Light dispersion on small scales


Skipjacks

Skipjacks

Member
I am starting to put lights throughout my layout. Street lamps, window lights, etc...

They look awesome in the location where the lights are, but the light goes too far. What I mean is that in real life the light from a 60 watt bulb might light up things 20 feet away. But the equivalent brightness of a tiny LED bulb lights up everything a foot away, which is like 160 feet in N scale. So my street lamp is lighting up the train tracks 160 scale feet away.

Other than altering the laws of physics, what can I do to block that light from dispersing too far? How can I have tiny lights on my layout in some areas, but keep other areas dark?

I can't be the first person to run into this. I'm just curious what other people do.
 
First thought is to simply add more resistance to the LEDs, which will dim them. Barring that, you might also try using some white paint. I've used that trick on a few locomotives where the LED was too bright, but I didn't want to modify a board-replacement decoder to add resistors.
 
I don't want to dim them. I want to block the light from traveling outside the area where I want to contain it. Dimming the lights is easy. But then it looks like my scale villiage is having a brown out.

Then I'd have to build a tiny power plant.....which brings out tiny little environmental protesters...and who has the time to deal with all of that? (Okay I'm loosing my mind...time to go to bed)
 
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Have you ever looked at a light from a distance as compared to up close? They're dimmer. The tint of the light is more noticeable and not as white. Your perfectly bright white porch light that illuminates your yard just fine when you're IN the yard, from just a few hundred feet in the air barely puts out a noticeable yellow glow. Lights on a layout shouldn't be all that blindingly bright if you consider that you're in effect looking at it from a distance. Look at your locomotive lights and think about just how blazingly bright those are in real life. You wouldn't even be able to SEE a 60-watt bulb burning right next to that, but of course in scale they're nowhere near that bright, nor should they be. Your LED's are almost certainly also HUGE in scale compared to what a 60-watt bulb would be. You can't have something the scale size of a large TV screen shining like an 800-watt flood and get it to act like it's a 60-watt bulb. If you don't want to dim the LED, then like I said you'll have to paint over part of the lens to restrict the amount of light that's coming out, unless you can possibly find one that has a low enough mcd rating so as to be naturally dimmer. As long as you've got an unobstructed LED burning at full brightness, the light is going to do what light does. Even if you put baffles around it to direct the light, it's still going to be brighter than it should be.
 
Containing light dispersion isn't going to be easy, I think you are going to have make a few compromises to get a reduced lit area. My first thought was adding a higher resistor to dim the light, but you don't to do that for the reasons you mentioned. Only other thing I can think of is coloring the light itself ... perhaps a wash of white over the light and see if that reduced dispersion. I have a feeling though it will also reduce the brightness which will have the same effect as adding a higher resistor.

I think one of the things we have to understand is that not all things can be created to scale, some thing are out of our control, like light. Think your going to be left with one of two choices:

1. a dimmer light source (brown out effect) or
2. working with the light dispersion.

You might want to try using a different type of LED as well, perhaps a warm white or even a yellow and see if that helps at all.
 
Skipjacks said:
IWhat I mean is that in real life the light from a 60 watt bulb might light up things 20 feet away. But the equivalent brightness of a tiny LED bulb lights up everything a foot away, which is like 160 feet in N scale. So my street lamp is lighting up the train tracks 160 scale feet away.
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I think there might be a mistake about the "equivalent brightness". First I believe most street lights use low pressure sodium "bulbs" so a 60-150 watt street light would be much closer to the light output of a 500-1000 watt standard incandescing bulb. But for your 20 foot comparison, a 60 watt incandescing bulb is about 800 lumens. 800/160 = 5. So are your street lamps really producing only 5 lumens of light? That would be IF light scales. Other things in physics don't. This could be a very interesting science fair project for someone. Then even if light scales, I'm not certain your eye seeing that light does. One might need N-scale eyes to see the equivalence. :) I'm trying to think of how things look flying over them at low altitude at night. It does seem like I recall some places the light was in little "pools" around the lamp posts while others one could not even tell where the light on the street was coming from because it was so even.

What type of street lamps are these? The type in a hood that shine down or the kind on the top of a stick that shine all around? Because this might be a volume issue. An average down shinning streetlight has an output "lens" of 8 to 10 inches. An equivalent N-scale would be 1.2mm, is that what you have and do they shine only down or are they larger and bulbous shinning sideways also?
 
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Well it's all kinds of lights. It's interior lights that shine out windows and street lamps. I think I'm just going to have to get creative with barriers that physically block the light.

Though Iron Horseman did hit on something brilliant! You mentioned the hood on street lamps. The street lamps I got don't have hoods, but I can easily put hoods on them. That will do wonders to direct the light downwards instead of out without greatly changing how the lamps look. Perfect!

For the house lights that are bleeding out the windows...I'm just going to creatively position trees.
 
Skipjacks said:
Well it's all kinds of lights. It's interior lights that shine out windows and street lamps. I think I'm just going to have to get creative with barriers that physically block the light.

Though Iron Horseman did hit on something brilliant! You mentioned the hood on street lamps. The street lamps I got don't have hoods, but I can easily put hoods on them. That will do wonders to direct the light downwards instead of out without greatly changing how the lamps look. Perfect!
Click to expand...
In that case you could also paint part of the "bulb" black to make it more focused. That is, instead of having a normal LED who's top is curved, file it flat and paint a frame so that only a 1mm area (or whatever bulb size would be for N-scale) is umm... exposed and letting out the light.
 
I have several tricks, depending on the situation, up my sleeve on this matter.

Loco headlight is nice and bright, but the number boards next to it are too bright; I place 1 or 2 pieces of white or yellow electrical tape over the number boards INSIDE, BINGO bright headlight, not too bright numbers.

Loco light shines downward thru shell gaps: I use heat shrink to limit the light, make a shield around the LED so it goes forward and out and nowhere else. Black tape can also be used sometimes, but heat shrink works best for me in most of my situations.

When the LED is just too bright, and all I want to do is dim it, a tiny bit of white tape over the LED works great. One can also make one or more PIN-HOLES in the tape to make a tiny bright spot. Again here sometimes 2 layers or very rarely 3 layers of white tape.

I have also used BLACK MARKERS to paint parts of a bulb or LED to narrow the angle of the light or shield the light from going where/direction I don't want the light to shine.

For a structure where you want it to appear there are numerous tiny lights throughout, FIBER-OPTICS work great, One LED, several bits of fiber optic can create the appearance of several/many lights in a room/s etc.

I use both bright white and warm white LEDS, depending on my needs/wants. One single bright white LED can be used to provide both bright white and warmer white light by using yellow electrical tape over just the ends where I want the light warmer.

My solutions for my uses are CHEAP & EASY & FAST, easy to change on just a whim! No painting, no mess, no wiring or soldering and removable/changeable without disturbing anything other than tape or marker spots, or heat shrink

JD
 
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