My quad XR-E aspheric running at 1400ma and a tight focus is pretty competitive against a 21w HID salvo. But the beam is quite different.
A SST-90 with the right reflector or aspheric will be just as bright or brighter but once again a different beam.
4 XP-G's would also be pretty close but ....... yep different beam.
So really as with any other light design you need to first decide what sort of beam you are after then choose your LED and optics to suit. So many do it all arse about face and choose a LED because it puts out the most lumen then find an optic that will fit and end up with a beam that they had no idea of when they first started.
I agree with your last point.
Can you briefly describe the beams in those example above?
I'm guessing the 4 XR-E's with aspherics is the most tightly focused with 4 XP-G's with the proper reflector/TIR coming next and the SST-90 being more of a flood/video light no matter what reflector or optic you choose.
Have I got it about right? My frame of reference is nighttime diving or daytime diving where the light is on and is needed for the entire dive so only a little brighter than nighttime diving with average viz of 15 feet.
I like a beam tight enough to deal with that viz and to be useful for signaling but I"m not too concerned about DIR 4 degree beam type of signaling .
So, I would think that 3 XP-G's driven at 1.5 amp might work as would 4 XR-E's. The XR-E's could take aspherics but the XP-G's wouldn't.
Could you still have an 8 degree beam using a reflector/TIR with 3 XP-G's?
I can picture these things in a single emitter light but I'm unclear as to what effect using 3 or 4 emitters has. I see reflectors set up for 3 or 4 emitters and the individual reflectors are tiny. I'm not sure what the cumulative effect is. I never see this aspect of beams/optics/reflectors discussed much.
As an aside, I just got a XP-G non-diving flashlight. My others have been XR-E. So for moving around the yard at night to me the XP-G is only an improvement. It still throws far enough in that environment and there is more hotspot and therefore less spill. It's more like I would expect a flashlight to be.
Walking around with a XR-E seems silly at times (regarding the beam angle) as I'm trying to light my way with a decent sized spill but then there's this very bright and small hotspot that does nothing for me other than to constrict the iris in my eyes.
I can imagine how a SST-90 probably wouldn't have the kind of beam for diving that I would need but I'm seriously wondering why a XP-G might not be better than XR-E. It's the 3 emitter issues that I'm not clear on.
