Canister light build. Need input.

[kallehornstrom]

Hi
I'm embarking a project involving 4 ostars and some $$$ to build a light similar to this: http://www.tauchfunzel.de/ostar1_en.htm
I'm also aiming for 5h burn time so the canister needs to be rather big. Both the canister and the head will be ordered from here:
http://shop.strato.de/epages/61162903.sf/de_DE/?ObjectPath=/Shops/61162903/Products/%22G%20LK%2050N%20AL%20(Set)%22
http://shop.strato.de/epages/611629...th=/Shops/61162903/Products/"G AT 115 250 AL"

the pack is going to be made up of 20 nimh D's wired to 12V (I figured 12v is the best way to go in case I wish to use it with another head).
I will not make my own driver board (as Mike did) so the question now is what driver options do I have?
I also need to get my hands on a suitable charger. Any ideas are greatly appreciated.

/Kalle

 

[Packhorse]

How much thought have you put into this?

Do you just want to build one of the brightest dive lights out or are you more interested in building a really good dive light. They are miles apart ( IMHO)

*4 Ostars will result in a floody beam when crammed into a small head. Even when "tightly" focused
*20 "D"s is going to be huge!
*Parallel NiMh's dont charge well

 

[kallehornstrom]

Well, first of all it needs to be durable - that is; functional for 10+ years. A lumen output of 2500+ is what I'm aiming for but of course the light needs to be focused into a tight beam.

 

[Packhorse]

Why 2500 lumen?

What do you define a tight beam as?

I doubt your batteries will last 10 years if you charge them as a parallel/serries pack.

The LED's will be out of date in 2 - 3 years tops (perhaps sooner like by the time its built). Mind you thats OK. Just design it so the LEDs and optics can be changed.


I heard somewhere that many DIR cave divers consider anything above a 21w HID overkill. Thats about 1700 "produced" lumen. My 1000 odd lumen light is very comparable to a 21w HID and I would agree that much more is a waste.

What sort of diving do you do?

 

[Goldigger]

All technical politics aside, i stumbled on this 4 ostar lamp build found on http://www.tauchfunzel.de/ostar1_en.htm some months back..You have to admit its a work of art.

Mike did use reflectors and optics to solve the floody beam problem.
The electronics is one pcb with 4 drivers, 1 for each ostar..

If you want the brighest light out there go for it..at least we can all use your light and save on batterys..

 

[kallehornstrom]

Why 2500 lumen?

What do you define a tight beam as?

Less than 10 deg. I'm prepared to test different optics.

I doubt your batteries will last 10 years if you charge them as a parallel/serries pack.

I give you that. Perhaps you can suggest a different battery setup. (Although I don't expect the batteries to last forever).

The LED's will be out of date in 2 - 3 years tops (perhaps sooner like by the time its built). Mind you thats OK. Just design it so the LEDs and optics can be changed.

Yes, that's what I had in mind when deciding on these expensive yet rugged housings. My plan is to avoid permanent attachements by glueing, soldering or welding.

I heard somewhere that many DIR cave divers consider anything above a 21w HID overkill. Thats about 1700 "produced" lumen. My 1000 odd lumen light is very comparable to a 21w HID and I would agree that much more is a waste.

What sort of diving do you do?

Well, close to my home the waters are murky (light needs to be adjustable) but I also go to Norway for wreck diving on a couple of occasions each year where the water is clear. I also plan to take a cave diving course and hopefully dive some of the mines here in Sweden.

What it all boils down to is having a light which I can be satisfied with for many years to come.

 

[Packhorse]

k..You have to admit its a work of art.

For sure. Its very well designed and constructed, I just dont think its very practical.

Well, close to my home the waters are murky (light needs to be adjustable) but I also go to Norway for wreck diving on a couple of occasions each year where the water is clear. I also plan to take a cave diving course and hopefully dive some of the mines here in Sweden.

What it all boils down to is having a light which I can be satisfied with for many years to come.

Then I think this light is totally wrong for the conditions you dive in.
In murk it create nothing but back scatter and blind you. Imagine driving in thick fog with your headlights on full.

In a cave/mine/wreck you want to be able to have clear communication with your team. This is done by use of light signals. Wide beams are very ineffective for use as signalling lights.

IMHO 10 degrees is actually a wide beam for a dive light. Perhaps 10 is OK if you get all the light inside that 10 degrees but you wont unless you use aspherics which dont work well with multi die LEDs.

 

[herulach]

Saying nothing about the output (although maybe 1 P7 with a big ish reflector, and 3-4 R2s with good lenses/reflectors would probably (i'm not a diver) give you a better beam and a comfortable 1300/1400 lumens)

You might be interested in george's (taskled) new hyperboost driver he's announced in the bike forum:
http://www.candlepowerforums.com/vb/showthread.php?t=242634

 

[kallehornstrom]

For sure. Its very well designed and constructed, I just dont think its very practical.

Then I think this light is totally wrong for the conditions you dive in.
In murk it create nothing but back scatter and blind you. Imagine driving in thick fog with your headlights on full.

Yes, the light would surely be too intense in murky waters but that is why it needs to be dimable. Perhaps I which to use it for other applications in the future - like video footage? (just speculating)

I'd appraicate of you could give me insight into what you are considering to be the best light for diving in both murky and clear waters?
I'm totally prepared to revise my plans but I'm likely to stick with the alu-canisters.

 

[Packhorse]

Its not that the light would be too intense, its that it would have too much flood. Dimming it down will just reduce its "punch" through the water.


My preferences for dive light designs are well documented. Check out some of my threads like this one

What you are looking at building may very well be a fantastic video lighting system.

 

[kallehornstrom]

Its not that the light would be too intense, its that it would have too much flood. Dimming it down will just reduce its "punch" through the water.

So you say the ostars can't be focused enough. That's a bugger! But I guess the upside is that I won't have to caugh up as much $$ for the emitters.
What do you reckon the best emitter (beam wise) is?

 

[wquiles]

So you say the ostars can't be focused enough.

Packhorse is absolutely right - those Ostars can't be made to focus as well as smaller, single DIE LED's. A large part of the problem is in fact that they are multi-die and fairly large, which prevents a tight focus and small image. You can achieve fairly decent trow and a "narrower" beam with a very large reflector, like the 3" diameter reflector one I used here in this build, but I would still call this a fairly wide beam - not even close to the narrow beams can get with an R2 and an aspheric lens:
http://www.candlepowerforums.com/vb/showthread.php?t=192304


Will

 

[Packhorse]

Its not just the ostar but all multi die emitters that have this problem.
And as Will points out to get a decent tight focus you need a large reflector.
Thats not to say you cant get a decent result with a multi die and a large reflector or a singe die and a small reflector, its just not optimal.

I guess this is why I am such a fan of aspherics. But they too have their problems. Efficiency being a big one.
I built a IST aspheric for a customer 200-250 lumen (R2) he had access to the ability to measure the torch lumen and claimed it was only 90. He still claimed it was one of the best throwing lights he ever owned though.

There are now a few new LED's on the market since I started building my aspheric based can lights. XP-G and SST-50 come to mind.
Problem with these is the die of the LED is larger so the beam will be wider. With careful selection of apherics it may not be a problem though.

Im not saying you should build an aspheric based light but you should consider it.

 

[kallehornstrom]

Thank you all for the input. I think I'm starting to revise my original plan. One concern is that the light head I had in mind can only hold 4 led's mounted on boards. I guess using bare emitters is not an option since four lenses will consume the space anyway?

 

[Linger]

he had access to the ability to measure the torch lumen and claimed it was only 90.

Those must be Surefire lumens

 

[kallehornstrom]

Could this be somehing?: http://www.candlepowerforums.com/vb/showthread.php?t=208754

To fit 7 xr-e's into a 50mm housing would require the lenses to be cut down to around 16mm, much Packhorse like did: http://www.candlepowerforums.com/vb/showthread.php?t=235443

Using a blue shark driver really appeals to me since I could use an external pot (with breaker) and possibly control it by the rotary magnet fitted to the housing.

 

[kallehornstrom]

Any pros and cons with cutting down the lenses?

 

[Packhorse]

Well 1st off there is no way you will fit 7 in a 50mm light head.
4 is a squeeze in a mag. The more you try and fit in the smaller you have to make them and the less efficient they will be. Not to mention how hard it is to align them all.

You could cut them down using a grinder but I use a lathe. You will also need to make spacers for the lenses so they sit at the right hight from the LED. Once again a lathe comes in really handy.

 

[kallehornstrom]

Thanks Packhorse.
I saw that the xp-g's are on pre-order now so I might go for 4 of those. Although I found this at cutter: http://www.cutter.com.au/proddetail.php?prod=cut933
Optics designed to fit the 40mm 7 xp-g board. What do you think? Could it be worth a try?

 

[Packhorse]

Well that depends on what beam you want and what beam it produces. My guess is that it would have lots of spill.
I wonder when the XP-G's will ship?