Author Topic: Light testing - the results  (Read 60572 times)

Lycra Man

  • SR 2011, 2012 & RRTY
Re: Light testing - the results
« Reply #50 on: December 01, 2008, 01:56:55 pm »
Well done everybody. Excellent test providing unbiased results.

FWIW I have just purchased a Shimano dynohub and B&M Lumotec IQ Fly, to replace my Smart BL201H rechargeable.

I rode out for a short test on Saturday night, and am VERY pleased with the result, although my gear cables are in the way, so will have to tie them back somehow.

Incidentally, for those interested in weight savings, the Smart light plus battery plus wheel/tyre weighed EXACTLY the same as the Shimano DH-2R40 Dynohub, wheel, tyre and IQ Fly = 2.655kilo.

For thsoe intested in cost, the Smart I picked up for £26.00. The dynohub I bought privately off eBay for £46, and the B&M Lumotec IQ Fly was £65.00, so a dyno combo for £111.00. I had always promised myself a SON hub and Solidlights, after reading the input of many others, but still cannot afford it.

Lycra Man

Jules

  • Has dropped his aitch!
Re: Light testing - the results
« Reply #51 on: December 01, 2008, 02:21:00 pm »
Fantastic piece of work.  Thanks  to you all ;D

IQ Cyo for me I  think.

Is that a bakfiets in your profile pic? My Cyo is on my bakfiets, and it's a 60 lux. If you were worried that you'd miss the 40 lux nearfield thing, don't. With the combo of the low mounting position and the box, I don't get any sense of things disappearing from view as my front wheel approaches.

HTH

It's something Dutch and huge but not mine alas.
Audax on the other hand is almost invisible and thought to be the pastime of Hobbits ....  Fab Foodie

donpedro

  • ain`t haulin` any lambs to the marketplace anymore
    • But, I'm Swedish!
Re: Light testing - the results
« Reply #52 on: December 01, 2008, 02:27:42 pm »
Thanks for a stellar job!
So should I take the plunge and return my first ed Dinotte 200 AA for a upgrade now or wait a while longer?   :-\
"A society is defined not only by what it creates, but by what it refuses to destroy."

Charlotte

  • Dissolute libertine
  • Coffee snob and pencil fetishist
    • charlottebarnes.co.uk
Re: Light testing - the results
« Reply #53 on: December 01, 2008, 02:35:23 pm »
Alas, the management cannot take that decision for you...
Commercial, Editorial and PR Photographer - www.charlottebarnes.co.uk

Re: Light testing - the results
« Reply #54 on: December 01, 2008, 02:43:20 pm »
Just a thought that may help decide potential buyers, in the UK.
The only lights on test that are BS, or equivalent, approved are the IQ Fly and Cyo lights. (possibly Edelux and Inoled too)

donpedro

  • ain`t haulin` any lambs to the marketplace anymore
    • But, I'm Swedish!
Re: Light testing - the results
« Reply #55 on: December 01, 2008, 02:57:53 pm »
Alas, the management cannot take that decision for you...

Oh you all knowing velovixen - just give me the sign!  ;D
Would have been interesting with some rough bang-for-buck comparison too. Btw, was that a upgraded/latest ed Dinotte 200 Li-Ion you used?
"A society is defined not only by what it creates, but by what it refuses to destroy."

Pingu

  • Put away those fiery biscuits!
  • Mrs Pingu's domestique
    • the Igloo
Re: Light testing - the results
« Reply #56 on: December 01, 2008, 03:03:46 pm »
What that in itself also means is that we have a variation on Moore's Law:

The output of bicycle lighting systems will double in power every two years.

We're all going to fry  :D

Zipperhead

  • The cyclist formerly known as Big Helga
Re: Light testing - the results
« Reply #57 on: December 01, 2008, 03:08:29 pm »
Would have been interesting with some rough bang-for-buck comparison too.

I didn't have prices for all the lights tested, so I couldn't do that. If I can finish collecting prices, then it should be easy enough (obviously have to factor in dynohub cost as well)
Our son does know who Boz Scaggs is, we've done ok as parents.

Re: Light testing - the results
« Reply #58 on: December 01, 2008, 03:37:00 pm »
Just a thought that may help decide potential buyers, in the UK.
The only lights on test that are BS, or equivalent, approved are the IQ Fly and Cyo lights. (possibly Edelux and Inoled too)

The Inoled is. I'm sure any of the German lights, assuming they're sold in Germany, will be.

Zipperhead

  • The cyclist formerly known as Big Helga
Re: Light testing - the results
« Reply #59 on: December 01, 2008, 03:38:15 pm »
OK.. I can probably borrow a digital projector for that to save on paper.

I think that it would probably lead to slightly skewed results - at the very least you would get a bike shaped shadow on the target!
Our son does know who Boz Scaggs is, we've done ok as parents.

Re: Light testing - the results
« Reply #60 on: December 01, 2008, 03:50:52 pm »
What setting did you use for the Fenix P2D? Normal or turbo.

If Normal, then I'd guess that the E20 (same output as the P2D) is going to win the bang-for-buck competition.
<i>Marmite slave</i>

Charlotte

  • Dissolute libertine
  • Coffee snob and pencil fetishist
    • charlottebarnes.co.uk
Re: Light testing - the results
« Reply #61 on: December 01, 2008, 03:54:38 pm »
What setting did you use for the Fenix P2D? Normal or turbo.

If Normal, then I'd guess that the E20 (same output as the P2D) is going to win the bang-for-buck competition.

Turbo.  All battery lights were ramped up to max.
Commercial, Editorial and PR Photographer - www.charlottebarnes.co.uk

Julian

  • samoture
Re: Light testing - the results
« Reply #62 on: December 01, 2008, 03:55:50 pm »
What that in itself also means is that we have a variation on Moore's Law:

The output of bicycle lighting systems will double in power every two years.

We're all going to fry  :D

Cyclists as eco-terrorists?  Not if we're going to be responsible for climate change by bicycle light!  ;D

Re: Light testing - the results
« Reply #63 on: December 01, 2008, 03:57:28 pm »
What setting did you use for the Fenix P2D? Normal or turbo.

If Normal, then I'd guess that the E20 (same output as the P2D) is going to win the bang-for-buck competition.

I think, all things considered, it wins anyway in that respect.

Re: Light testing - the results
« Reply #64 on: December 01, 2008, 05:43:27 pm »
Just a thought that may help decide potential buyers, in the UK.
The only lights on test that are BS, or equivalent, approved are the IQ Fly and Cyo lights. (possibly Edelux and Inoled too)

The Inoled is. I'm sure any of the German lights, assuming they're sold in Germany, will be.
The Supernova E3 isn't.  There's a different model with an asymmetric lens that is presumably meant to be. There were beam shots in an extract from an german bike map that someone posted a while back.
The Edelux is "approval pending" or some such.

Edit:
Beam shots on the Schmidt site here

Re: Light testing - the results
« Reply #65 on: December 01, 2008, 06:13:32 pm »
I don't suppose there's a way of measuring the electrical power drawn by the dynamo lights?  I bet they're not all 3W.
Never tell me the odds.

simonp

  • Omnomnomnipotent.
Re: Light testing - the results
« Reply #66 on: December 01, 2008, 06:34:07 pm »
I don't suppose there's a way of measuring the electrical power drawn by the dynamo lights?  I bet they're not all 3W.

I think if they end up with a square wave out of the SON then they can draw more than 3W without destroying the rear light in the process.


simonp

  • Omnomnomnipotent.
Re: Light testing - the results
« Reply #67 on: December 01, 2008, 06:43:55 pm »
One thing I noticed was the difference between the IQ Cyo and the Edelux.  Looking at the pics on manual, it seems that the Edelux wasn't aimed at the centre of the target.  This might explain why the centre and 1M readings are in the same ballpark as each other for the Edelux whilst the IQ Fly and Cyo both have a huge difference.

Re: Light testing - the results
« Reply #68 on: December 01, 2008, 07:24:30 pm »
What that in itself also means is that we have a variation on Moore's Law:

The output of bicycle lighting systems will double in power every two years.

We're all going to fry  :D

Cyclists as eco-terrorists?  Not if we're going to be responsible for climate change by bicycle light!  ;D

I always considered hub dynamos to pretty green.
Looks like the IQ Cyo or Fly for me then. The Cyo seems to have the edge.
Interesting that the Lupine is still the king. It's been the top choice for off roaders for some time.
It would have been interesting to see more off road Li-Ion set ups. There are so many now though.

Re: Light testing - the results
« Reply #69 on: December 01, 2008, 07:41:46 pm »
One thing I noticed was the difference between the IQ Cyo and the Edelux.  Looking at the pics on manual, it seems that the Edelux wasn't aimed at the centre of the target.  This might explain why the centre and 1M readings are in the same ballpark as each other for the Edelux whilst the IQ Fly and Cyo both have a huge difference.

With Charlotte pedalling at 15mph, two or three people holding onto her and the bike, and someone else adjusting/pointing the lights, there was only limited time to adjust the lights for optimal beam pattern projection.

At the end of the day, whilst it was attempted to make this as scientific as possible, we only have two measures from the beam pattern, which is a fairly crude metric.  If we really wanted a good measurement, we would need a proper rig for making a complete beam pattern measurement in both the horizontal and vertical axis, but I think if we were going to those lengths, we would also replace the dynamo by a simulated source, all of which would be a lot more complex, expensive, and take a fair amount of development.
Actually, it is rocket science.
 

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: Light testing - the results
« Reply #70 on: December 01, 2008, 08:03:58 pm »
The other pinch of salt to add to the mix is the batch variation between LEDs. Take any two lights of the same brand and they will have slightly different light outputs. On my dual head AyUps I can see a distinct difference in brightness between the two heads.

So really we need to repeat this enough times to get a reasonable distribution average for each light..

Any takers?







* listens *








* hears pin drop *







'K, we'll just go with that then...

..d
"By creating we think. By living we learn" - Patrick Geddes

simonp

  • Omnomnomnipotent.
Re: Light testing - the results
« Reply #71 on: December 01, 2008, 08:11:07 pm »
What it would need to get better, consistent results, is a test rig as TimC says.  For best realism I reckon a SON-equipped front wheel, a DC motor, some turbo trainer spare parts, an old pair of front forks, appropriate mounting hardware, and some control gadgetry to regulate the speed (servo controller maintaining a constant speed rather than position).

Could be done for under £100 if you already have the wheel and the spare forks I reckon.

If the setup was clever enough you could even have some indication of power usage - if you can measure the current required to maintain the constant speed then you should be able to work out the wattage.

Re: Light testing - the results
« Reply #72 on: December 01, 2008, 08:13:17 pm »
Wouldn't it be easier to get an AC source and an appropriate transformer?  Maybe Kathy could borrow one from the lab?
Never tell me the odds.

nicknack

  • Fledgling Swampy
Re: Light testing - the results
« Reply #73 on: December 01, 2008, 08:15:28 pm »
Did those that took part in the testing have a subjective opinion about the ranking of the lights that differed from the measured rankings?
This old man came rolling home.

Re: Light testing - the results
« Reply #74 on: December 01, 2008, 08:18:08 pm »
That makes sense. Resistors have variation in their level of resistance, within a tolerence. So every electrical circuit with the same wiring and same grading of resistors will have a slightly different rersult.
Same for the diode. The electrical property of the raw material used for LEDs alters within the same "crystal*"
and each one of those is slightly different. There are also differences in structure too as well as other factors. So a semiconduter wafer could be different from another from the same ingot.



*Which could be made of several types of material. I used to cut them into semiconductor wafers between 2001 and 2005. They would then be used to make diodes and numerous other things by our customers. I don't know which was used for LED lights though, I just used to cut them.