head torch power

[gaw]

Can anyone tell me how many lumens the Silva or Mila headtorches have?
I'm trying to compare them to the Hope Vision Led 2 and Led 4 which have 480 lunems and 960 lumens respectively and have been reviewed in the Fellrunner magazine (as well as the new Petzl Ultra).
Mountain bikers might be interested to know that the Hope lights now come with a bike mount, helmet mount and head harness all included as standard.

[pyrat]

Great question, I am was wondering the same the other day. Has anyone got a Petzl Ultra by the way?

[paul]

Has anyone got a Petzl Ultra by the way?

At £250 ish they are certainly not cheap but look to be rated at 350 lumens.

The Petzl Myo XP (less than £50 with BOF Cotswold discount) which is the next down from the Ultra in the Petzl LED range is quoted as 85 lumens (150 in boost mode).

[Scott]

The Petzl Myo XP (less than £50 with BOF Cotswold discount) which is the next down from the Ultra in the Petzl LED range is quoted as 85 lumens (150 in boost mode).

Boost mode cuts out after about five seconds to save overheating, so isn't much use unless you're trying to flash a distress signal. I have a Myo XP, but I find that the illumination decreases very rapidly with battery consumption on the high setting.

[Wayward-O]

Myo XP - narrow beam is too narrow and with the diffuser is just too diffuse.

[ifor]

Old style 20w Halogen like the Silva / Mila will be somthing like 200 lumen. You need to take it all with a pinch of salt as actualy mesuring the lumen output needs serious equipment. A lot of the times the quated figure is actualy just the theoretical maximum for the led's as quoted by the led munufacturers. There are all sorts of loses in a real light you will be doing well to get 70-80%

Ifor

[Wayward-O]

Maybe this translated page will help. Provides some useful info on various combinations.

20W halogen quoted at 350 lumens.

http://translate.google.co.uk/translate ... n&ie=UTF-8

[ifor]

I am not sure the numbers in the translated page realy are lumens. The milla Nova figures are well over the maximum posible for the leds in use. The line underneath says somthing about them being measured values at 3 meters. You can not measure the lumens like that. The lumens is the total output of the light in all directions you need an 'intergrating shere' to measure it. You can measure the lux which is the brightness at a given point, this would normaly be done at 1 meter not 3. Its fairly easy to get a maximum for this I have done it comparing optics for my home made lights. The numbers are about right for a lux reading so my guess is that that is what it is. The lux reading is of course very deseptive because it tells you nothing about beam angle. I have a £10 light from Tesco that will have a similar or better max lux at one meter but if you had it on your head and pointed it at you feet you could not stand in the spot so not much use for O...

Ifor

[Jagge]

I guess a good 20W O halogen is about 350 bulb lumens. One third is lost in reflectors and lenses, so it's 200+ out front as ifor wrote. As a comparison my latest DIY headlamp drives SSC P7 led at 1A, specs say it should give about 300-350 bulb lumens and it looks about as bright as my 20W halogens. So both are 200+ out front.

Petzl ultra figures are already out front and quite conseravtive. I guess it has well over 500 bulb lumens. it's a lot brighter than 20W halogen.

I hink Hope 2 led 480 figure comes from using SSC P4 leds, ratet max 240 lumens. maybe 1/10000 of those P4 leds give 240 lumens, average is something like 210. So I guess Hope is about 420 bulb lumens and about 275 out front. So it may be just a bit brighter than 20W halogen and well behind Petzl Ultra.

I also believe Mila nova is not even close 2000 lumens. Sometihing like 800-1000 may be much closer. But powerful and impressive light anyway.

I am only guessing here. I haven't seen Hope lamps, but I have seen or played with Petzl, lupine wilma & betty, 20w halogens, Mila's "1000 lumens HID" (the one I had felt like 500) and several home made ones.

[lakesorunner]

Have a look at Ay-up lights - there Aussie and incredibly bright. They are mainly designed for MTB, but now have a strap to make it into a headtorch. I used one for the night leg on a BG this summer, and the six hour battery lasted all night... Very impressive bright light, amazing burntime, and a kit of 1x6hr, 2x3hr battery, plus two sets of lights and all the clips for £270 is good value.
I think the lumens is about 680, but I'm happy to be overruled...

[Wayward-O]

Interesting lights!

My reading of the specs is that one pair of the lights (all lights are in pairs) has a combined output of 320 lumens.

[FromTheGrassyKnoll]

I think it's about time to join the LED revolution and upgrade my overdriven 20w halogen with Light Voltage Regulator and NiMH batteries to something more modern...

Please can someone advise on UK suppliers for...

Cree LEDs (Q5?)
Optics for LEDs
Heat Sink?
Constant Current Regulator

TIA
FTGK

[Adventure Racer]

overdriven 20w halogen with Light Voltage Regulator

With such a geeky setup (it's what I used before I went LED) I'm surprised it's taken you so long!

AFAIK there are still no UK suppliers of the higher spec LEDs. A quick search reveals RS and Farnell both sell Q4s though. I've bought LEDs from either http://www.led-tech.de/ or http://www.cutter.com.au/ optics and drivers from either of those, or drivers from http://www.ultraleds.co.uk/ or http://www.taskled.com/

Personally I use http://www.cutter.com.au/proddetail.php?prod=cut680 optics, which I'm more and more convinced are an almost perfect compromise between spot and flood for night-o (lucky, as they were the only optic available when I started). I use http://taskled.com/maxflex.html drivers (also available from Cutter) which are good if you want multi-modes and push button control - simpler options are available.

Currently using http://uk.rs-online.com/web/search/sear ... &R=4896079 as a heatsink.

[FromTheGrassyKnoll]

Thanks for the info.

I'm tempted just to go to cutter for most bits. Seems that it's an Aladin's cave or exciting bright glowing bits.

[FromTheGrassyKnoll]

AdventureRacer...

And funny you mention that i've been a bit slow off the mark....

I see we had a preliminary discussion in the "Silva LX" http://forum.nopesport.com/viewtopic.php?f=1&t=7265 thread on Fri Dec 01, 2006 5:32 pm!

I hope it's not another 2 years before i've built something!

Regards
FTGK