On Wed, 10 Oct 2018 16:05:06 -0700, Joerg
wrote:

On 2018-10-10 15:44, John B. Slocomb wrote:
On Wed, 10 Oct 2018 07:54:40 -0700, Joerg
wrote:

On 2018-10-09 17:01, John B. Slocomb wrote:
On Tue, 09 Oct 2018 07:57:06 -0700, Joerg
wrote:

On 2018-10-08 17:22, John B. Slocomb wrote:
On Mon, 08 Oct 2018 16:16:43 -0700, Joerg
wrote:

On 2018-10-08 16:05, John B. Slocomb wrote:

[...]

... but
having said that I might comment that it is not difficult to change
socks, even sitting on the roadside curb.


And change all the other things sitting on a curb in a business park? I
rather flick a little switch and have instant visibility. Upon arrival I
flick it again, visibility turns off. Simple.

As I said, I noticed the orange socks going up and down a kilometer
away on a bright summer day. I doubt strongly whether your super-duper
light would even be visible (in bright daylight) at that distance.


It sure is. I can say that for sure because this occasionally happens on
Green Valley Road when I have to use the car and another cyclist has
such good lighting. No orange socks. The riders with good lights are
often longhaul bike commuters. They wear nice shirts, khakis and have
panniers for their laptops and stuff.

Strange you know. I used to be a sailor and even the navigation lights
on a ship that must be visible from a 3 mile distance are hardly
noticeable in broad daylight.


Compared to a MagicShine or similar light many red and green position
lights on ships are rather dim. Also, I do not need to be seen from 3mi
away but from 1/2mi away I sometimes want to be seen.

I see. A light that can be seen from a 3 mile distance is rather dim
while a light that can be seen from 1/2 a mile is O.K.???


https://www.go2marine.com/product/16...onet-base.html

Navigation light: 30W incandescent, efficiency about 20 lumens/watt (if
you are lucky), omnidirectional 360 degrees, only vertically focused.

Mine: 8W LED, efficiency about 100 lumens/watt, not omnidirectional but
60 degree horizontal spread, similar vertical focus.

I trust you can do the math.

You certainly do not know your subject. You carefully selected a nav
light for a tiny little boat while I was talking about lights for
"ships". See
http://www.nauticexpo.com/prod/perko...71-215905.html
and then look up the light bulb (0374001CLR) which is a 30 watt bulb.

As for your claimed efficiency of the LED, so what? Can it be see from
three miles away? Certainly the U.S. Government, nor any other country
that I know of certifies shipping lights by watts, whether LED or
other . They all seem to say effectively the same thing - you gotta be
able to see it from a long way away.





--
Cheers

John B.