SST-90 / Ahorton 27.2 aspheric still state of the art for MR-11 upgrade?

[ginge]

Hello all.

I have been lurking for a while, reading packhorse's threads and many others - to be honest the more I read the less I seem to know.

I am not really 100% on electronics, I can solder (a bit), I've installed MOSFETs and done big power upgrades in airsoft guns.
I have a small hobby lathe so I am capable of building a new light head.


I bought a used Dive Rite MR-11 that had been converted (at the factory I think) into an LED700/LED LUX.
Here is a picture of the light head:

It isn't blowing me away with power, I guess the option is similar power to a handheld with massive runtime or massive power with reduced runtime and this is in the low power-good runtime camp.


Since I am not a technical diver I don't need more than 1.5 to 2 hours of runtime.


The way I see it I have 2 options:

1: Build my own upgrade.

2: Wait for the Sump Donkey III drop-in upgrade to come out ( I have e-mailed Custom Duo and hope to hear about the projected specs soon).


If I build my own then am I right in saying that for a good, tight beam, good throw and serious brightness then the SST-90 with an Ahorton lens is still the best way to go?

I would be driving it at 9A with one of these.

Battery wise, again, confused.
My used torch came with 2 12v 4500mAh batteries (10 x 1.2 volt cells).

The battery compartment is 59.9mm diameter with 133.5mm of usable depth.
That means if I tessellate the cells I can get 5 22.17mm diameter cells or 7 19.9mm diameter cells into it.

That means that is is possible to squeeze 14 18650 cells into this cannister
Plenty of scope there, I could easily supply 7.4 volt at 15.5 amp hours.


So, do what I said above, driver, LED and lens or is there something better out there.

I know Packhorse was trying to find a good aspheric lens in the 35mm range but I can't find one, is there one out there?

SST-90 still the best for this application?

Driver good enough, anything better available?



Anyway, sorry for the extremely wordy first post and thank you for your time.

 

[DIWdiver]

I think the SST-90 may be a bit big for the Ahorton lens. I think Packhorse was using a 44mm with the SST-90.

Member jspeybro is offering 25, 38, and 50mm aspheric Fresnel lenses. I'm not aware anyone's done any comparisons against Ahorton's. I saw one beamshot of the 50mm lens, which looks like the beam is 30 cm wide at 3 meters. That's about the same as the Ahorton. We're talking XM-L emitter in both cases, SST-90 would be larger.

If you can only fit one optic in the head, the SST-90 is the most lumens you can get. But an XM-L will give you tighter beam because the die is smaller. I'm not an optics guy, but if I recall from other threads, you will actually get a brighter beam from the XM-L because the surface emissivity (lumens per mm^2 of the die) is higher. Half the lumens packed into less than half the area. I'm sure someone will correct me if that's wrong. (also 3 times the battery life!)

But if you could get 3 XM-Ls in there, it would blow the pants off the SST-90.