Layout Lighting Fixtures


There are a number of ways to light a layout, including room lights and lights built into or directed at the layout itself. Choosing which to use will depend on evaluating their plusses and minuses against your specific needs. Does cost dominate, or are you willing to pay significantly more for marginal gain? How do you operate trains, and what needs does that impose in terms of the level of light needed? See the Qualities of Light page for more on that topic and about light as it applies to layouts in general. And finally, what are you trying to do with the light: evenly illuminate the whole layout, or highlight individual scenes?


Room Lighting


Even if you have specialized layout lighting, you’re going to need to also have some amount of room lighting. People need to see what they’re doing in the aisles between the layout sections, and you’ll need some level of light for general work in the layout room when not operating the layout. If you use room lighting to also light the layout, you’ll probably need more light fixtures (and thus spend more on room lighting), but you are unlikely to be able to completely eliminate room lighting if you add specific layout lighting.

If you did use room lighting alone, one problem would be that it’s going to be behind the people looking at the layout, and thus they’ll be casting shadows on exactly the place they want to see. This is probably the most serious issue with use of room light, although the overall dimmer level of illumination can be problematic as well.

One thing that’s important to consider here: if you’re going to use room lighting at the same time as you operate the layout, you should use the same “color” of light for both. The room lighting will provide a form of “fill” lighting for shadowed portions of the layout, due to light from distant fixtures or walls, and if that makes models in the shadow look particularly different in color, it might be a bit odd.

One possible exception to that: if you use “spot” lighting on the layout with individual spots illuminating scenes, and no adjacent spots filling in, you might want to consider using a cooler color for the room than for the spot, to mimic the difference between sunlight and reflected sky light. In practice this would be very hard to get right, as shadows from one spot are going to be too sharp compared to normal sunlight.

But if you’re going for even lighting, use the same color (and good CRI ratings, above 80) for both.

Typical room lighting is going to produce light levels around 100 to 175 lux, unless you use more fixtures than usual. This is a good level for moving around and seeing controls. It’s a bit dim, however, for reading normal-sized print, and that gets even worse as you get older. And it’s not really sufficient for fine detail work, like manually uncoupling cars using a “pick” or similar tool.


Can Lighting


Light fixtures for bulbs can be recessed into a suspended ceiling. One method is the circular “can’ fixture, which points directly down, but has the fixture above the ceiling, placed between the joists holding up the floor above. These are good for illuminating aisles, but since most of the light is going on the floor they’re really more suited for “room” lighting than illuminating the layout itself. You could put them above the layout itself, but placement would need to be carefully considered as these fixtures create bright spots, and you’d usually want those to be either large or overlapping with adjacent fixtures. The relatively large fixtures used for these throw a broader, more diffuse spot than smaller fixtures, but also tend to have bulbs with a lower overall light output. 350 lumens is typical. The larger spot, greater distance to the fixture, and lower output combine to make the light level at the layout surface from these dimmer than other solutions.

Bulbs for these can be ordinary bulbs, but more commonly have built-in reflectors of R30 or PAR30 design (PAR is brighter, but may cost more). These also come in “flood” and “spot” styles. Both produce a localized circle of light, but “flood” bulbs produce a wider, more diffuse, circle and are preferable for room lighting (spots are for illuminating specific objects).

A typical light bulb for these is a 60W halogen PAR30 3000K flood with a silvered reflector, producing 1090 lumens These can be had for under US$5 in quantity. LED bulbs are also available, but tend to be dimmer. A 15 Watt LED bulb producing 790 lumens is typical, but costs about US$30 (or more) as of 2014 and may have poor CRI ratings (often none are listed, which is a very bad sign). The ones I have seen mostly range from CRI 79 to 87, but some are up to 92. Because these are designed for room lighting, bulbs with speciality colors are rare, but I have seen some LED bulbs with colors from 4100K to 6500K.

However, unless supplemented with some other kind of room lighting, or through use of a large number of fixtures, the relatively low output of these (compared to fluorescent tubes) is likely to result in rather dim room lighting. That may not be a problem, if these are coupled with other kinds of lighting.

There are also specialty recessed fixtures, similar to cans, which can be aimed slightly to one side. These add some flexibility, but typically require special-purpose “spot” light bubs not suitable to a layout, and come at a high cost. I’m omitting them from this list, since I don’t consider them suitable in general for layout lighting, but they could provide specialized “scene” lighting.

Benefits:
- Effectively zero space required.
- Low cost fixture (under US$10).
- Takes low-cost bulbs (under US$5).
- High CRI LED available (at a cost).

Problems:
- Creates bright “spots” below the fixture.
- Spots are not easily directed at place of interest.
- Low lumens and distance make for dimmer light.


Ceiling Fluorescents


Another option with suspended ceilings is the fluorescent tube fixture, often found in offices. These allow use of long fluorescent tubes, which tend to be both brighter and more efficient than CFLs. These are typically in two-tube and three-tube fixtures for use with suspended ceilings, but smaller one and two-tube fixtures are available for mounting on solid ceilings. The most familiar type of fluorescent tube is the T12, but these are being phased out in favor of the smaller and more efficient T8, and any new construction should probably use those. A more compact, T5, size is also available, but in shorter bulbs and at a higher cost. These are more applicable to constrained-space applications (see Fluorescent Valence Lighting below for more on that).

These fixtures can’t normally be fit between joists in a residence, so they’ll require the ceiling to be set lower than it might be with other methods, although only by about 3-6 inches (7.5 - 15 cm). However, two-tube fixtures could potentially be placed between joists, but long two-tube recessed fixtures are hard to find. Tubes are available (in the U.S.) in 2’, 4’ and 8’ sizes, and there are also fixtures that take U-shaped tubes, however those are harder to find high-CRI bulbs in multiple colors for.

These can be had for all the usual fluorescent tube types (in particular the newer T5 and T8 types) and in a wide range of CRI ratings and colors. However, most typical bulbs will be in the CRI 85 range at a reasonable price, with the cost of incandescent-equivalent CRI 95+ bulbs both very high, and typically limited to higher temperatures. A typical two-bulb 2’ x 4’ fixture would use 2-4 T8 bulbs at 32W and 2800 lumens each.

In researching fluorescent tube fixtures, my original thought was that T5 bulbs were the preferable type. These are more efficient, and brighter, than T8 bulbs (and the older T12 type is being phased out). And it seems to be easier to find high-CRI versions. However, T8 fixtures have the same range of bulbs (it just may be harder to find them) and are generally less expensive.

There is also a “high output” series of T5 that produce about 1.7x as much light as the standard T5 (5,000 lumens vs. 2,900) for about twice the power (54 W per 4’ tube) so you could have even more light. However, the only fixtures I’ve found for these use a commercial-rated ballast that produces more electromagnetic noise (EMI) than is allowed in a residential installation. These could be suitable for a club layout, but probably not for a basement one since they might interfere with TVs or radios in the house (or in the neighbor’s house).

Normal fluorescent fixtures do not allow the use of dimmer switches. This is annoying, as it would allow very bright light for use during photography and layout construction work, and dimmer lighting during operating sessions (and even dimmer light to simulate a “twilight” environment, where lit buildings on the layout will be more obvious). It’s possible to get dimmable ones, but this requires a special ballast, and a quick search suggested that the ballast alone costs about US$150 (they can be bought cheaper in quantity), and you would need one per fixture. That’s impractical. However, see the discussion in Fluorescent Valence Lighting below.

If you assume that these fixtures are spaced along aisles with gaps of four feet lengthwise between fixtures (and effectively none to the side due to walls and backdrops), then illumination at the layout surface is likely to be around 750 lux from a two-tube fixture. I suspect reality will be somewhat less than that, due to loss in diffusers or against walls, but it’s still going to be quite bright for room lighting.

There are also LED-based fixtures. These come in several colors (3000K, 3500K, and 4000K) and with relatively high output (4,000 lumens from 45 Watts), but the ones I’ve seen so far don’t specify a CRI, which means they’re probably below CRI 80. From what I’ve read, LED floods tend to have a narrower beam than halogen or CFL floods, which may require the fixtures to be closer together. They also do a better job putting lumens out the front of the light, which means that even if they are rated lower than a CFL, they may be brighter in use.

Fluorescent lights have driving circuitry called a “ballast”. Newer ones use an “electronic” ballast, which reduces the noise typically associated with fluorescent lights, and operate at high frequency (above 20 kHz) to effectively eliminate the “flicker” associated with non-electronic ballasts, which operated at line frequency (50 or 60 Hz).

Note the fluorescent tubes produce a small about of Infra-Red (IR) radiation, and this is pulsed (because the electrical supply of the tubes is pulsed). Depending on the ballast, this may be at a frequency that could interfere with reception from IR hand-held throttles.

Benefits:
- Low cost bulbs (CRI 85 4’ T8 tubes under US$2 in quantity).
- Bright: a two-tube 48” fixture puts out about 5600 lumens.
- Variety of colors (3000K, 3500K, 4000K, 5000K, 6000K)

Problems:
- Distance from the layout makes these less bright.
- Lack of placement flexibility may lead to shadows.
- Hard to get better than CRI 85, and cost if you do is very high.
- Fixture cost is moderately high at US$75+.
- Use tubes containing mercury (dispose as hazardous material).


Track Lighting


Another option is track lighting, which uses a track fixed below the ceiling, and fixtures that clip to the track and which can be aimed. This is problematic with the low ceilings often found in basements, but does allow greater flexibility. Lights from the same track can be pointed down to illuminate aisles, or pointed to either side to illuminate layouts from the front.

The spots of these are usually more focused, but this can be overcome with more fixtures, and does tend to put more light on the layout itself. The downsides are cost (more fixtures and more bulbs, with a relatively high cost due to their specialized nature), and an irregularity to the lighting. I used these on two different layouts over a twenty-year period, but ultimately became dissatisfied with them. I did however experiment rather extensively with how to best use them, particularly with my Sumida Crossing layout.

In the case of my layout, difficulties of the room ended up with the lights placed at a variety of distances and angles (some parts of the room just couldn’t have track lighting due to hanging pipes and ductwork in the way). But I did have one stretch that was close to what I thought of as ideal. The track was in front of the layout, but close, with a distance from bulb-face to the center of the layout directly in front of it of 37” (94 cm). I ended up placing the lights on 16” (41 cm) centers. With three CFL bulbs along this section, the light was measured at 220 lux directly in front of the bulb in the layout center, and 200 lux 8” to one side, halfway between the bulbs at the layout center, a 10% variation even with close spacing. Working backwards, that suggests that the area being illuminated was about 0.5 m^2 (210 / 420), or a spot diameter of 0.8 m (31”), which roughly matches how I’d positioned my lights, so that makes sense (I’d positioned them to avoid obvious bright spots).

There’s still a 10% variation in light level between spots, and while that really not obvious to the eye, it does sometimes show up in photographs. It also means that the theoretical 24’ layout described above would need 18 fixtures. With halogens that would be 810 watts. Oddly, that works out to 33 Watts per foot, and so is on a par with the 25 Watts per foot for 176 lux from the lightbulb example. I’d have expected the focused fixtures to do better, but they really don’t seem to. With 14W CFLs we’re down to 252 Watts, or 10.5 Watts per foot, so we’re getting some benefit from the use of fluorescent bulbs.

Most CFLs do not have a CRI rating, but it is possible to find some in the low 80s, and a few daylight versions rated 90. For color, the terms Soft White (2700K) and Bright White (3500K) seem to be most common. Daylight may mean either 6000K or 5000K. I was unable to find a CFL rated around 4000K.

CFLs, being fluorescent lights, have a “ballast” (driving circuit), but this is built into the bulb. CFL ballasts are always of the electronic kind that reduce noise and flicker.

Benefits:
- Flexible positioning and aiming of lights.
- Relatively inexpensive fixtures (US$18) sharing power supplies.
- Use of moderately-priced (US$6) bulbs with good CRI.
- Range of colors available.

Problems:
- Clearance issues with low ceilings.
- Low, but focused, light output.
- Uneven lighting.


LED Panels


One of the newest forms of light is the LED panel (sold under a variety of brand names). These are thin panels that have an evenly-illuminated surface. They can be as thin as 0.55”, or 14 mm, though others are the same thickness as fluorescent tube fixtures. They come in the usual 2’x2’ and 2’x4’ sizes, as well as others (e.g., 1’x4’). They do put out a very high light level (about 1000 lumens per square foot), but actually require a bit more electricity than an equivalent fluorescent.

Depending on the manufacturer there may be more colors of light, or higher CRIs (I saw one rated at “>80” for 2700K and 4000K and another at a CRI of 83 for 5000K and CRI 90 for 4100K.

However the cost is very high, more than twice the cost of an equivalent T8 tube fixture with bulbs at a minimum, and four times the cost for higher CRI models.

At present, these seem to be more an indication of what we might have in the future, than something usable today. We’d need higher CRI, lower cost, and some more flexibility of shape (a 6”x4’ fixture suitable for valence use, for example).

Benefits:
- High light output.
- Power efficient.
- Standard form-factors for suspended ceiling use.
- Good range of colors, but limited by manufacturer.
- Potential for use as valence fixtures.

Problems:
- High to very high cost.
- Marginal to okay CRI.
- Limited range of high-CRI colors.


Valence Lighting


A valence is a structure above the layout itself, consisting of an upper support and a front screen, similar to a layout fascia, that hides the support from view. The inside of the valence structure will typically be painted a light color to maximize the light redirected to the layout. Lights are mounted behind the screen, close to the front, and the front needs to project slightly beyond the layout edge so that models are not back-lit. It is most common to use fluorescent tubes with a fascia, although other fixtures could be used. Space is typically limited, and even more so if a multi-deck layout is being created, so the low profile of fluorescent tubes is a big plus.

Modelers have also used light bulb fixtures behind the valence, although with incandescent bulbs this produces a lot of heat. Use of Compact Fluorescent Light (CFL) bulbs makes this more practical, and such bulbs are claimed to produce a more diffuse light than normal bulbs (I’ve only used CFLs in track lighting, so I can speak to this kind of use from experience).

Other technologies, like EL panels, do not produce the brightness or color quality (high CRI) needed for layout lighting. However there are LED-based panel lights which may in the future reach a reasonable cost and color-quality level for such use. LED bulbs may also be an option as prices continue to decline.


Fluorescent Tube Valence Lighting


The single-tube fixture is typical. To avoid/minimize dim spots, these must be placed end-to-end. Use of longer fixtures (e.g., 4 or 8 feet) is preferable to minimize the places where fixtures meet. T8 fixtures will cost less overall, but T5 are more compact and this may be desirable, particularly in multi-deck layouts where space is at a premium. T5 bulbs are only available in shorter sizes (35 inch bulb length is the maximum).

Tubes provide about 700 lumens/foot (2300 lm/m) in T8 size, but since the valence is located close to the layout, this provides very bright lighting (potentially around 800 lux, although loss in reflection and to the aisle probably reduces this some). A plastic diffuser can be used to “soften” the light (make shadows less abrupt) and will also eliminate any risk of UV light escaping from the tube and dim the light some. Diffusers will add about $1/foot to the cost. T5 bulbs are even brighter, at about 1,200 lm/ft (3,900 lm/m). Older T12 bulbs are being phased out, but were about 900 lm/m.

Note: Normal fluorescent fixtures are not dimmable. Using a dimmer switch reduces voltage to the bulb. While this may allow for some dimming depending on the specific fixture (ballast) in use, it is likely to shorten the life of the bulb. Specialty dimmable fixtures are available, but at a substantial cost and with some limitations on their use (see below).

For space, a typical one-bulb fixture can be mounted sideways to minimize height, but this will require the valence to protrude further beyond the layout edge. Typical space requirements (valence height excluding supports) are 4 inches (10 cm) for a vertical T8, 3 inches (7.5 cm) for a horizontal T8, 1.5 inches (~4 cm) for a vertical T5, and (don’t have specs) for a horizontal T5.

T5 bulbs are somewhat more expensive than T8 (in 4’ length, US$5 - US$10, versus less than US$2).

It might also be possible to create your own fixture by purchasing the sockets and ballast separately (with an electronic ballast, a separate “starter” is not required). Modern “electronic” ballasts that support two 4’ tubes cost around US$20 in the standard form (less if bought in quantity). Sockets are “medium bi-pin” for T8 and “miniature bi-pin” for T5 and cost only a few dollars. However, this could be extremely risky in terms of the potential for electric shock. The output of a ballast is very high voltage AC, which is why wiring between ballast and bulb is usually contained within a grounded metal fixture. Modern electronic ballasts also contain capacitors, and may retain a charge even after being unplugged.

It is probably better to use a commercial fixture, despite the added size. If dimming is required, specialty ballasts providing for dimmer control cost around US$60 purchased in quantity and can replace the ballast in the fixture. If you don’t plan to replace the ballast, be sure to purchase one with an electronic ballast, to minimize noise and avoid flickering lighting.

Even dimmable fluorescents have issues. Specialty bulbs may be required, and all bulbs on a dimmable ballast must be the same kind (brand, wattage) and be replaced at the same time (real current draw varies with age, and they need to be close to identical). And all ballasts controlled from the same switch must be the same model. An initial “burn in” period of around 10 hours may be required before all lights will work reliably and at similar intensities. (source is this PDF, apparently based on a 2001 discussion on sci.engr.lighting I haven’t been able to find).

Benefits:
- Very bright light. Possibly too bright.
- Even lighting.
- Low-cost fixtures (2’ T5 or T8 costs about US$25).
- Low cost bulbs (CRI 85 4’ T8 tubes under US$2 in quantity).
- Small to very small size for constrained space use.

Problems:
- Hard to get better than CRI 85, and cost if you do is very high.
- Not dimmable (except at high cost).
- Use tubes containing mercury (dispose as hazardous material).


Bulb-based Valence Lighting


Although lights behind a valence are relatively close to a layout, and need to be somewhat continuous to provide good, even, lighting, some modelers use standard bulb fixtures spaced along the valence. This works best if the valence is relatively distant from the layout (i.e., not at the close spacing required on a multi-deck layout) and the bulbs are fairly frequent. CFLs are also said to provide a more diffuse light than incandescent bulbs, which works better in this application, although at a higher cost per bulb, at least at present.

If CFLs are used, it is important to choose ones with a specific color-temperature (e.g., Cool White or a numeric temperature, see the Qualities of Light page) and a CRI rating of at least 80, 85 would be preferable.

Light output depends very much on the bulb chosen. A 100 Watt incandescent bulb produces 1,600 lumens, but most CFLs are smaller, and many produce less than 500 lumens. CRI 82 100W-equivalent CFLs that produce around 1600 lumens are fairly common, but costs can range up to US$6 per bulb, although lower costs may be found for some, particularly if purchased in quantity. It is also possible to find CRI 82 bulbs producing up to 2100 lumens (for US$10 per bulb), but these are uncommon.

Note: it is also possible to get specialty CFL fixtures, rather than the standard screw-in kind. These cost more, and may not allow for future upgrading to LEDs, so they’re not covered here, but do support use of bulbs longer than the standard kind, and so may provide for more even lighting.

Most CFLs do not have a CRI rating, but it is possible to find some in the low 80s, and a few daylight versions rated 90. For color, the terms Soft White (2700K) and Bright White (3500K) seem to be most common. Daylight may mean either 6000K or 5000K. Bulbs around 4000K (Cool White) are rare, but I did find one CRI 82 100W-equivalent in this color.

Some dimmable CFLs are available, but these bulbs are uncommon and may limit the choice of color or intensity.

LED bulbs at present (Summer 2014) are limited to about 60W-equivalent in omnidirectional form (as opposed to spotlights). These produce about 800 lumens, and are quite expensive (US$10 to US$20 each), so for now LED bulbs still seem inappropriate for valence lighting. But that is likely to change.

Benefits:
- Low-cost fixtures.
- Easily dimmable (use of CFLs may limit this).
- Ability to upgrade to LED-based bulbs in the future.

Problems:
- Uneven lighting, particularly if mounted close to layout.
- Heat if incandescent bulbs are used.
- Moderately high cost for bulbs if CFLs are used.
- Space required behind valence is larger than for fluorescent tubes.