Multi head XML or single SST

What is the general preference ?

I would imagine the SST emitters have better overall throw when used in a good reflector. The multi reflector XML designs seem to be bright and a bit floody.

Opinions ?

Its pretty relative to the size of the reflector vs the size of the led.

The multi XM-L is a bit more electrically efficient. Single SST emitters seem easier to focus for throw than the XM-L though. If you really want throw though, find an emitter with a brighter surface brightness than either the XM-L or SST emitters. Something with a high surface brightness will often project farther.

The throw depends on the maximum surface brightness of the emitter; the maximum lumen output divided by the surface area of the emitter in square millimeters.

In Dr Jones table below, the XR-E R2 EZ900 has the highest surface brightness at 347 lumens per square millimeter.
Remember that one lumen per square meter, is one lux.
The SST-90 has the 2nd best surface brightness at 300 lm/sq mm.
The XP-C 3rd at 293.
The SST-50 4th at 273 lm/sq mm.
The XP-G 5th at 258 lm/sq mm.
The XM-L 6th at 244 lumens per square millimeter.

Compared to a single emitter, a triple emitter will provide a lot more flood, and almost as good throw.

However, an SST-90 and SST-50, if driven to their maximum recommended amperage of 9 amps and 5 amps respectively, actually have more surface brightness than a single XM-L driven to it's maximum recommended amperage of just 3 amps, therefore the single SST's can throw further than a single XM-L, which in turn can throw further than a triple XM-L.

The XM-L's maximum recommended amperage is 3 amps, and if you drive an SST-90 or SST-50 to only 3 amps, the SST's will have very very poor surface brightness, and totally lack throw compared to a single XM-L or a triple XM-L; here the SST-90 with it's larger 9 sq mm surface area will have even less surface brightness than the SST-50's 5 sq mm surface area.

Thus, a single SST emitter will have slightly more outright throw, but not much flood.
Meanwhile, a triple XM-L will deliver great flood, and good to very very good throw [almost as good a throw as the single SST]; provided the bezel diameters are all the same.


Regardless of which type of emitter is used and how much surface brightness in lux that emitter/s attains, the larger the diameter reflector, the more it will collect and concentrate light into the hotspot, to maximise the brightness/intensity (in lux) of the hotspot, therefore maximising the throw, at the expense of decreasing the lateral surface area of illumination.
A reflector and lens acts like a car's gearbox, increasing one factor, at the expense of decreasing another factor.
The more the larger and deeper reflector increases the brightness in lux [hence the throw], the more the lateral spill surface area of illumination in square meters is diminished.
A larger and deeper reflector cannot create more lumens; the total lumen count remains the same...

I thought XMLs has a brighter surface brightness than SST50 too since all my XML throws farther than an SST-50 in the same reflector. An example would be the Catapult V2 XML vs The SST50 version. I driven the SST-50 to 5A and the XML to 4.2A and the XML still throw farther.....

According to Dr Jones' table, the SST-50 must be driven to 5 amps, to produce a maximum of 1365 emitter lumens, to have a maximum surface brightness of 273 lumens/sq mm.

The Catapult V2 SST-50 only outputs a claimed maximum of 1000 emitter lumens? Roughly 700 lumens OTF.
Below, Selfbuilt tested the Catapult V2 SST-50 to have only 590 lumens OTF, for a paltry 26,500 lux and 326 meters of throw.
Selfbuilt tested the Catapult V2 XM-L to have 760 lumens OTF, 46,000 lux and 429 meters of throw.

Likewise, the old Olight M31 SST-50 [below] also only had 760 lumens OTF, or 800 lumens claimed; which translates to about 1000 or more emitter lumens.
However, the SST-50 can output 1365 emitter lumens according to Dr Jones table.
Maybe 1365 emitter lumens is only achieveable by the latest bin? The J bin?

Something must have gone wrong with the old Catapult SST-50's total lumen output??? Hence the poor throw???
Maybe we must drive the SST-50 harder than 5.0 amps, because some current is required to drive the electronic circuit???
Just like you drive the XM-L to 4.2 amps, and not just to a maximum of 3.0 amps???

I would go single SST. I am avoiding XML LED's because of the nasty green corona they produce.

dheim said:

The only problem, that the SC600 shares with every XM-L light I used, is the greenish tint. The REAL problem is that – perhaps because of the floody nature of the beam – it appears visibly greener than on other lights, most of all on lower output modes…

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