Smoke Vapor needs backlight?

If you could squeeze a very tiny LED somewhere between the stack and the generator it would probably look good for "Night Runs", but that's an awfully tight space. You can only try it and see.

One technique is to have a search light car behind the locomotive, with the light shining towards the smokestack. Another technique is to have the right of way cross a beam of sunlight through a window.

 

Later post war American Flyer locomotives has a clear/red plastic smokestack illuminated by the headlight.

Smoke will pick up light like a projectors screen.

 Considering your running in daylight near a window, your likely just getting less light from the non-window side of the layout where I assume you view it from. So you are looking at the dark side of a cloud.

You are also battling light coming through the cloud from the other side. Penetrating light will make it less visible.

 A bright lamp aimed from the dark side of the room somewhere, should make it easier to see.

 The issue you will have with putting it on the engine is unless the bulb/led protrudes past the surface, you are unlikely to get a wide enough beam to be effective.

 The result of a recess will be a "cylinder" of light, as the hole is now an iris.

The smoke will likely accent the rear of a light cylinder, with sharp edges of bright light, then nothing, or little outside the beam. 

 Take a look at the video "grab" of my rocket running in the dark.

The lit led makes it look like a narrow burst of smoke, but in fact the smoke plume is wide and dense. Its lite actually makes it look less dense due to penetration.

 

You want your light to reflect off the cloud, not penetrate from within.

Not unless you have a rocket on rails too

 

 

 

 

Yes, you're so right. I just checked the area where I get the most dramatic smoke visual and the background is black...up to about 8 inches above the engine. Then the sunlight streams in over that black background and I guess reflects off the layout items in front of the smoke and is reflected off the smoke vapor. So if I made a smoke friendly background all around the layout, black, and some lighting directed toward the outside with the engine in the middle, that might be the best situation.

Thanks for the replies...still thinking about how a light on the engine would be directed to illuminate the smoke vapor.

I observed the same principle a while back and took advantage of it when I recorded this video of my LionChief Plus Hudson puffing smoke

 

https://www.youtube.com/watch?v=Qjvec4CdbyY

It would need a slot shaped lens with a focus to put a Mohawk of light above the train length. Or more than one.

 

I don't know what modern bulb would work best, unless they still have small R series spot bulbs. They used to be in every store.

But a small spot in a point-able, normal but suitable bedroom, or desk lamp, etc., would work nice...... or.....No room? Get a recessed or low rise led spot(that's right they have new ones, duh) and mount it in the ceiling corner opposite the window....or better, the wall directly across at plume height.

 I'm out of practice but I did theater lighting. My first written paycheck at 15 was for running a 440v 6ft long carbon arc spotlight. 110+ degrees on stage if I focus you right.    

Could you have a building that stands high enough by the track with led bulbs shining down from a roof overhang lighting the building and the engine as it goes by to light up the smoke? Might be a cool way to get the lighted smoke effect. A couple bulbs angled to light the building front and sidewalk and a couple bulbs slightly angled out that catches the locomotive smoke as it passes by.