This one has it all....

Polaris,
the information i gave is from www.friluft.se which is also the company that i have ordered my L1 from.

The L1 does not have any headstrap,but Silva claims that it will be stable enough without it for running. Regarding the heat-sink i have no idéa how good it is.

Our local outdoor shop asked Hombel about the availability of the L1.
According to Hombel the L1 should be in stock "somewhere" in May.

Icarus - interesting to note that things are also delayed in Belgium. I think it is likely that the L1 will first be available in Sweden. It will be surprising if it turns up at Trig Instruments (New Zealand), as quoted earlier in this thread, before it is available in Europe.

NorthernStar - thanks for your advice. I was also in touch with friluft last week. It is interesting to hear that Silva believe that the L1 is stable for running, even though it does not have a top-strap.

On the heat-sink, I would be surprised if there were a problem. The official PDF manual says that the temperature operating range goes from - 40 deg C up to 60 deg C. It seems unlikely that Silva would make an error on a basic point like that. If it can cope with 60 deg C, then that suggests that there would be a significant margin when used at normal (north European) temperatures. (The only thing that makes me sceptical is the fact that exactly the same temperature operating range is quoted for the L2, which has a 1 watt LED instead of 3 watts LED, but which otherwise seems to have a similar construction).

Silva also make orienteering headlamps with 20 watt halogen bulbs, so they should have a lot of experience of heat dispersal.

Bad news! /ubbthreads/images/graemlins/frown.gif

Today i got mail from Friluft.se and they told me that the Silva L1 got delayed further /ubbthreads/images/graemlins/icon23.gif. Now estimated time of delivery is May 3-4. POOR of Silva!

Now we have to wait another week. That´s the situation now....

I guess we will have to be patient. Let us hope that the delay means that Silva L1 will not suffer from the kinds of problems that are liable to arise if things are rushed.

NorthernStar - depending on how far north you are in Sweden, the new headlamp may remain unused for some time because of the extended summer daylight. If, as expected, I get back to the north of Norway this July, I will not take a headlamp!

Polaris,
I don´t live so far up north so that i can take benefit of the midnight sun.When being far north up in Sweden there are no need for a head lamp during the summer. The midnight sun gives all the light one needs.

I live around the Stockholm area,and even though there are no midnight sun here,it is very bright nights during the summer. One does not get so mouch use of the headlamp during the summer where i live either. It´s mostly when it´s cloudy skies that it gets realy dark during the summer,and then one have the use of headlamps and flashlights.

Still in April,there are dark nights and i need a headlamp while jogging. I am really eager to test the Silva L1 /ubbthreads/images/graemlins/smile.gif.

NorthernStar - You are at about 59 deg N, and I am at 53¾ deg N, so the summer nights here are longer and darker.

It will be interesting to see what kind of running is possible with a 3 watt luxeon star. I do a bit of "fell running" in places that are steep and rough. Going downhill one goes really fast, and it is easy to twist an ankle. My 1 watt luxeon star headlamp (PT EOS) is not powerful enough for that kind of running - although it was just about adequate when there was snow on the ground. How will a 3 watt light cope? I am not expecting miracles - there is a good reason why Silva make headlamps with 10 - 20 watt halogen bulbs.

It will not be as powerfull as Silvas headlamps with 10 - 20 watt offcoarse. However,the L1 is a really powerfull lamp that can give a throw to up to 100 meters when in the Ultra bright mode. That is probably an overstatement,but lets say it can probably give a good throw up to 90 meters. The manufacturers usualy gives overstatements regarding the throws on headlamps and flashlights.I belive the L1 will be a good headlamp for running.

Hello all.

Yesterday I finished a review/test of headlamps for adventureracing. Except for big headlamps like Silva 478 and Mila PLS 100, we tested a lot of diffrent smaller LED lamps like Silva L1, Petzl MYO XP, Princetontech Corona and soo on.. We gave them a realy hard time. /ubbthreads/images/graemlins/smile.gif

The test will be published in the swedish crosscountryskiing magazine GLID, in the May edition.

The testpatrol was all members from the adventureracing team adventureteam.se. Visit our homepage on www.adventureteam.se

Regards Fredrik.

Most tantalising, Fredrik. Are you please in a position to give an outline of what you thought of the Silva L1? I imagine that very few of the readers here can read Swedish, and few of them will have access to the Swedish Cross Country Magazine.

Agreed... if I could read Swedish, and had access to the magazine, I'd buy a copy, but since neither applies, I'm out of luck! I'd love reading about all of them, though... is a version of the article likely to appear on the web?

The multisport magazine "Glid Multisport" that has the article about the L1 that Fredrik mentions,is not in print until May. The PDF link is just an advertisement for the coming magazine.It looks like the magazine will only be printed in Swedish,but i am sure that the folks at Glid Multisport could arrange a translated version on the L1 article on the Internet for those who are interested.

A note on batteries for the Silva L1.

Silva say that the L1 has a 3 watt Luxeon LED, and the regulated "ultra bright" output should last 2¼ hours with 4 AA alkaline batteries. If you assume that average voltage for an AA battery is 1.3 volts over the discharge cycle, then a current of 575 mA would be required to generate 3 watts from 4 batteries. It seems that is beyond the comfortable load of an AA alkaline battery. Indeed, if you assume capacity of 2,500 mAh and average voltage of 1.3 volts, 4 batteries should generate 13 watt-hours. The L1 would only require 6¾ watt-hours for 3 watts of output for the claimed 2¼ hours.

If a current of 575 mA is required for "ultra bright", then it appears that NiMH batteries may work better at that output level.

You don't get 13 Wh from 4 AA alkies, from Silverfox's Alkaline shoot out you will see that on average you will get around 1.7 Wh from one AA battery if dischareged at 0.5A. That translates into 6.8 Wh for 4 batteries, something that correlates well with their clamed runtime if the rest of your numbers are correct.

Sigbjoern

I do not think there is any disagreement here. I was trying to indicate that 575 mA was beyond the comfortable output of an AA alkaline battery. The 2500 mAh capacity that I mentioned is the kind of nominal figure often quoted for such batteries. If the <font color="blue">available</font> energy at 500 / 575 mA discharge is roughly one half of what the battery is storing, it simply demonstrates that alkaline batteries are inefficient where high discharge currents are required. Hence my conclusion that it was likely that NiMH batteries would perform better than alkaline batteries when the Silva L1 was used at "ultra bright".

The actual performance with NiMH batteries would depend not just on the nominal battery capacity, but also on the trigger that the Silva L1 regulation circuit uses to switch out of "ultra bright" mode.


PS - I know what the Norwegian word <font color="blue">Lurveleven</font> means. I claim my 100 NOK.

Polaris, yes you are right about thinking NiMHs will perform better, in most cases they will do. But in this case I think the performance will be quite similar, so it will depend on the quality of the Alkalines and the capacity of the NiMHs used what gives you most runtime. At least that is the conclusion I can draw from Silverfox's test data. When I get this light I will of course do a test on this.

Btw, in a regulated light I don't think 0.5A is pushing the AA too hard, but I wouldn't use them on anything more demanding.

PS - I will not make a <font color="blue">hullabaloo</font> of you finding out what my nick means /ubbthreads/images/graemlins/wink.gif I think the English meaning of the word is quite cool as well. I get the impression you have been to Norway quite a bit so if you stop by my house next time you visit you can pick up your 100 NOK bill, or maybe you instead can help me get rid of that £20 bill left over from my last UK trip.

Sigbjoern

Lurveleven - I will await with interest your practical measurements, with different battery types.

I have used NiMH batteries in a few regulated lights, and have generally found that they seem to work well. But the only detailed measurements I have concern use in low discharge devices. One advantage of such batteries is their tolerance of low temperatures. Gold Peak, as an example, officially say that their NiMH batteries are designed for discharge down to -20 deg C. Unofficially they have even mentioned - 30 deg C. I was using a PT EOS (3 x AAA NiMH) in March at temperatures down to - 20 deg C, and it worked fine.

[20 GBP for 100 NOK sounds like a good exchange rate. But I usually go "up north" to avoid the Bergen rain.]

I work about 5 minutes drive from Trig Instruments and should be getting mine on Wednesday (the 4th) so I'll let you know what I think.

I wonder how it compares against the new Petzl Myo XP...

First impressions on Silva L1 that arrived 3 hours ago.

<font color="blue">Physical features</font>

My initial impression is the light is well-built, using good materials. It appears robust.

As shown on Silva's illustrations, the light has 2 rear battery holders (2 AA batteries each). But one aspect of the design has changed from what is currently illustrated on the web-site. The illustration shows a plug connection at the left hand (rear) battery case. This has been replaced by a good quality but slightly bulky cable connector a few cms from the lamp housing. Between this connector and the battery housing there is now a short helical cable section. [The need for the connector arises from the provision of an alternative battery housing for use of 4 C cells].

On my measurements, the light is slightly overweight (241 g with 4 AA alkaline batteries - Panasonic brand supplied - as compared with claimed 226 g). For the sake of completeness, weight with 4 AA NiMH batteries (GP 2100 mAh) is 259 g. Basic weight of the unit without batteries is 148 g.

A good quality mesh bag. (weight 23 g) is supplied.

The separate plastic battery holder (for 4 C batteries) comes with a substantial helical cable section, and has what appears to be a good quality belt holder (plastic) (Weight excluding batteries is 119 g)

As claimed, the rear battery holders can be detached from the head-band. The front-plate, which supports housings for the light, circuitry and switch, cannot be detached from the head-band.

The head-band, as indicated by Silva, is without top-strap. The band has 2 wavy lines of some non-slip substance to improve grip. The head-band does seem to grip well, and the light seems surprisingly stable in the absence of a top-strap. The fact that the non-slip strips are very narrow should mean that absorption of perspiration will be unaffected. What I do not like about the head-band is its limited adjustment range, which may arise as a result of the use of two battery holders in order to distribute weight. It seems to me that, with the strap adjusted for greatest length, the strap is rather tight (for my admittedly large cranium). (Perhaps the band will stretch with age).

As the front plate has a substantial aperture, it appears that it would be possible to rig a top-strap, if someone wanted to do that.

As shown on Silva's illustrations, the light housing is supported by a hinge on the left side. This is unorthodox, but it provides excellent support for the very light lamp unit. Stability is not in question.

The switch (mounted on top of a housing extending from the left side of the front plate) is more or less flush with the top of the surface on which it is mounted. It is rather stiff and is without auditory or tactile feedback. It might not be easy to operate the switch with heavy gloves, or with very cold fingers.

In order to switch the light on or off, the switch needs to be depressed for about 2 seconds. Given the stiffness of the switch, and this 2 second interval, it is most unlikely that the light could come on accidentally in a rucksack.


<font color="blue">Electrical features</font>

When the light is first switched on, it comes on at low setting. Brief depressions of the switch allow the light to cycle on to medium, high ("ultra bright"), and flashing modes. A further depression takes one back to the start of the cycle. What I like about this is that the device starts at the lowest setting, thus minimising potential loss of night vision. This is unusual and desirable.

The circuitry appears to be in the small plastic housing under the switch.

As it is currently broad daylight, a proper assessment of the beam is not possible. In a dark garage, the beam appears to be fairly tightly focussed with limited side-spill. The 3 illumination steps are well separated. Even at medium setting the L1 evidently produces more light than PT EOS (1 watt device, I believe) on high. The colour of the light appears to be pure white, to my eyes at least.

When the light is at low and medium, it produces a slight buzzing noise. Technically competent people may be able to infer salient aspects of the circuitry.

There is a 2.5 cm wide metal plate at the rear of the lamp housing, which has fins whose edges are covered by plastic arches. This arrangement is obviously for heat dispersal. I cannot make a technical judgement about the heat-sink, but the signs are encouraging.

I have not run any battery-life tests. I merely make the comment at this stage that the light seems to work well on NiMH batteries.


<font color="blue">Initial conclusion</font>

There are many good things about this light. It produces a lot of light, the light levels appear to be well stepped, the unorthodox support of the light housing is very secure, and it seems generally well made. My main question concerns the shortness of the head-band, and its adjustment range.