Emitters

Whats the difference with "Batwing" "Lambertian" and "side emitting" emitters?

You might find this informative:
LUMILEDS Data Sheet (PDF)
pages 10 and 11 reference the radiation paterns of the three emitters.

In layman's terms...

Lambertian is brightest in the center of the beam and drops off relatively evenly as you rotate further from the center. Lambertian is commonly referred to as a "high dome" emitter.

Batwing has a high-intensity corona off-center, with fairly steep drops in intensity on either side. It emits light in the center, but the intensity is something like 30-50% of the intensity of the corona. Batwings are referred to as "low dome" emitters.

Side-emitting is the most visually distinct. It has an inverted cone projecting from the lens, and its highest intensity is at close to 90 degrees off beam center. Toss thse into a reflector, and they behave a bit like an incadescent bulb in a reflector.

thanks! I needed that!