attention to lights, there was someone selling fresnel lenses for lights, but I'm not sure if Fenix was one of them. I see they used to have something people called the "bifocal" lens.
Run times are very short on the cygolight fronts and the battery is integrated.
I find that 0.5 amps driving a modern LED is perfect for most riding but downhill, I want to be able to drive it with about 1 amp. On an overnight brevet, I would probably need three Cygolites. With one 21700 battery in the B01, I would make it thru the night and with one cell as a spare, I would be covered in case I needed to burn the lights during the day or if I needed the higher power at night, say if it rained.
Fenix used a Fresnel lens previously. I would guess it directed 80% of the light down onto the road and maybe 20% pollution. At 250 lumens output, that would be a mere 50 lumens lost. Since many LED head lights on motor vehicles are 2-5,000 lumens and when they come over a rise, I get blinded, I am not terribly concerned with my wimpy 50 lumens in their eyes to be quite frank. I can only remember once in all my years having to deal with randonneur's spherical headlights into my eyes and that was my return on PBP. Normally, we all go in the same direction.
The Lupine SL series is probably the best beam pattern but at a huge cost in money and amps. The low setting is 600 lumens with medium 1000 lumens plus I do not think the daytime running lights can be disabled but not sure. It uses an external battery and they sell spares. This is what I would use on a velomobile and would carry spare batteries.
The Supernova minipro B54 is another really high end German spec battery light. It has a switchable high beam, 2 hours of reserve light, adjustable light sensor (say for tunnels), and a more reasonable 450 low beam. One could make it thru the night with one battery pack. Very expensive like the Lupine, maybe a little less. The zebra like online beam shots were not impressive and too risky for me to buy unless I saw one in the wild.