Originally Posted by
andychrist
If you commute entirely through an urban environment covered by street lamps, you'll have no need for a Magicshine, save some loot and get a blinky. But if you pass through unlighted areas, the Magicshine is the way to go. In any case you should be able to direct the beam low enough so as not to blind oncoming cyclists but still project a good field of illumination. I love my MJ816, the so called "Mickey Mouse" model (with the two little ear-like lamps attached to to the high beam) because it gives good spread on the low setting, which conserves power, and only turn it on the high for steep descents. But I just keep it on my country bikes, as it doesn't have a flash mode, which I prefer for riding in the city.
You've got it exactly backwards. When commuting in an urban environment, you should have the brightest lights you can carry. You don't need them for illumination but for letting cars know you are there. There are thousands of other light sources and a weak light gets lost in the background as this picture (stollen from mechBgon) demonstrates.
On a country road, you need the lights more for illumination and you don't have as many light sources for competition. You could run a weaker light in those situations and still get adequate illumination, although I'd run them on full in either case.
Run the Magicshine's, stbtra, and don't worry about it. The Magicshine is bright but not all that bright. They are also 'floody' so the beam isn't all that concentrated. A wide beam and our natural position on the road make for a light that is unlikely to have much effect on on-coming road traffic. If you are worried about salmons...well they are salmon. If
you are a salmon, stop doing that. And if you ride bike paths, play it by ear...or don't ride bike paths in the dark.