LED verses incandescent bulbs front lamp

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petzl
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LED verses incandescent bulbs front lamp

Postby petzl » 1 Dec 2012, 2:09pm

After looking at previous posts and becoming bogged down I am left with several questions on the same subject. I will probably have to post again but first off;
For a front lamp is an incandescent bulb such as an halogen bulb as good as LED?

I have been using a Bush and Muller Lumotec dynamo front lamp with a halogen bulb and by choosing a suitable voltage bulb I have powered the lamp with NiCd/NiMH and LiPo batteries. All leave room for improvement and I suspect the lamp/lens is the problem.

I have got a caving (miners) cap lamp powered by NiCd and another set up with lead acid. 6 to 9 hours run time on full beam is normal. Although they have an impressive penetrating beam there is no spread of light close up and in any mist the light scatter is very troublesome. However, the lamp/battery assembly is bombproof as would be expected with something that is bounced off rocks underground. Before anyone says it, I do not need reminding how heavy such units are.

Update.
Oh dear I think the bog is becoming deeper.
I have just finished reading Peter White Cycles article on lamps and after reading the threads to my posting I am led to believe that a lamp lens for an LED is not the same configuration as for an incandescent bulb. Furthermore, an LED lamp will produce superior illumination and brilliance in front of the front wheel in street lighting conditions wheras an incandescent bulb lamp will throw a beam forward and up the road in dark (un-lit) road conditions.
Perhaps in an ideal world, two lamps would be the solution.
Last edited by petzl on 1 Dec 2012, 4:04pm, edited 1 time in total.

robc02
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Re: LED verses incandescent bulbs front lamp

Postby robc02 » 1 Dec 2012, 2:21pm

For a given amount of electrical power (Watts) a modern LED will emit considerably more light (Lumens) than a halogen lamp - this is why comparisons using Watts are now practically meaningless.

Most LEDs emit a slightly bluish light (though this is changing) compared to the slightly yellow light of a halogen lamp. Some users report that they find the latter preferable in wet conditions.

As you suggest, total light output (whatever its colour) is not the only consideration. Where the light shines is also of major importance, hence the sophisticated and expensive optics used to control the beam pattern in many premium lights - notably dynamo powered ones.

Brucey
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Re: LED verses incandescent bulbs front lamp

Postby Brucey » 1 Dec 2012, 2:51pm

petzl wrote: For a front lamp is an incandescent bulb such as an halogen bulb as good as LED? .


the simple answer to this is 'no'. As indicated above the amount of light you get is simply a lot greater with good LEDs.

By way of example, take a look at domestic light bulbs; halogen bulbs with a 25-30W rating are now routinely changed for LED bulbs with a 2-3W rating. If it sounds like you get up to ten times more light with the LED per Watt, it is because this is pretty much how it is.

Cool white LEDs make most light, but 'warm white' ones have a better spectrum (and therefore better colour rendition) at a cost of loss (in lumens) of typically 5-10%. Good commercially available LED devices at present make about 50-70 lumens per watt. Models with about 100 lumens per watt have been demonstrated, but are not yet widely available.

You can get LED bulbs that replace incandescent ones in torches etc. Reflectalite sell them

http://www.reflectalite.com/

to fit into existing housings where (depending on what you get) you can have more light and/or a longer run time.

However the LED will emit light slightly differently, so the beam pattern, although similar, will not be quite the same. Furthermore, if the optical design/beam pattern was fundamentally poor to start with, an LED bulb won't fix it. I have found when installing LED bulbs in (say) Maglites, the beam is often improved, but this is an unusual outcome.

The latest B&M designs not only make a good number of lumens per watt, they also have super beam patterns (different with different models). They are not cheap though.

hth

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

thirdcrank
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Re: LED verses incandescent bulbs front lamp

Postby thirdcrank » 1 Dec 2012, 3:12pm

Modern bike lighting is immeasuarbly better than it was 10 - 15 years ago. I remember something from CJ published possibly in 1995 when he prophesied that the future was in LED's and how right he was.

As has been implied, there are a couple of different things involved here. The light source and LED's win hands down, IMO, then the lamp design ie reflector and "lens." The good designs direct the light where it's most effective, and avoid shining it where it's not wanted. I see no purpose in dazzling other people.

My regular night riding days (a contradiction in terms ?) are over so I'm not up-to-date with current models but those are the things to bear in mind, IMO.

One more advantage of LED's over bulbs which I don't think has been mentioned is reliability. Now that the man who was in charge of battery connections at the Ever Ready factory has been banished, reliable bike lamps are a reality. :D

robc02
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Re: LED verses incandescent bulbs front lamp

Postby robc02 » 1 Dec 2012, 3:20pm

There's a load of information on the Transportation Lighting / Bicycle section of Candlepower Forums. There is some good DIY work going on but, as far as I can see, it uses flood lighting methods rather than the carefully shaped beams of the best commercial lights.

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gentlegreen
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Re: LED verses incandescent bulbs front lamp

Postby gentlegreen » 1 Dec 2012, 3:29pm

robc02 wrote:There's a load of information on the Transportation Lighting / Bicycle section of Candlepower Forums. There is some good DIY work going on but, as far as I can see, it uses flood lighting methods rather than the carefully shaped beams of the best commercial lights.

Sadly 99 percent of lights in use are unsuitable for road and path use un-modified.

One of these days I'm going to get to see the inside of a Philips and make myself a mirror.
In the mean time I use an oversize battery (12 volts 3.7AH), a £10 domestic triple LED spot - around 6 watts, plus a yoghurt pot and an aero wrapper to correct the beam.

I often get nostalgic for old-school incandescents - though I sometimes get the odd idiot managing to kill my night vision with one.

howfar
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Re: LED verses incandescent bulbs front lamp

Postby howfar » 1 Dec 2012, 5:42pm

I've got a B&M Lumotec on my Brompton and replaced the bulb with a dynamo compatible LED - the beam is much whiter and the light spead close to the bike is brighter - the beam spread ahead of the bike is nowhere near as good as the halogen bulb. Just goes to show a lamp designed for halogen even with a brighter LED doesn't always give better performance. The old halogen bulb is now back in.

The same LED bulb in a 6 cell maglite gives excellent output for much longer battery life.

Having found my old Ever Ready 2 D-cell front and back lights I put a white and red LED in - much brighter and seem to last forever even with 1.2V rechargable D-cells. The front beam spread is great even with naff bricklike retro styling!

SA_SA_SA
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Re: LED verses incandescent bulbs front lamp

Postby SA_SA_SA » 2 Dec 2012, 2:18pm

Having found my old Ever Ready 2 D-cell front and back lights I put a white .... LED in - much brighter and ...... The front beam spread is great even with naff bricklike retro styling!


This would suggest that for replacement white LED 'bulbs' (like those of reflectalite.com), the best host lamp is one with a narrow beam such as old battery lamps or maybe SA dynohub lamps. The large emitter size of the LED will then make the less focused beam wider, like a dynamo.
------------You may not use this post in Cycle or other magazine ------ 8)

willem jongman
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Re: LED verses incandescent bulbs front lamp

Postby willem jongman » 2 Dec 2012, 4:15pm

If you want a better headlight there is only one good way: buy a good modern led light. For urban riding the B&M Lyt or Philips Saferide 40 are very good. If you need more light on the road and further into the distance, the light to beat is the B&M Cyo (avoid the R version) or the brighter and better made upmarket version of this light, the Edelux from Schmidt. If you want a wider beam for riding on gravel roads etc, the Philips Saferide 60 is the best, unless you are prepared to fork out more money for the new B&M Luxos. But be prepared for the high prices of all these lights (German on line retailers have them cheaper, however).
Willem

thirdcrank
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Re: LED verses incandescent bulbs front lamp

Postby thirdcrank » 2 Dec 2012, 5:24pm

howfar wrote: ....Having found my old Ever Ready 2 D-cell front and back lights I put a white and red LED in - much brighter and seem to last forever even with 1.2V rechargable D-cells. The front beam spread is great even with naff bricklike retro styling!


The Ever Ready lamps which clip in and out of the deep suare "U"-shaped bracket (Night Riders) really did have a good front beam pattern and IME they were the best of the lamps specifically designed to meet the then new British Standard. If you can buy a replacement LED "bulb" which fits in the lamp so the light source is in exactly the right position they should be a good lamp. (See Brucey's comment on this issue above.)

"Older readers" will probably remember that when LED's began to be suitable for bikes, the red ones were originally much better than anything white(ish.) I used some replacements in a rear lamp and the effect was to concentrate all the light in a smallish area in the centre of the red lens. The current drain was so low it didn't do the nicad rechargeables much good in that they were never discharged. Again IME, the internal connections in those lamps were typical Ever Ready.

Ayesha
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Re: LED verses incandescent bulbs front lamp

Postby Ayesha » 2 Dec 2012, 5:27pm

http://www.ehow.com/facts_5953769_halog ... ption.html

100 Watt Halogen bulb produces 1800 lumen :shock:
20 W LED produces 1800 lumens.

BigG
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Re: LED verses incandescent bulbs front lamp

Postby BigG » 2 Dec 2012, 8:52pm

LEDs win hands down on grounds of reliability and long life, but the additional brightness would not be necessary were it not for the other road users. Many years ago, a 2.4 watt tungsten (not even halogen) front light was more than adequate for rding at speeds of about 25mph on unlit roads because our eyes adjusted to the light level. Even oncoming car headlights were not very bright and did not affect the eyes' adjustment too much. Today, car headlights have become very bright and our eyes - and the motorists eyes - react to this higher light level. It is in my view now necessary to use modern LED lights both to see and be seen. The world in which we ride has changed and we must change with it.

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gaz
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Re: LED verses incandescent bulbs front lamp

Postby gaz » 17 Dec 2012, 11:58pm

Brucey wrote:You can get LED bulbs that replace incandescent ones in torches etc. Reflectalite sell them

http://www.reflectalite.com/

Thanks for the heads up.

I've just ordered one through their ebay shop: http://myworld.ebay.co.uk/bikeco_uk?_tr ... 7675.l2559 .

This is in an effort to drag my Cateye Daylites into the 21st Century. I'll report back, hopefully with pictures.

Edits - Link to review, pics included.
Last edited by gaz on 7 Mar 2013, 6:24pm, edited 2 times in total.
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Mick F
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Re: LED verses incandescent bulbs front lamp

Postby Mick F » 18 Dec 2012, 7:54am

BigG wrote:LEDs win hands down on grounds of reliability and long life, but the additional brightness would not be necessary were it not for the other road users. Many years ago, a 2.4 watt tungsten (not even halogen) front light was more than adequate for rding at speeds of about 25mph on unlit roads because our eyes adjusted to the light level. Even oncoming car headlights were not very bright and did not affect the eyes' adjustment too much. Today, car headlights have become very bright and our eyes - and the motorists eyes - react to this higher light level. It is in my view now necessary to use modern LED lights both to see and be seen. The world in which we ride has changed and we must change with it.
+1
Well said.

It's an arms race.
Mick F. Cornwall

jb
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Re: LED verses incandescent bulbs front lamp

Postby jb » 18 Dec 2012, 8:51am

Reasons for using Halogen lamps in 2012

1) Your Granny left you a tea chest full of bulbs in her will.
2) You like bumping into things
3) You like running a 1 bar electric fire on the front of your bike to keep the world warm.
4) Your an old pipe smoking grump who will defend any old out-dated naff technology to the death.
5) you have a vintage collection of bikes that will never be used in the dark.
6) A tiny tinge of sadistic pleasure always envelopes you as your mates freeze to death watching
you fiddle with the bulb contacts in the rain.
7) Parting with money whilst there is the tiniest spark of life in the old selotaped together crud encrusted shell is non negotiable.

They were good once, but time moves on.
Cheers
J Bro