SST-90, 9A, Aspheric Primary Light

[betti154]

I'm in the midst of a challenge with some mates, which is to build the most evil primary light imaginable. It should have the tightest beam, with the most intensity. At a minimum it needs to destroy a 50w HID primary.

From what I've seen, a SST-90 at 9A with aspheric lens will do this. I know very little about aspherics.

Ideally I want to make the head as small as possible, though can any confirm:

• A good aspheric lens for this job? I've got some el cheapo aspheric lenses from dx (52mm and 28mm), though I suspect there may be better out there.
• As I'll be machining the head to match the lens, size is a factor as I can't work any material bigger than 70mm OD on my small lathe. Does big = better when it comes to aspherics?
• Distance between LED and lens, is this just trial and error or is there science to it?
• Water and the aspheric, I assume that water cannot hit the domed aspheric, and that a second lens must be seal the housing. ie. keep the aspheric dry.

I'll be driving it with this sucker. http://www.candlepowerforums.com/vb/...-SST-50-SST-90

Power source will be a 5S2P 18v 5.2ah lipo pack, simply because I have batteries lying around from a few video solutions.

regards, damien

[Packhorse]

I dont think you will hit 50w HID territory with a SST-90. In fact I know it.
I have a SST-90 driven at 5 amp in a deep smooth 35mm(+) reflector and it gives a nice tight beam. But its 21w HID territory. Driven a bit harder and it may surpass a 21w HID but doubt it would surpass a 35w HID.
Lets not forget that HID's and LED's produce different light beams though so direct comparisons are not really fair.

I also have a SST-50 behind a 44mm DX aspheric. While it has a larger beam than my other light the lux value is pretty close. It has no spill light though which is a pro or a con depending on what conditions you dive. I prefer it for most of my diving, but I guess for night dives or wreck dives in high vis water I would probably use the reflector based light.

Now if you want a tight beam light that comes anywhere close to a 50w HID ( not that I have ever seen one) I would suggest you use the biggest aspheric lens with the shortest focal distance and a SST-90. You may match the lux but you will not match the lumen or have anything in the way of side spill light.

The other approach is to use a ship load of XR-E's ( best LED to use with aspherics) with smaller aspherics. Ahortons 28mm ones work great but you would need 7 at least meaning that the light head internals would have to be 54mm at least ( in practice more like 60mm). Using this approach means you could defocus one ( or more) for spill light.

To answer your other questions.
Look at what others are using for aspherics. I like the DX44mm aspheric but I am sure there are probably better ones to be found in that size, and the Ahorton 28mm which kicks ass over the DX 28mm lens.
The shorter the focal distance the closer the LED can sit to the lens which means more lumen is gathered by the lens. This is very important.
The larger the lens the smaller the projected image ( generalisation).
The higher the quality of the lens the better the image will be ( IMHO not all that important at all).
Yes you must have a flat lens in front of the aspheric to keep the water off.

[betti154]

Thanks Packhorse, good stuff there to investigate.

Now I wasn't kidding when I said I need this light to be stupidly bright, offensive is another word that comes to mind. Burntime is certainly a secondary factor.

Can I put multiple (eg. 3 SST-90's 20mm stars) behind a single aspheric or would each need to to be paired with an independent aspheric lens?

[Racket]

.

Can I put multiple (eg. 3 SST-90's 20mm stars) behind a single aspheric or would each need to to be paired with an independent aspheric lens?

See here http://www.candlepowerforums.com/vb/...-with-Quad-led

[nwbrewer]

I dont think you will hit 50w HID territory with a SST-90. In fact I know it.
I have a SST-90 driven at 5 amp in a deep smooth 35mm(+) reflector and it gives a nice tight beam. But its 21w HID territory. Driven a bit harder and it may surpass a 21w HID but doubt it would surpass a 35w HID.
Lets not forget that HID's and LED's produce different light beams though so direct comparisons are not really fair.

I also have a SST-50 behind a 44mm DX aspheric. While it has a larger beam than my other light the lux value is pretty close. It has no spill light though which is a pro or a con depending on what conditions you dive. I prefer it for most of my diving, but I guess for night dives or wreck dives in high vis water I would probably use the reflector based light.

Now if you want a tight beam light that comes anywhere close to a 50w HID ( not that I have ever seen one) I would suggest you use the biggest aspheric lens with the shortest focal distance and a SST-90. You may match the lux but you will not match the lumen or have anything in the way of side spill light.

The other approach is to use a ship load of XR-E's ( best LED to use with aspherics) with smaller aspherics. Ahortons 28mm ones work great but you would need 7 at least meaning that the light head internals would have to be 54mm at least ( in practice more like 60mm). Using this approach means you could defocus one ( or more) for spill light.

To answer your other questions.
Look at what others are using for aspherics. I like the DX44mm aspheric but I am sure there are probably better ones to be found in that size, and the Ahorton 28mm which kicks ass over the DX 28mm lens.
The shorter the focal distance the closer the LED can sit to the lens which means more lumen is gathered by the lens. This is very important.
The larger the lens the smaller the projected image ( generalisation).
The higher the quality of the lens the better the image will be ( IMHO not all that important at all).
Yes you must have a flat lens in front of the aspheric to keep the water off.

Which reflector are you using with the SST-90 that give a nice tight beam? I'm not all that fond of my aspheric for night diving.

[Packhorse]

I use a ultrafire W300 as a light head with its stock reflector.


NO you cant use multiple LED's with a single aspheric. The LED must be centred to the aspheric.

[betti154]

thanks.

Since I've got the SSt-90 + driver coming I think I'll play with those and the 28mm and 50mm aspherics I already have. I"m wondering if 3 * 28mm aspherics with 3 * SST-90's might get where I need to be in a small enough package.

[DIWdiver]

I think the SST-90 behind a 28mm lens is not going to give you a very tight beam. I've been playing with an SST-50 and an XML, and some 30mm aspherics. At the same current, the XML gives a noticably tighter, brighter beam, and if defocussed to the size of the SST-50, a much more uniform beam and slightly better brightness. Of course, the '50 can be driven much harder.

Oddly, they both give noticable spill. I'm thinking this is due to light bouncing of the lens mount before going through the lens. I kind of like it. The lens mount is just a hunk of wood I bored a hole in to hold the lens.

The '90 would give you a big bright beam, not a small super bright beam. Since the surface brightness of the '90 is similar to the '50, you won't get any more brightness out of the same lens, just bigger beam.

How about this for an emitter: http://www.luminus.com/products/data..._Datasheet.pdf I think it's 4 SST-90 dice in a single package, wired in series. To get a really good beam you'd want a monster aspheric, but a 50mm might give a reasonable beam. Unfortunately, you have even less surface brightness than the '90, so you won't get more brightness with the same lens, just more area.

But I think I saw a 100mm aspheric somewhere....

[betti154]

I think the SST-90 behind a 28mm lens is not going to give you a very tight beam. I've been playing with an SST-50 and an XML, and some 30mm aspherics. At the same current, the XML gives a noticably tighter, brighter beam, and if defocussed to the size of the SST-50, a much more uniform beam and slightly better brightness. Of course, the '50 can be driven much harder.

Oddly, they both give noticable spill. I'm thinking this is due to light bouncing of the lens mount before going through the lens. I kind of like it. The lens mount is just a hunk of wood I bored a hole in to hold the lens.

The '90 would give you a big bright beam, not a small super bright beam. Since the surface brightness of the '90 is similar to the '50, you won't get any more brightness out of the same lens, just bigger beam.

How about this for an emitter: http://www.luminus.com/products/data..._Datasheet.pdf I think it's 4 SST-90 dice in a single package, wired in series. To get a really good beam you'd want a monster aspheric, but a 50mm might give a reasonable beam. Unfortunately, you have even less surface brightness than the '90, so you won't get more brightness with the same lens, just more area.

But I think I saw a 100mm aspheric somewhere....

Thanks for that. Looks like I'll need to do some playing around. I'm now thinking of a head with 3 * 28-30mm aspherics in it.

I haven't had much time to look at it though as I've been chained to a lathe or soldering iron finishing a few video lights for a cave trip. Get back to this project in a month or so.

[JacobJones]

In theory 1 LED with 1 large lense will throw further than 3 LEDs with 3 smaller lenses. With aspherical lenses bigger is usually better, however quality can have a significant effect on throw aswell. The 66mm lense from deal extreme is apparently very good.

You may find this thread of interest http://www.candlepowerforums.com/vb/...ht-150-000-lux

Person in that thread got over 700 meters of throw using the deal extreme 66mm lense and a Cree XR-E R2

[betti154]

In theory 1 LED with 1 large lense will throw further than 3 LEDs with 3 smaller lenses. With aspherical lenses bigger is usually better, however quality can have a significant effect on throw aswell. The 66mm lense from deal extreme is apparently very good.

You may find this thread of interest http://www.candlepowerforums.com/vb/...ht-150-000-lux

Person in that thread got over 700 meters of throw using the deal extreme 66mm lense and a Cree XR-E R2

thanks, bigger might actually be better! I'll order the DX 66mm and have a play, as the biggest one I've got it 50mm.

[lucca brassi]

I have with SST-90 @ 1m square 160x160 mm and @5m cca 630x630 mm on air through 6 mm frontglass . Lens are aspherics DX 44mm

[DeeperDeeper]

Here's my example
SST-90 with 50 mm lens from DX (sku.12834)
http://yfrog.com/mk3narrow5mj

[betti154]

thanks for the examples.

I've ordered the DX 66mm aspheric and will have a play with the SST-90 and the various lenses.

[JacobJones]

You are all making me want to build another aspherical thrower, im going to order the DX 66mm lens aswell.

[Packhorse]

I really like the size of the 44mm aspheric. Fits nicely in a mag head. 50mm will probably require a custom head and 66mm is getting really big.

In saying that if I can get a tighter beam than a SST-50 with a 44mm and higher lux with a 66mm I may consider it.

[betti154]

Yeah agreed, but I'm thinking function over form on this one.

I was thinking of delrin housing with 10mm acrylic lens to hold the 66mm aspheric, that tapers down to a ~40-50mm heatsink and cable land off that. Won't be what I consider ergonomic but hopefully a good beam. Other option I've got is an old greenforce head for a 200w halogen burner. It is 110mm at the flat lens and tapers to about 80mm, though any effort here would be one off so may as well just machine from scratch.


Regards,
Damien Siviero
http://damiensiviero.com

[lucca brassi]

I have looked on CSM-360 WW ... but price 205,86$ is a little scary http://www.kaidomain.com/ProductDeta...roductId=11124

[JacobJones]

I have looked on CSM-360 WW ... but price 205,86$ is a little scary http://www.kaidomain.com/ProductDeta...roductId=11124

That LED would be awefull for a thrower. It has 4 dues so instead of the beam being a square it would be 4 squares with a dark cross separating the squares. Also the dies don't really have enough surface brightness to make a good thrower

[beekeeper5]

Betti, how is your aspheric light coming along?

[betti154]

Betti, how is your aspheric light coming along?

Progress is rather slow at the moment on my personal stuff. In between moving, resigning from corporate life, and building video lights for all and sundry I've not had a chance to build the SST-90, ahorton optic and 9A driver.

I have built myself a pair of little backup lights, single 18650, ahorton aspheric, single XML @ 3000ma. Powered by a lflex driver, piezo switched with multiple power levels. I'll say that I'm impressed with the optic for backup solutions and when you want massive throw, though I'm still not sure I want such a tight beam as my primary dive light on most cave/wreck stuff.

Next build will be SST-90/Aspheric or 20,000 lumen video light, not sure which. An upcoming dive project requires both so doesn't really matter which I do first.

If you're interested, here's a crappy video that stars the backup light with aspheric. It's clipped off to the anchor chain (in strobe mode) next to my other marker strobe from time index 0:20-0:50.

[Packhorse]

Speaking of crappy videos, here are two where I am using a SST-90 and 28mm Ahorton aspheric.
It was wired up direct drive at the time. So I am unsure how much current it was getting but it was less than 9 amp.
It was my miniMAX project and was focusable although Im pretty sure this video shows it in its "spot" focus.
My buddy was using my quad aspheric maglite.

The wreck is the Rainbow Warrior.

[SmokedCPU]

I have looked on CSM-360 WW ... but price 205,86$ is a little scary http://www.kaidomain.com/ProductDeta...roductId=11124

Last dive in the Fjord i used one of those led mounted on a cpu heatsink in the front of my pimped farallon scooter.
I use the bare led without any reflector. its driven to 4A on 3 die, to use it with a 4 cell battery with an H6cc and a halltoggle

i did not check the video yet, but as other pointed, forget it for a thrower, its about to 4x the size of a P7 so it will be ugly