Re: For those who believe in electricity

Frank Krygowski <frkrygow@sbcglobal.net> wrote:

On 4/11/2025 1:37 PM, Roger Merriman wrote:

Frank Krygowski <frkrygow@sbcglobal.net> wrote:

 
I think only a small percentage of cyclists are aware of the importance
of optics. I think almost all cyclists get their "education" (such as it
is) from product advertisements. And ever since white LEDs began their
rapid rise in lumen output, lumen counts have been the almost exclusive
message in advertisements

 
I believe most of the bike lights manufacturers have always used lenses to
greater or lesser degree, was a period when some of the Chinese led
lights/torches that where lumens only and not true figures!

I don't think that's true at all. Take a look at some of the beam shots
at this site: https://bikelightdatabase.com/beamshots
 
Or go to
https://road.cc/content/feature/roadcc-front-bike-lights-beam-test-310999
 and look at the beam shapes of the Ravemen and the Knog.

Both of which have shaped beams, Raveman and Knog both claim road specific
beams and reviews tend in Road.cc and others mention this, Raveman make lot
out of their High and low beams, though they are far from the first to do
that sort of thing!

I get why they do this, but a camera isn’t an eye and it’s rather false if
not misleading to use beam shots.

My bike lights have quite different beam shapes and output and photograph
quite differently due to that.

 
In the past few years, there's been more attention to optics, but I
think there are still plenty of small manufacturers who use rotationally
symmetrical optics. Peter White has an explanation of why those are far
from optimum, at https://www.peterwhitecycles.com/plight.php
 
 

Very small low powered mini lights and importers of very cheap frankly junk
all others seems to be shaped to some degree.

Roger Merriman