I have been using 3mm yellow led's in the past. All windows show the same light. Nowadays I would try to make sections in the building and install smd led's, for each section/room. Search for soldering smd led on youtube.
Here is a source for small SMD LEDs. http://www.ngineering.com/ He has How-To's also. Lots of cool tiny lighting effects. Although a bit expensive, if you already possess all you need to know about soldering SMD's and have the equipment, you can find large amounts of SMD LEDs on ebay for cheap. Or you can register here and purchase what you want. http://www.kingbrightusa.com They have a large selection and lots of varying colors, dual and triple color LEDs. Once you register with them you can see the pricing which for some is fairly cheap in bulk!!! Lots of tech info on the LEDs. Your call!!!! Have Fun Hobo Tim
These are excellent ideas Originally I was thinking of using grain of wheat light bulbs and soldering them together in series, but if one blew out, you'd have to unsolder it and put another one in. I suspect they get rather warm in confinced spaces as well. Then I thought about the white mini led Christmas lights but I wonder if the wiring would be too stiff and thick to stick up through holes in the base and into the small openings in buildings. I also was considering the lights and sockets that Marklin makes but they appear rather bulky and I don't like the look of them. I'll have to check out these websites. Thanks guys.
Another way to light structures is to use fiber optics and keep all the lighting (and any heat) under the layout. If you use heat (like an open flame) to melt the end of the fiber, it looks and acts like a minature light bulb. You can use almost anything on the other end: grain of wheat, LEDs, even flashlight bulbs. I like using LEDs: particularly the T-2 type you've been using. Depending on the size of the fiber you're using, you can drill a shallow hole (about a #70 bit) in the LED lens and glue the fiber in it. Hope this helps, Mark
Lightbulbs of any sort are a thing of the past. LEDs are cheap (literally pennies a piece on the Bay), reliable, and no more difficult to install than bulbs. You can even get them pre-wired with resistors and pigtails, making them a snap to wire. Just remember to either paint LEDs with white paint, or sand their entire shell with fine sandpaper to better diffuse the light--LEDs are directional in nature, sending nearly all of their light in one direction.
The LED'S sound like the best option for sure but the fibre optics thing is a good idea too. The thing I like about fibre optics is that they are long filaments and in some cases they would have to go through up to 8 inches of foam base in order to get to the bottom of the structure to light. The smallest long shank drill I have is 1/8". Fibre optics need a light source and I can get any number of stick up battery powered lights for this purpose. These structures don't need really bright illumination, just enough to make them stand out. But I do need to add 2 plain goose neck lamp posts. One in a barn yard and another in a parking lot. I know where I can get them and they do have grain of rice bulbs in them. Something to think about.
I have never found fiber optics to be adequate for much of anything except marker lights on tractor trailers and other similar special effects. Lighting structures requires a fairly thick bundle to deliver sufficient light, even at a modest illumination level, with a comparatively intense light source driving it. And then you have the issue of diffusing the light once inside a structure, as fiber optics deliver far more directional light than LEDs. In my mind, I see no advantage to threading fibers through a foot of foam than a pair of wires for an LED.
I used all LED strip lights (except a few incandescent street lights). The heat is minimum, the lighting is bright, have no problems with blow-outs. For the drill bit, I eventually discovered that a small diameter stiff rod or actually a coat hanger can be shoved through several inches of Styrofoam very easily. Punch hole through then tape wires to rod and fish through to bottom of layout.
Now there's an idea I hadn't thought of. Very interesting. I'll have to investigate this further. Thanks