Flashing front light in daytime.

On 2008-05-23, wrote:
I regularly see cyclists with flashing rear lights in poor light (well
I did through the winter). They were wasting their batteries as
without exception I could see they were there before I could tell the
light was on.

Which is why I built a rear light with six 1 watt Luxeon power
illuminators (after an elderly man, not wearing glasses, who probably
drove by keeping the car between the blurred green bits which were the
edge of the road, avoiding other cars by not running into any large or
illuminated blurred bit, smashed into me doing 50 mph). Testing it on
myself, from 100ft away, I can see the flash in my peripheral vision, so
hopefully it'll also draw attention from anyone not looking at the road
while driving. I was considering a xenon strobe with a red filter, but
LEDs seemed like a better bet; no mucking around with high voltages.

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

On 2008-05-27, Dylan Smith wrote:
On 2008-05-23, wrote:
I regularly see cyclists with flashing rear lights in poor light (well
I did through the winter). They were wasting their batteries as
without exception I could see they were there before I could tell the
light was on.

Which is why I built a rear light with six 1 watt Luxeon power
illuminators (after an elderly man, not wearing glasses, who probably
drove by keeping the car between the blurred green bits which were the
edge of the road, avoiding other cars by not running into any large or
illuminated blurred bit, smashed into me doing 50 mph). Testing it on
myself, from 100ft away, I can see the flash in my peripheral vision, so
hopefully it'll also draw attention from anyone not looking at the road
while driving. I was considering a xenon strobe with a red filter, but
LEDs seemed like a better bet; no mucking around with high voltages.

I wonder what effect flash frequency has, whether to use a flicker or
something a little higher like 20Hz. If you notice that computer monitor
flicker is noticeable more in peripheral vision because peripheral
vision is designed to see changing things. This at least back when
monitors used to run at 50Hz or lower.

I find that in poor conditions, especially fog or rain, bike lights make
a huge difference.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard dot Corfield at gmail dot com
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

On Tue, 27 May 2008 17:16:50 +0100
Richard Corfield wrote:

I wonder what effect flash frequency has, whether to use a flicker or
something a little higher like 20Hz.

The flash rate is legally limited because of the distraction/
epileptic fits it might cause.

On 27/05/2008 19:51, Rob Morley wrote:
On Tue, 27 May 2008 17:16:50 +0100
Richard Corfield wrote:

I wonder what effect flash frequency has, whether to use a flicker or
something a little higher like 20Hz.

The flash rate is legally limited because of the distraction/
epileptic fits it might cause.

For an *obligatory* front light the flash rate is limited to 4Hz. See
paragraph 9(3):
http://www.opsi.gov.uk/si/si2005/20052559.htm

which becomes paragraph 12(c) of:
http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_7.htm#nsch2

For an optional front light the same requirement seems to apply (see
paragraph 10 of the 2005 SI).

--
Danny Colyer http://www.redpedals.co.uk
Reply address is valid, but that on my website is checked more often
"The plural of anecdote is not data" - Frank Kotsonis

On 2008-05-27, Danny Colyer wrote:

The flash rate is legally limited because of the distraction/
epileptic fits it might cause.

For an *obligatory* front light the flash rate is limited to 4Hz. See
paragraph 9(3):
http://www.opsi.gov.uk/si/si2005/20052559.htm

between 60 and 240 times per minute, even mark/space ratio, which would
rule out some of the pretty pattern lights on the market, though I think
that paragraph was front lights.


which becomes paragraph 12(c) of:
http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_7.htm#nsch2

For an optional front light the same requirement seems to apply (see
paragraph 10 of the 2005 SI).

Good job I posted here then, as sometimes a 20Hz or above light would be
tempting. I thought the fitting rate peaked somewhere lower than 20Hz.
Distraction, or at least being seen, is of course the aim. Maybe something
too effective, something that held attention, would cause problems.

Presumably much higher frequency switching supplies count as continuous,
which 20Hz or a little higher would almost seem to be.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard dot Corfield at gmail dot com
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

On 27/05/2008 23:43, Richard Corfield wrote:
On 2008-05-27, Danny Colyer wrote:
The flash rate is legally limited because of the distraction/
epileptic fits it might cause.
For an *obligatory* front light the flash rate is limited to 4Hz. See
paragraph 9(3):
http://www.opsi.gov.uk/si/si2005/20052559.htm

between 60 and 240 times per minute, even mark/space ratio, which would
rule out some of the pretty pattern lights on the market, though I think
that paragraph was front lights.

Sorry. I thought, from the thread header and the first post, that front
lights were the subject under discussion. I've been back and read your
post properly and see that you'd moved onto rear lights.

The same limits apply to rear lights, though, just a bit further down
the document.

--
Danny Colyer http://www.redpedals.co.uk
Reply address is valid, but that on my website is checked more often
"The plural of anecdote is not data" - Frank Kotsonis

On 23 May, 13:03, Nick wrote:
I have never thought of using a front light in daylight but was very
impressed by the result.

I'm put in mind of a recent article in .citycycling about the use of
Hi Viz and lights. The more folks wear reflectives and use ever
bigger brighter lights the more the drivers come to expect them and
stop looking out for folks without them.

On Thu, 29 May 2008 00:57:03 -0700 (PDT)
POHB wrote:

On 23 May, 13:03, Nick wrote:
I have never thought of using a front light in daylight but was very
impressed by the result.

I'm put in mind of a recent article in .citycycling about the use of
Hi Viz and lights. The more folks wear reflectives and use ever
bigger brighter lights the more the drivers come to expect them and
stop looking out for folks without them.

That's the same argument as has been made against compulsory daylight
running lights on cars - road users come to expect all 'hazards' to be
illuminated and are surprised[1] by anything that isn't.

[1] But not necessarily as surprised as the cyclist they just
stepped/drove out in front of.

POHB wrote:
On 23 May, 13:03, Nick wrote:
I have never thought of using a front light in daylight but was very
impressed by the result.

I'm put in mind of a recent article in .citycycling about the use of
Hi Viz and lights. The more folks wear reflectives and use ever
bigger brighter lights the more the drivers come to expect them and
stop looking out for folks without them.

I am in favour of Hi-Viz gear, but see the point of what you are saying.
I think it would work best if everyone uses stuff like this differently.
(The theory of Big probably says this).

e.g. with lits, some people mount a flasher on the handle bars, and
other people pretend to be Daleks with a lit on their forehead.
Doing this means other road users will not expect a standard way of
lighting cyclists, and will keep a better eye out for cyclists.

Of course we all know motorists are far more adept at see stealth
cyclists than christmas trees.

Martin wrote:

POHB wrote:
On 23 May, 13:03, Nick wrote:
I have never thought of using a front light in daylight but was very
impressed by the result.

I'm put in mind of a recent article in .citycycling about the use of
Hi Viz and lights. The more folks wear reflectives and use ever
bigger brighter lights the more the drivers come to expect them and
stop looking out for folks without them.

I am in favour of Hi-Viz gear, but see the point of what you are saying.
I think it would work best if everyone uses stuff like this differently.
(The theory of Big probably says this).

e.g. with lits, some people mount a flasher on the handle bars, and
other people pretend to be Daleks with a lit on their forehead.
Doing this means other road users will not expect a standard way of
lighting cyclists, and will keep a better eye out for cyclists.

Of course we all know motorists are far more adept at see stealth
cyclists than christmas trees.


For what is worth I got a look at it today. It looked a lot like an
Exposure Enduro Maxx Front Light.

http://tinyurl.com/6nrlh6

At £270.00 a little beyond my justification range.