These charts are a good example of why BRS bugs me. The fact that their charts are official looking leads people to overestimate the importance of them, and what can be determined from them.
In both of these charts, it is very clear that the 24x24 testing box is too small to adequately describe the lights, and completely ignores that almost nobody should be running a single LED pendant (more, smaller pendants is almost always better). The G6 is designed to pitch light much wider - so you
should see much less dropoff as you get further off axis - but we can't see any of that.
And there's no way in these single charts to determine the interplay/overlap between multiple lights - which is super important. You put a 2nd G5 24" away from the one in the chart, and that 557,590 on the left border is going to get higher, and the hotspot isn't going to be directly below a light - it's going to be between the two lights.
And that isn't even dealing with the fact that the thesis all these charts started with - that if you can get even par across the top you'll have the same "lighting quality" as T5 - is just nonsense. Light is
directional. It's a particle/wave. A big part of the reason T5 works well is that it's emitting light from every part of the tube, and every nook and cranny on the coral gets light.
So you can't just say "Oh, I've got 350 here - great for acros" because if you're not in the center of the tank, the coral is only being lit from one side. So people build out these tanks focusing on BRS par numbers and then end up with their Acros all growing/leaning towards the middle of the tank and only colored up on one side (the side facing the light, not necessarily the side facing the viewer). And then they kill everything trying to fix the problem of their corals being brown with flow/alkalinity/nutrients/etc and never even question that the entire problem is the chart above being
sophisticated nonsense because "par is fine"
.
Par charts like this are useful for comparing lights with very similar lens designs - but the more the structure of the lights change, the less useful they are, because they're measuring very different things, and because the wider the spread of the light gets, the more additive overlap we get between fixtures. 350 PAR on t5s or panel LEDs that cover the whole top of the tank means something very different than 350 par below a single high slung Kessil.
The chart above just tells us that the G6 is less focused than the G5 - but that's
literally the point of the design of the G6. And this lower focus is a bad thing for small tanks running single lights, but a great thing for big tanks where you are going to have multiple lights, and they're going to overlap, and corals are going to be lit from more sides. (again, multiple small lights are almost always better than one big light).
