Tiny high powered led for lighting sculpture - any ideas?

Hi all

This is my first post to the forum so hello to all you forum folk!

I play a lot with lights (with very little tech knowledge though). I make thousands of lantern lights for parades and various bespoke (shonky) lights for my long exposure light painting photos. However I have become stumped with a project I have on at the minute…

(All the ramblings below add up to this: I need a 500 (ish) lumen 1 smd light source in order to cast strong crisp shadows. Ideally something I dont have to build myself)

The project:
I’m making laser cut steel panels with botanical designs cut in to them. These will be sconces/shades fixed to an exterior wall through which I want to shine a light so that the cut out pattern will be projected on to the floor. Essentially they are big steel lampshades, likely to be around 60cm x 40 cm. They will be around 10-15cm from the light source.

The link below will show you an example of the effect I’m trying to create. (Couldn’t hotlink and show it here for some reason)

https://lh3.googleusercontent.com/KK…4-h930-tmp.jpg

My problem:
I need the smallest pinprick of light of the highest lumen output in order to cast a crisp shadow. It needs to be suitable for exterior use too. There are many light sources that will give me a blurry shadow, but very few that make it crisp. It really needs to be a tiny, naked light source, as far as I can tell. I would love to find some off the shelf product that would suit, but would also consider building something - or working with someone experienced who could make something bespoke for me.

Close, but no cigar:
The closest I have to a solution is this:

It’s a festoon bulb to fit car number plates or reading lights. It claims to be 250 lumens and is in fact incredibly bright. The tiny single emitter means that there is almost no blurring of the shadow on the floor. I can house it in a waterproof case and use standard car bulb fittings.
However, I need a bit more oomf! I think that I could really do with 400-500 lm.

The only things that seem to be able to do the job are the cree xlamps. However I can’t seem to find that in any consumer product (such as a car bulb) as a single smd.

What I’ve tried:
Cheap chinese Creee Q5 torches give me quite a nice light and crisp shadows, but I obviously cant hook this up to the mains.
0.5w strawhat led. Perfect light - way too dim
10w COB floodlights- Perfect brightness. Weatherproof. Unfortunately, they cast a fuzzy shadow.
3030 superblock 1.4w 120 lumen module. A bit fuzzy and a bit too dim.

Can anyone help with a solution or suggest alternatives?

Any help of any sort would be much appreciated.

Thanks in advance :slight_smile:

Andy

What about using a reflector as well so light isn’t bouncing all over the place? You could set up a wide angle to cover the area where the cut outs are but it ensures that light isn’t bouncing around elsewhere.

Itsonlyme - thanks for your suggestion.
My limited experimentation with reflectors has left me with blurred edges to the shadows, even though it throws more light forward. It’s as if the light is coming from a much broader source. The pin prick of light gives the crispest beam.
I wonder if some combination of lenses might work, but that’s beyond my ken!

Where are you in the UK?

As you have mentioned, you need a point source for the light. A reflector or lens won’t help.

Best choice is probably something like a CREE XPL HI LED run at 2-3 amps mounted on a heatsink and attached to a power supply to allow it to be plugged into an outlet. Depending on how many amps you run it at, you could easily get 500-1000 lumens.

I’m in Newport, South Wales. Not the nice one :slight_smile:

I see no problem taking a flashlight with a really short reflector and replace it with a spacer.
Or one to replace a lens with glass.

This one with the lens or a glass should be OK.
http://www.gearbest.com/led-flashlights/pp_394637.html?

You can drive the light with a buck driver like this set to 4V, or replace the driver with this set to 1.6A for 500Lumens

Thanks Firelight2. That’s pretty much what I’ve gleaned from scouring the RS catalogue. I suppose I was hoping for some existing ready made solution that would fit the bill.
The lighting feature is to be mounted externally on a nature reserve visitors centre wall. It’ll be eventually wired up by a registered electrician, but I’m wary of dabbling with leds/electronics that are way out of my experience for something that’s going to be in the public realm.
Is there anyone you could recommend who could provide/build what I need?

Thanks in advance.

Thanks Lexel. Those links are interesting. I’ve wondered if adapting torches might be a possible solution. I’d probably be driving 5 or 6 of these in total, so am assuming that I can just do the maths and get a driver that delivers enough power to each for my needs.
Weatherproofing is my other concern, but I’ve seen some ip67 cases that may work.

There are two options for tiny and bright:

1) Cree XP-E2 ‘Torch’
When driven at 2.2A (it can not be driven much higher) and well heatsinked, it puts out 500 lumen when dedomed. The led with dome is the same size as the led in your picture above, but it can be dedomed what makes it an even tinier source for even crisper shadows.

2) Osram Oslon Black Flat
Driven at 3.5A it puts out 700 lumen. The led is already without dome, exact the same die size as the ‘Torch’

Leds do not come tinier at the moment. There is the Cree XP-C that is smaller but is comes nowhere near 500 lumen.

Now you need soneone to make you the light, I have no time for a while, but perhaps someone in the UK?

Nice one djozz.
I’m so happy to have found this forum and be getting some solid leads. This has been doing my head in!

500 or 700 lumen would be the business. I’ll investigate. Thanks.

I see no problem in sawing off the back of a torch solder wires on the driver and fill it with hot glue.

The light color should be more warm, cold or neutral?

Another solution might seem a little odd but should work well.

http://www.kaidomain.com/p/S024418.Cree-XM-L-T6-Neutral-White-5000K-5500K-with-18mm-x-18mm-Aluminum-Base
Or
XPL will be a little sharper
http://www.kaidomain.com/p/S024472.Cree-XP-L-HI-V2-Neutral-White-4500K-LED-Emitter-with-KDLIGHT-3535-20-20mm-x-1_5mm-DTP-Copper-MCPCB


Take a proper heatsink, use thermal glue to get the star on it.
Use glue to seal off the 4 sides of the LED and the solder pads.

This one should be big enough.

Use the Buck driver set to 1.5A per emitter, you can wire all emitters in series if your power supply provide >4V per LED.

Dedomed Cree XPG2 or XPE2 might be an option for very small emitters, but not something for a beginner, need to reflow on DTP for the XPE2

If you cen get dedomed Emitters you need to seal em with polyurethane clear coat.

I forgot to mention that to get the mentioned performance, both leds need soldered onto a so-called DTP ledboard, which gives ultimate heatsinking. Make sure that your builder uses them! The Oslon officially does not fit the most used XP-type boards but you can succesfully solder them on there anyway.

Been sitting here casting shadows of my hand on the ceiling…

You need an unobstructed light source. No lens no reflector to get a crisp shadow at that short 10-15cm distance.
What we call a zoomie flashlight comes close but not at the short distance. I now tried a flashlight with no lens and no reflector and it casts a nice circle of light and has very crisp shadows of my hand on the ceiling, closer and further away than your requirements. You should be able to get it close to just the size of the steel plate.

Perhaps take the glass and reflector out of the 10W flood and see what happens. I have a couple 12V 10W in warm white here if you need me to give a try. No cool white on AC current here at home.
I think the fuzzy shadow is from the glass reflecting back on the reflector and mimicking multiple light sources. If it works and you need brighter go with 20W. These lights are over rated so even a 20W is only about 13W actual.

Aha! I have someone doing exactly what I seem to spend hours of my life doing! I spend a huge amount of time shining lights through my peg basket. Flashlights with no lenses definitely give the right effect.
I did pretty much dismantle the 10 w flood to see what was making it blurred. I think it’s just the width of the array itself (is that the right word?). It’s not in front of me now but I think it’s about 10 mm squared or so. That’s just too broad at the distances I’m needing.

The XPL HI emitter is about 2x2mm
To get 500 lumens you need about half the max current of it driving at 5W

Just look at 4500K color so the light is a decent daylight or warmwhite ones

I am pretty sure it will be well enough, no need to go for an 1x1mm XPE2 overdriven

If it helps anyone: this reflector-less kind of light is commonly called a “mule”. I’d have my C8 like that, but without the reflector there’s nothing holding up the lens, and I’m not a fan of such blatantly-vulnerable hardware :confounded:

quick test

dedomed XPG2

15cm from LED to 10mm hexagon plate
Beam distance to my ceiling 1.7m

XPG2

20cm from LED to 10mm hexagon plate
Beam distance to my ceiling 1.7m

Test with XPL HI

20cm from LED to 10mm hexagon plate
Beam distance to my ceiling 1.7m

Test with XPL HD

20cm from LED to 10mm hexagon plate
Beam distance to my ceiling 1.7m
with reflector only the spill is useable

Test with XHP35 HI

20cm from LED to 10mm hexagon plate
Beam distance to my ceiling 1.7m

XPG2 dedomed and XHP35 HI
the XPL and XPL HI are in the middle of that sizes

I would just buy a BLF A6 for $27 and unscrew the head like this:

It has 7 brightness-es to choose from up to about 1600 lumen.

Thanks Lexel, I really appreciate your help. That sounds good.
Is that easy enough for a novice to put together do you think, or should I find someone experienced to put it together for me?

Edit…

I’ve just noticed the other posts and the photos. Thanks for all the effort, that’s fantastic.

Cheers everyone else too. Lots of stuff to consider.