Maglite build, Questions on LEDs/Lenses

[semi]

Hi guys, been trawling through this forum trying to figure out a few things for a D-maglite LED build, but getting a little confused on a few points.

Probably best to start by saying what I want the light for- I currently have a UK SL4 eLED dive light, but for night diving I'm not too happy with the very narrow beam, and would like some more light than it gives (claimed 400lm).

So, I want to build a canister light with a better beam and more power/brightness. I have access to some machining and custom glass, but my problems are with LED and lens selection.

I've been thinking about using a single XM-L with a decent output, or possibly a combination of 2/3/4 LEDs mounted with lenses. I'm trying to get my head around lens configurations, but from what I gather, I have two options-

1- mount a single LED below the head on a heatsink, then use a single lens in the head itself
2- mount 1+ LEDs in the head itself, with individual lenses?

I'm not sure how the lens config will work with multiple LEDs, do they each have a small lens that can go over the top, or they sit in a mount with lenses over the top of each LED?

I'm trying to achieve a light with plenty of brightness, and a fairly wide beam (at least, wider than my UK, which has a roughly 1ft dia beam at 10ft). I'm not too sure if I want a little spill or not, hence I'm not sure whether to go aspheric. Can someone who's diving with them comment?

Can anyone help me to understand what's what, and possibly give a recommendation on configs?
Thanks
Semi

 

[350xfire]

OK, so you want a high power floody light? Try the Dealextreme 3XML module. You'll need to remove the diver and put in a Taskled but for a fully assembled module it's plenty bright.

 

[DIWdiver]

Personally, for night diving I like a light with a narrow flood and noticable spill, very wide. This lets me see stuff in a wide area, helping to notice more things and to prevent claustrophobia (not that that's particularly a problem for me, but I like to see my surroundings), while still having most of the light in a small area to light up what I'm focusing on. That kind of beam comes from a reflector, and one that's not deep. The light that hits the reflector gets focused into a "hot spot", while the light that exits the front without hitting the reflector provides the spill. The deeper your reflector, the more gets put into the hot spot and the narrower the spill gets, and vice-versa.

I couldn't find a 3-xml module at DX, but any of those type modules are also floody with wide spill. 3-xml or 5-xre or xpg will provide much more light than your UK, but remember that if you put 4 times as much light in a beam twice as wide, you have the same brightness over a bigger area.

Another option is a module with 3 or more LEDs and a single-piece multiple-lens optic array. These can provide better distinction between hotspot and spill than a crappy or shallow reflector, but not as good as a high-quality deep reflector. Several lenses are molded into a single piece of plastic, and a PCB is specially designed to match the optics. Ledil and Polymer Optics (maybe others) make the optics, and various vendors make PCBs. Cutter is a big name vendor in this area, though DX, LEDsupply, and others sell them.

It is also possible to mount several small individual lenses over several LEDs, but this is a lot more work, and you would need to have a very specific goal in mind before this might look better than other options.

I don't recommend aspheric lenses for night diving, because the spill is so tiny. In the daytime it's great to punch through murky waters and compete with natural light, but at night it gives you tunnel vision.

I'm now going to bed in my flame-suit jammies, as I'm sure others will clarify, add to, dispute, or even contradict what I've said.

D

 

[alpg88]

can't add much.,
diwdiver pretty much got it right, he dives so he knows what he is talking about.

what i would add thou, there is a chance that when you build your light, dive with it, you wont like the beam\hotspot\spill.. so my advice make the optics interchangeable, leds and lens holders can be permanently attached, but lenses can be removed, and swapped for wider\narrower. i use carclo lenses they have few different patterns, and all use the same holder. but other brands have such holders too.
will be a big disappointment if the beam turns out wrong, and lenses are permanently attached.

 

[semi]

Personally, for night diving I like a light with a narrow flood and noticable spill, very wide. This lets me see stuff in a wide area, helping to notice more things and to prevent claustrophobia (not that that's particularly a problem for me, but I like to see my surroundings), while still having most of the light in a small area to light up what I'm focusing on. That kind of beam comes from a reflector, and one that's not deep. The light that hits the reflector gets focused into a "hot spot", while the light that exits the front without hitting the reflector provides the spill. The deeper your reflector, the more gets put into the hot spot and the narrower the spill gets, and vice-versa.

This is what I've been thinking- A decently tight beam with high brightness with a bit of spill to help me see what's around me without having to point my light exactly at what I want to glance at. There's 3 XML reflectors from cutter electronics, here in Aus:
Cutter XM+Triple+Lens which is designed to work with this 3 XML module: Cutter XML Leds x 3 on 32mm MCPCB
-these are 32mm, would I be better off with one that's 50mm, to fit in my maglite head (which seems to be 50mm ID, from my slightly poor measurements), like this one from DX? Does it matter if the lens unit is smaller than the head, other than that it might move easier?
DX SKU 11922

I couldn't find a 3-xml module at DX, but any of those type modules are also floody with wide spill. 3-xml or 5-xre or xpg will provide much more light than your UK, but remember that if you put 4 times as much light in a beam twice as wide, you have the same brightness over a bigger area.

How floody are they? From looking into it, the UK seems to be 200lm for most of its life. I'd be pretty happy with a light that's about as bright as the UK (although I'd obviously prefer a bit brigher ) with a beam twice as wide and some spill. I still want something with a fairly defined beam. If I was to buy the 3xSML unit above, could i use it with a single lens if I decide I don't like the reflector module? I'm guessing I couldnt use it with a single, larger reflector?

Another option is a module with 3 or more LEDs and a single-piece multiple-lens optic array. These can provide better distinction between hotspot and spill than a crappy or shallow reflector, but not as good as a high-quality deep reflector. Several lenses are molded into a single piece of plastic, and a PCB is specially designed to match the optics. Ledil and Polymer Optics (maybe others) make the optics, and various vendors make PCBs. Cutter is a big name vendor in this area, though DX, LEDsupply, and others sell them.

It is also possible to mount several small individual lenses over several LEDs, but this is a lot more work, and you would need to have a very specific goal in mind before this might look better than other options.

I don't recommend aspheric lenses for night diving, because the spill is so tiny. In the daytime it's great to punch through murky waters and compete with natural light, but at night it gives you tunnel vision.

I'm now going to bed in my flame-suit jammies, as I'm sure others will clarify, add to, dispute, or even contradict what I've said.

D

Making a lot more sense to me now, thanks a lot. I don't have anything super specific in mind, so I think I might be happy with a lot of different results, but seems like I don't want aspheric- at least for now

Do not link directly to sales web sites - Norm

 

[semi]

can't add much.,
diwdiver pretty much got it right, he dives so he knows what he is talking about.

what i would add thou, there is a chance that when you build your light, dive with it, you wont like the beam\hotspot\spill.. so my advice make the optics interchangeable, leds and lens holders can be permanently attached, but lenses can be removed, and swapped for wider\narrower. i use carclo lenses they have few different patterns, and all use the same holder. but other brands have such holders too.
will be a big disappointment if the beam turns out wrong, and lenses are permanently attached.

Already my plan, thanks. I'm not really sure how wide/narrow I want the beam, so those lenses sound like a pretty good idea. Any idea where I can find them?

Also, if I mount the LED module on a heatsink in the maglite body, rather than in the head (assuming it fits), can I move the heatsink up and down to get the focus/tightness I want?

Thanks for the help, still getting my head around a few things, haven't messed with optics much, but very excited to get into it.

 

[alpg88]

they are sold at led supply, and illumination supply also has some. digikey has a lot of lenses too.
i don't see why you'd need to move heatsink, you wont have oem reflector in which you'd need to get led focused, if you go with tir lenses, you'll have a star with led on it, both sitting on heatsink, and lens holder sits on the star with help of few drops of glue, the lens will be in the holder, it pops in and out of it, so relative position of the sink in flashlight wont matter as far as focus goes. basically the heatsink with star\holder\lens is already focused light, maglite body is just watertight case for it

 

[semi]

they are sold at led supply, and illumination supply also has some. digikey has a lot of lenses too.
i don't see why you'd need to move heatsink, you wont have oem reflector in which you'd need to get led focused, if you go with tir lenses, you'll have a star with led on it, both sitting on heatsink, and lens holder sits on the star with help of few drops of glue, the lens will be in the holder, it pops in and out of it, so relative position of the sink in flashlight wont matter as far as focus goes. basically the heatsink with star\holder\lens is already focused light, maglite body is just watertight case for it

Oh, so is it a 3 lens holder, with individual interchangeable lenses? I thought you meant a single glass lens. Will have a look at those.

 

[alpg88]

no, individual holder\lenses, theoretically, you can use different optic in each led, if you got more than 1 (3 20mm lenses will fit in mags head) to adjust the pattern, but how it'll work in real world, or will it do any good at all, under water, i have no clue.

 

[semi]

no, individual holder\lenses, theoretically, you can use different optic in each led, if you got more than 1 (3 20mm lenses will fit in mags head) to adjust the pattern, but how it'll work in real world, or will it do any good at all, under water, i have no clue.

Not really looking for different lenses in the head, I think I will stay with the 3x reflector for now, and once the whole thing is sorted, then think about changing beams etc. I think the reflectors will give me the beam and spill I'm looking for, at least until I dive with it and figure it out.

 

[alpg88]

that is true, you never know until you try, or see someone else try.

 

[Packhorse]

I have a 3XML from DX. Its floody but not so bad. Probably good for night dives and wreck dives where you want to light up a whole room. Not so good for signalling or murky conditions.
You will need to machine the lip off the reflector.

Another option is a single XML and 44mm DX aspheric. Its a great combo in a Maglite.
less lumen but more lux.

 

[350xfire]

I have a 3XML from DX. Its floody but not so bad. Probably good for night dives and wreck dives where you want to light up a whole room. Not so good for signalling or murky conditions.
You will need to machine the lip off the reflector.

Another option is a single XML and 44mm DX aspheric. Its a great combo in a Maglite.
less lumen but more lux.

Agree!

 

[DIWdiver]

But he wants lux!

 

[Packhorse]

Nothing beats lux like a XRE over driven through an aspheric.

 

[semi]

Sorry, what's the difference between lumens and lux?

 

[wquiles]

Sorry, what's the difference between lumens and lux?

At a high level, without getting overly technical:

- Lux: Measure of the intensity of a light source onto a relatively small sensor area. If you have two lights with the same total output, the one with the more narrow reflector/optic (which concentrates more of the "energy" into a smaller area) will have the higher Lux reading.

- Lumens: A measure of the TOTAL light output, measured in a special 360degree fixture (called an integrating sphere). Two lights with the same total output, but with different Lux readings, will measure the same Lumen output in an integrating sphere.

Thus, if you want to know about the total output, you look at Lumens. For lights with a similar Lumen output, the higher Lux light will have a stronger throw.

Will

 

[semi]

At a high level, without getting overly technical:

- Lux: Measure of the intensity of a light source onto a relatively small sensor area. If you have two lights with the same total output, the one with the more narrow reflector/optic (which concentrates more of the "energy" into a smaller area) will have the higher Lux reading.

- Lumens: A measure of the TOTAL light output, measured in a special 360degree fixture (called an integrating sphere). Two lights with the same total output, but with different Lux readings, will measure the same Lumen output in an integrating sphere.

Thus, if you want to know about the total output, you look at Lumens. For lights with a similar Lumen output, the higher Lux light will have a stronger throw.

Will

Ah, thanks. I 'don't need the lux to be super high, at this stage I'd be happy with a reasonable lux over a decent area. Hence I don't really want aspheric, or to concentrate the beam into too narrow of an area.

 

[DIWdiver]

Sorry, meant to say "He wants lumens, not lux", but you've already cleared that up pretty well.

 

[beekeeper5]

I have a 3XML from DX. Its floody but not so bad. Probably good for night dives and wreck dives where you want to light up a whole room. Not so good for signalling or murky conditions.
You will need to machine the lip off the reflector.

Another option is a single XML and 44mm DX aspheric. Its a great combo in a Maglite.
less lumen but more lux.

I have DW's triple XM-L. It's bright, floody but lights up everything in sight. I sometimes think it's too bright though. I'm also thinking about the 44mm DX aspheric but I have to figure out how to mount it in a maglite without a lathe. Another option is to use the Cree 5 * XRE light. I also have one of those and it throws. Let me know if you want any beam shots.