Movers
Lightning_Hunter writes: Most people know this, but you can sometimes light a mover better if you set the WorldRayTraceKey to the proper keyframe. If you set it to 1 for example, it would make light the mover according to it's location in keyframe 1 rather than 0 (which is the default).
Hellscrag adds: Actually, that's the BrushRaytraceKey Lightning_Hunter refers to. WorldRaytraceKey effects the way the world around the mover is lit. Sometimes you don't want your mover to cast a shadow in either keyframe. If you give it an additional keyframe that isn't part of the movement sequence, you can move the brush up into the sky where it will not obstruct the raytracing of any surrounding lights. You can do this with regular geometry as well - simply add it as a mover that doesn't go anywhere. This is why the cross on the roof of the church in Na Pali Haven appears as a mover - so that it casts no shadow on the roof around it.
Frieza adds: Apart from the option BrushRayTraceKey you can also set bDynamicLightMover to true in properties/movement of the mover. This way the light will be calculated as the mover is moving. However, this does slow a map down so use it wisely.
Coronas
Lightning_Hunter asks: Is it possible to have a lens flare that can be toggled on and off? I tried using a triggerlight but it just seems to stay on all the time.
Hellscrag replies: You have to use an AttachMover behind the scenes to drag the light actor with the lens flare out of the visible area. Funny you should mention it, as I just did it for the first time in the new Triskaden map for Deja Vu...
Naveed asks: How do I add coronas to laterns and have it look nice?
Hellscrag replies: Put a light source in the middle of the lantern mesh with 0 brightness but a decent radius, set it to bCorona=true under "light", then choose a lens flare from the GenFX package (I'd suggest "3"), and set it as the light source's skin under "Display". Rebuild geometry to show the flare, remembering to set the light's drawscale to something low like 0.2.