@Joe Chapline 9695 wrote:
This might be obvious, but I haven’t seen it mentioned. I keep the handlebar-mount adjusted so that I can change the angle of the light, and I point it down when that’s appropriate. That seems easier than covering the light with my hand. I’ve never had a problem with the mount getting looser with any of the lights I’ve used.
I do that as well. It stays reasonably well adjusted but sometimes bumps can jar it a bit, better to be pointed a bit low than high. However, unless you adjust it constantly, I still think it is better to cover with your hand because subtle elevation changes can be the difference between blinding somebody (especially when you are going slightly downhill and somebody is approaching you coming uphill) or not. Think about it when you are driving a car as well, a car approaching you from a higher elevation will appear to have its high beams even though it does not. The same principle can occur on a bike.