Part Three - Lights

The final emitter has the following parameters (right screenshot)

Those settings are almost identical to the first ones (bright spark emitter). Now let's take a look at the light source that's being emitted (below).

And could you guess what this emitter is for? Exactly! Finally, those are the light sources that lighten the local area around the bright sparks. That's why they should behave the way the sparks do (about the same scaling, lifetime and speed). But now those lights are allowed to actually cast some light. And, since we don't want them to add up too much, we need a lot fewer lights [Birth Rate of 150], then we needed sparks [Birth Rate of 1000]. You should avoid using soft shadows though. You will most probably get a memory problem. And, if you think of how it looks in reality, those sparks are way too small to cast soft shadows anyway. Oh, and don't use lens flares on every spark either (well, try it once and see what happens). I added a single light source to simulate that.