Fiber Optics
Here's what I've tired with FO.
I've drilled a small hole in an old structure, inserted the fiber and then burned the end -- to expand the viewing angle and help hold it in place.
That looks like a bare bulb hanging on a wall in a small fixture, but the problem is that if you're just slightly past the viewing angle, the "bulb" disappears. Also, there is no "spread" of light from that light source, so the wall or let's say loading dock doesn't have a cast of light from this source. It's generally just a pinpoint of light. Which might be fine in an overall scene that has other lighting going on....not sure. I was just hoping to get more realistic lighting with FO.
FO works great for things like marques, headlights, etc. The only thing that is problematic is that the FO needs to come straight into the object or have a relatively broad bend. If you bend the FO too much, you'll get a large light leak at the bend.
The other thing I've tried with FO is to "trim" around the clear outer casing of the FO by the tip. So that technically the light is viewable from all sides. But side-leaking light is much dimmer than end light, so I didn't think this worked very well. But that method would work well for a small flame if you cut the FO into a point. Like the flame in a gas street lamp. But again, you run into the problem of the FO not casting the light onto nearby objects.
Another possibility I've been paying with is to set up "theatrical" style lighting within the layout. I haven't seen this done before, but thought this might work.
The idea is to use the FO to place the "points" of light on stuctures and around the layout. Then use small spotlights, hidden by other structures, ceiling valance or scenery to cast the light onto the structure wall, centered over that FO point. The combination of the two, should, in theory, provide the FO "bulb" or light origin, and the cast it's giving off. I think the spotlights would need to be relatively dim and would need some thought behind placement. Add in structure interior lighting and some logically placed grain of rice bulbs and the overall effect should work.
I played around with this last night with a small LED that I made a "shade" for -- to cast the light into a specific direction. It seems to work pretty well. I would just need to be careful about making sure a train would never pass in front of a spotlight and that the spotlights not cast light on anything in between itself and the obect it's lighting.
Might be difficult to pull off, but I think I'm going to experiment with it.
I'd still like to do more with the FO rather than jump to out-of-scale grain bulbs, so if anyone else has any suggestions....