Video Light Relfectors

Hi,

I thought I'd post the mk1 version of my video light solution.




LED: 6 * XMLS (3S2P)
Driver: TaskLED h6flex
Switch: Apem Prolongated Piezo
Power: 4 * 18650 (4S + PCM)
Dimensions: 60x60x140mm
Construction: Delring body + end cap, alloy head, 6mm acrylic lens.

Charging: It's a 'sealed unit', with charging done via the two port plugs in the rear. They're never removed, but rather are off the shell +/- contacts to the battery that run via a TaskLED Hallsw so that the charging circuit is normally open. It's yet to be built, but the plan is to have a charging disc/plug that aligns two male banana plugs into contact with the port plugs. A magnet (also in the charging disc) triggers the hall switch and the circuit is live. I've tested this successfully by hand, just haven't built the plug that makes it all pretty and houses the magnet.

During a previous thread relating to a piezo/driver issue, it was raised that my bare LED solution was losing too much light due to the lack of reflectors, optics, etc... I cited commercial examples of similar designs, such as the Gates, Light & Motion Solas, Fisheye LED, etc....

Test video with the mk1 solution is below (5 * XMLs @ 3000ma; 2 heads):


One suggestion was a domed lens would be the solution. After some basic research I've deemed this impractical for me, so have ruled it out.

Another comment was that too much light was being lost through the flat lens due to reflections (sideward or inward). To that end, before I assembled the this one I tested the light output both with and without the 6mm acrylic lens. The result was no visual difference in beam width or intensity (hitting a beige wall 4m away). It might be worth noting that with this build I putt some effort in centring the LEDs, versus spreading them around the edges.

The question I'd like pose is whether a DIY reflector that counter sunk each LED would have any value. My thoughts were to make this out aluminium, such that each LED would be exposed through a countersunk and polished hole in a faceplate (hope that makes sense). My theory is the countersunk hole will act as a reflector and push light forward.

I'm also keen to hear any other comments on the design, good or bad as this is the prototype of sorts and I plan to make a batch of them for some cave/wreck projects.

Nice.
Very nice.

I am about to build a 6x XML video light ( two light heads with 3 XML's each).
While I will not be using a flat lens ( Acrylic tube) I will also not be using any reflector.

So...Bare XML's have a beams angle of 120 ( or is it 150?) degrees.
Sure you could add a reflector to get a higher lux but then you get hot spots.

But then you must also consider the lens that is being used on the camera and what angle it is viewing.
Also consider that dual light heads can help increase the beam angle by pointing them at different angles.


Ideally I would like to use LED's with a 90degree beam angle like XR-E's
Sure XR-E's are less efficient than XM-L's ( or XP-G's) but the 90 degree beam angle works for them in this regard and depending on the cameras lens may in fact be better.
Buit then you must also take in to account other factors like the driver and how many LED's you can fit in a given space.

One suggestion was a domed lens would be the solution. After some basic research I've deemed this impractical for me, so have ruled it out.

Click to expand...

Keldan lights are known on dome , honestly I don't know how big is difference on video/photo.

http://keldanlights.com/english/products/underwater-video-lights/index.html?ridcat=14

lucca brassi said:

Keldan lights are known on dome , honestly I don't know how big is difference on video/photo.

http://keldanlights.com/english/products/underwater-video-lights/index.html?ridcat=14

Click to expand...

Those keldans are reputed to be some of the best, which is why I took the dome comments seriously. The other factors for the Keldans are matte wide beam and high CRI, though at a cost of USD$2000 each they'd want to be good.

Since I shoot video with my DSLR, I'll be using an ultra-wide to fisheye lens for wreck and cave shooting. Field of view is 90-140 degrees horizontal, but up to 180 degrees diagonal. Underwater I'm getting a beam angle of 110-120 degrees horizontal, so I'll need two lights to adequately light my frame when using a fisheye. One light fills about 95% of the frame whilst in wide mode, but not full fisheye. In this case, I'll get mostly overlapped lighting and intensity

I actually made 3 mk1 head (see below). One head with XML T6's and another two with T4's. Now I'm aware the cooler bins have more light intensity, and I can notice this between the two head versions though it's not that noticeable in terms of camera exposure. In the 10-14mm boards, Cutter only seem to sell the XMLs in T4 4200K or T6 6000K. I'd like a 5000K though I don't think this is material in terms of light output.

Damn ! thats quite a lot of good work

i dont own a quality video camera, nor i know someone owning one, so i lack a bit of knowledge on this area...
never the less, i did built two D Mag head with one SSt90 each, in serie together, direct driven on 5Ah lipoly 2cell.
the can only have a toggle reed actuated by a magnet in the glove.

for now, i have one dive done with 44mm aspheric wide, and the overlap of the two lamps is verry visible.

I've looked on Kaledan light spectrum and it is very intensive in yellow and red section . It looks they use luminus leds probably http://www.luminus.com/products/datasheets/Luminus_CSM-360-W_Datasheet.pdf or http://www.luminus.com/products/CBM-360_2_2810479040.pdfhttp://www.luminus.com/products/datasheets/Luminus_CSM-360-W_Datasheet.pdf. (at least at LUNA 8-LH )


I have checked that led http://www.luminus.com/products/SSM-80_2_2300787465.pdf which spectrum looks ''warm'' may be ''interesting'' ?

Nice analysis of the kaledan. Very interesting to see they use a very warm LED, which is what I like for video. It surprises me that a lot of video guys claim religiously that 5500-6000K video lights are the best, which supposedly is to match the sun's colour. To me though, lighting in that space even when custom whitebalance is set (underwater a least) seems very cold and leave unpleasing skins tones (wreck rust and cave walls look cool too).


I was planning my next build to use XML T4 5B bin, which are 4200K.

I'm also considering the switch over to 10mm round MPCBs, and going to 9 * XMLs. The battery wouldn't last long with all 9 at 3amp, but I should get much more usable output on the low and medium levels. I should be able to fit 9 * 10m boards, instead of the 6 * cut down 14mm.

Where would I buy a charging port
For a custom dive light? Worried about opening the canister too much......

johnnyryan said:

Where would I buy a charging port
For a custom dive light? Worried about opening the canister too much......

Click to expand...

One commercial option I found on my travels was to use e/o wet connectors. Unfortunately these are rather expensive, as you need the bulkhead adapter, blank plug and cable. Dive-xtras.com had the beat pricing i could find.

The form factor was too big for me so I went down a DIY path.

Here I've used two standard lp port plugs to provide conductivity through the housing, which go to a taskled hallsw, and then the battery. The circuit is normally open so electrolysis won't be an issue.

To charge, I connect two 4mm male banana plugs into the port plug Allen key sockets. They fit ok, just aren't as deep as I'd like. A magnet then flips the hallsw and charging begins.

Now I'll preface this with the fact that this design is a theory which I've tested on the bench and assembled but not used for any long period in the field.

Seems to work a treat thus far, is cheap and very simple!!

Thanks for that. Great idea!! I'm limited with space so was thinking about a screwcap with a direct socket to the battery. An old torch I have has this and works great. Not sure if something like this can be bought off a shelf though........
Anyone seen one?

To charge, I connect two 4mm male banana plugs into the port plug Allen key
sockets. They fit ok, just aren't as deep as I'd like. A magnet then flips the
hallsw and charging begins.

Click to expand...

just an idea DIY in that way

http://www.impulse-ent.com/pdfs/71-95/80Mag_Op_Prox_Switch/80.IESQ4SW.pdf

switch is integrated in socket and magnet in the plug

Some great ideas there guys. Thanks. I'll mull over it and see what works. Just wish my components would arrive!!!!

lucca brassi said:

just an idea DIY in that way

http://www.impulse-ent.com/pdfs/71-95/80Mag_Op_Prox_Switch/80.IESQ4SW.pdf

switch is integrated in socket and magnet in the plug

Click to expand...

Any idea of where to get them and reliability?

Just an update on the video light project. I built 3 new mk2.5 version, with 9 * XML T5's and am much happier with the output and burn time. Beam angle is much the same at ~100 degrees in water. I also made the units slightly larger to make assembly easier (it was a little tight in the prototype). The alloy heatsink is also 5mm long as 6 * XMLs get hot, but 9 gets notably hotter even at 2200ma and not 3000ma. In moving water heat isn't an issue, though I've run tests in a bucket and it ends up like bath water, but the 90 degree trip point has never been hit on the h6Flex.

We also successfully used the prototype in 125m of water, and it worked flawlessly. It's actually nice to know the 6mm acrylic front can handle that kind of pressure as it makes is a vaiable design pattern for primary light heads too.

I'm using the same H6flex driver, but running at max output. Burn times:

hi: 33min
med: 61min
low: gave up at 90min

Hi Damien,

Nice light!! It's near 9000 lumen!!!! for a total of 27.000 lumen with 3 of them!!!! Is it enough? I do hope so.

I send you a PM.

Best regards from Zaragoza

Hi Damien,

Would you be so kind to give more details about you lights?

How did you prepared the battery pack? It's custom made or did you buy it some where already made?
There is no troubles having 6.6A out of the batteries. I suppose that you are using the same pack than in the first version, isn't it?

I've been looking for a pcb for this amp rate and cannot find nothing small enough.

Would you be so kind to explain a bit more how did you wired the wet contacts? Not sure about how to do it.

Thanks in advance for your help.

Best regards from Zaragoza

herculino said:

Hi Damien,

Would you be so kind to give more details about you lights?

How did you prepared the battery pack? It's custom made or did you buy it some where already made?
There is no troubles having 6.6A out of the batteries. I suppose that you are using the same pack than in the first version, isn't it?

I've been looking for a pcb for this amp rate and cannot find nothing small enough.

Would you be so kind to explain a bit more how did you wired the wet contacts? Not sure about how to do it.

Thanks in advance for your help.

Best regards from Zaragoza

Click to expand...

Happy to.

Battery - I'm using 4 * Tenergy 18650 /w tabs (4S), which I assembled myself. I first tried to use this PCM from Batteryjunction.com, as the first version of my light ran at 6A forward, but was only drawing 5A from the battery to the h6flex. In any case, it cuts out when loaded with anything over 3A so not something I'd recommend. I then got some PCMs off K-lite which had an 8A rating, similar issue though as cut out at around 5A. In the end I had to bypass the PCM for power draw, though still use it for charging the pack. I plan to fix this eventually but didn't have time before my US trip where I need the lights. I put a fuse in to protect against a short and the h6flex provides under voltage protection.

I would have much preferred to buy a battery pack as I hate building packs. I could only find one 4S 18650 pack in the quad/square pack configuration I needed at batteryspace. The only proba with that is the shipping to Australia is ridiculous, and it's only rated to 4.2A anyway.

The Tenergy batteries I'm using seem to do the job nicely, and are rated to max 10A discharge I think. I'm only pulling about 5.5A, so well under this.

The charging contacts are a relatively simple affair, and so far have worked flawlessly (I'm quite chuffed with it). Basically I've just used standard LP first stage port plugs as conductive contacts through the housing. I drill a small shallow hole in the back side of the plug (~1mm) to remove the chrome so that I could solder wires to the brass. Each is wired to the +/- of the battery via a TaskLED Hallsw, which by default is 'normally open' making the contacts inert. If they're live in water I presume you'd have some serious electrolysis happening. Although the Hallsw is designed to be a draw switch, it seems to work perfectly as a charging switch. So to charge, I've made up a little jig that holds the male banana plugs and a magnet. The port plugs accept the banana plugs in the allen key socket well enough (it's not perfect), but you only need a minor connection for it to conduct power. The magnet enables the contacts and you can now charge the pack.

Another gotcha I hit was the fact that I use iChargers to charge all my batteries. They don't work real well with the PCMs in the packs, as when the low voltage trips the pack, the pcm needs to be 'kick started' by the charger and the iChargers are a little to smart for the own good here. They try and detect battery voltage, and since the PCM has cut power to the terminals it errors. The work around I've used to simply use the 'Nimh forming charge' mode on the iCharger for a few seconds, this kick starts the PCM and then I switch back to Lipo charging and it's happy to charge the pack like normal. I'm told that the higher end Turnigy balance chargers don't have the PCM issue, though don't have any myself.

Hi Damien,

Thanks for your answer, I thought you pass me out:wave:

I'm still looking for a PCB for the pack, and will take a look to this batteries you are using.

I found a couple of them that will do the job but are too big, I would like to have a PCB with equilibrium capability so I don't need a special charger.

If I'm not wrong you can use a normal DC adapter to charge the battery pack, I mean you don't need a special charger, didn't you?

I'll keep studying that, I post in the battery section of the forum looking for some advice.

I'm also considering on a 5s pack, I'll contact George (Taskled) to find out if it's a good idea or not. Just looking for a bit extra time.

I don't understand well how did you connect the wet contacts. I'll read more carefully the tech docs of Taskled and your answer and let's see if I'm able to find it out.

I'm planning to use a hallsw also to control the driver, it's much cheaper, I like more the piezo switch but I cannot find anyone for less than 25-30€. I keep looking, may be I'm lucky and find a sale somewhere.

Thanks again for your help.

Best regards form Zaragoza

Very nice build!

I'm currently working on a canister version with a small head 6 - XP-G.
I'm shifting to the warmer spectrum and higher CRI 90+ output this time around.