XP myo

[darkplaces]

And I thought 5W was bright! 10W! - blinding. You must find GB Cavern impressive (cos you're probably the only person who can see the whole chamber).

Yes GB was impressive with a bright light I really do like LEDs due to the even, unbanded light. It seams easier on the eyes too. My own FX5/5watt Luxeon has paused due to the last of encouragment to get a side emitting 5 watt Luxeon. I have a working setup but it lacks anykind of a beam and too much light everywhere.

 

[potholer]

I have a working setup but it lacks anykind of a beam and too much light everywhere.

Depending how much heat your 5W generates, having a standard wide-angle star firing sideways into half a reflector is worth thinking about. Comparing that method (which I use) with a mate's side-emitter, both running at ~1W, the beams are pretty equivalent in brightness and spread, though my method doesn't give much light above the horizontal, which means I need my wide beam for climbs up, but also means I can sit around with spot-beam on without blinding anyone as long as I point my light below their face.

Positioning can be tricky, but gets easier with practice. I couldn't be certain of the thermal implications with a 5W diode, but it is possible to glue aluminium plate onto the back of the star to at least circulate the heat inside the headset. If all you had was a star connected straight to the switch, (and possibly a ~1W emitter+resistor to give a wide pilot beam), maybe a chopped-down CPU heatsink could be mounted on the back of the 5W LED, in the space where I put the circuitry in my design?

You'd probably want a couple of old reflectors to practice on first, and something like a Dremel (or cheap equivalent) with a thin cutting disc for reflector butchery. A decent high temperature epoxy could be useful as well.

 

[Mike W]

"Annoying banding" is eliminated by good reflector design - the facetted ones, sometimes called 'dichroic' are excellent. Even the reflectors for side-emitters are often made this way.

I'm not sure about people being happy with moderate power lights. I often use a Petzl 14 LED Duo plus a Ring 1W side emitter. Although in small passages I run the Duo on low power, there are times when I'd like a more powerful spot beam - not all the time, just some vital times.

Personal bitch - I use loose NiMH AAs, for convenience,cost and environmental reasons. 2, or 4 are easy to charge, and I'm happy to carry 4, but a lot of nice LED lights run on 3 !!

 

[potholer]

The 'banding' I was referring to is the horseshoe-shaped bright band, caused by the off-centre positioning of a pilot light bulb in a regular headset layout.

I admit it'd be nice to have a 40-degree beam that was bright all the way across, but if it takes 16x the power that a 10-degree beam would take, for the moment, I'll stick with a relatively narrow beam, and move my head around a little more
There are some situations where more light would always be useful, but it depends how common those situations are, and what the cost is of having less light.

Not everyone *is* happy with moderate-power lights, but the fact that many of my users run at less than full power for much of the time does at least mean that some people are fine trading light for battery life, even on a light that's already fairly frugal at full power, and when batteries would last multiple trips.
I guess I (and some others) treat variable-power lights pretty much like carbides, and turn them down when the power isn't needed. Even running on recharagebles on short trips, where more light would cost nothing, I still
spend little time on full power. Turning the light up where necessary, I find it just isn't on full power very often.

Some modern smart chargers will cope with 1-4 cells, though personally I just charge 6 cells as 2s and 4s, and split to get 2 sets of 3, and manually discharge them individually before recharging to make sure they're all charged from fully flat whatever their history of discharge in use, and that seems to work fairly well.

 

[kay]

One thing I *have* noticed with my lights is that given a choice of two equally-powered beams, one a spot with some down-thrown light, and one a wide-angle with limited distance penetration, most people seem to use the wide beam much of the time, especially in narrow passage or crawls, where a spot beam can be an irritation.

I use the wide beam in crawls, not because the spot is an irritation, but because you can't always get your head to point in the direction that you want the light!

 

[potholer]

That's one of the advantages carbides, unfocused Luxeon LEDs, and even regular bulbs without reflectors have over regular 5mm LEDs - a wide, smooth beam that makes crawls (or climbs) easier to do without having to crank your head into awkward positions. However, if you have all-round light and a choice of a spot beam on *as well*, rather than instead, it can be annoying to have one bright spot where you don't particularly need it, and turning of the spot (even losing the extra light it gives outside the main beam) can make it easier to see overall.

 

[cucc Paul]

ive used just 3, 5mm leds in a speleo technics headset and found that if you use poor light for long enough your eyes just adjust, and everything is ok after 20-30m or so... although i've been on two trips now where its conced out although i think this is due to a serious lack of investment and maintenance so cant complain. Louis is your duo still mounted at some odd angle.

 

[potholer]

I used a 3-LED bulb in a Laser headset for a few years, first as a backup to a reliable carbide, and then as the main light in carbide-free N. Welsh caves.
Once eyes had adjusted, it was usable for getting around, but had no distance penetration, and definitely relied on night vision - other people's caplamps were relatively blinding, and colours could be rather muted.
A home-made multipower 7-LED unit was slightly better, but still lacked any kind of distance performance, and was patchy in colour rendition - some areas of blue, some of yellow, which made movement on uneven mud floors a little harder. There were various problems with the setup, but it was a good learning experience. Doing almost everything differently the next time round gave a pretty good result.