An even cloverleaf is a good indication it’s well-centered. Any “irregularity”, eg, 2 short and 2 long, only 3 lobes, etc., generally means it’s a bit off-center.
The smaller the chip, the more critical it is to center it, and the harder it is, too.
It is pretty even with 3 leafed clover, so guess it is well centred. I tested it yesterday and am pretty impressed for this small form factor to be. Will keep it as is. Also considering to buy L21A or the upcoming SBT 90.2.
It’s a 3V LED so it will work, though it won’t drive the LED to it’s max potential. I’m using Simon’s 8A buck driver.
The Osram’s have very small emitting areas so have more throw than other LEDs. The CULPM1.TG is a 4040 package so can be driven to higher currents than the 3030 variants.
Unfortunately I don’t have a spectrometer to measure CRI. It’s ~4900K at the lowest current setting and ~5250K at 8A. I’m getting ~1600 lumens OTF with the M21C host. I got decent focus just dropping it right in with one of the 4040 centering rings. I did have to put a shim under the bezel as the reflector moved around slightly if I shook the light too hard due to the thinner centering ring.
Can’t get any beamshots tonight; it’s pouring rain outside.
If you see a dark hole in the center of the beam only when it’s close to a wall, that’s actually a sign of a well-focused emitter. Totally normal for a thrower.
Everything that hits the reflector gets tossed forward in parallel rays. Anything that comes out the front of the LED ends up as spill. The “hole” in the reflector where the LED sits, and inner part of the reflector where no light from the LED hits (coverage is never 180° but maybe 160° at best) is also part of that hole.
Imagine the hole being really big, and you don’t have a cup for a reflector, but a curved ring. That’s what’s projected at least until the hotspot diverges enough to fill it in.
Pretty much all my good throwers have at least a slightly darker spot in the middle.