LED Strip Layout and Power

Before digging into the led light and power issues further, I would suggest you consider mounting the strip(s) at less than a 45 angle (from the horizontal) or at least doing a mock-up to see how the lighting works. (See Ken Rickman's photos below and his My results with LED layout lights post for additional info). Although the lights have a 120º Beam Angle about 80% of that light is in a 90º arc. If you end up using multiple strips you may get better results with one of more strips mounted horizontally (0º). Note that if the inside of the valence is reflective (I have used gloss white paint and even aluminum foil), the light from flat mounted LEDs will reflect off of the inside of the valence distributing the light.

The big question here is how much light do you want (again see comments in Ken R's post). If you are not going for photo quality lighting (800 to over 1000 lux as on Michael Rose's Georgetown & Allen Mountain Railroad), you can get away with 300 to 500 lux (range recommend for office lighting). Measurements of inexpensive 3528 LED strips specified at about 130 lumens per foot averaged about 200 lux at 0.5 m (~ 20”). So if the strips you are looking at actually produce 280 lumens per foot (See note below), with your strips mounted about 18” from the front surface of the layout and18” to 24” from many layout structures, you will probably find that two strips should more than meet your needs.

So what does that mean for power? You may need a lot less power, but to be sure I would mock-up the lighting before installing the final wiring. But:

Note: Michael's LED boards with 21 5630 high output LEDs only generate about 670 lumens per foot and some of the best high quality commercial 5630 LED strips are only specified at about 480 lumens per foot. As noted above the 3528 strips I usually work with are specified at about 130 lumens per foot, and the 5050 strips I am currently working with are specified at a little over 200 lumens per foot. The 280 lumens per foot number is closer to the typical lumens per meter number specified for many 300 LED 3528 strips and still double the specification of many 600 LED 3528 strips. If the strips do not actually produce the 280 lumens, you may need that extra power and wiring.

Images from Ken R's post (Thanks Ken):

Lumens

The LEDs I'm looking to purchase are $119 USD for a 16' reel. Flex Fire claims they have the brightest LED strips on the market. At that price, I hope the strips are as advertised. If anyone has used Flex Fire before, I'm interested in any reviews you might have.

Here's the website address.

http://www.flexfireleds.com/

Flex Fire strips

Browsing FlexFire web site for $119 strips I found these: http://www.flexfireleds.com/colorbright-bright-white-by-the-reel-led-strip-light/

According to their specs they aren't anything special. Overpriced yes, overly bright no.

You might want to shop around some more.

Expensive Strips

I would hope at that price they come and install the strips.

That is actually not a bad price from a Higher End lighting supplier (with their architectural series costing at least twice as much), but before going with Flex Fire at $119 and 4,595 lumens per 5 m you might want to check out other suppliers. For example:

12 Volt Flexible LED Strip with 300 SMD5630 (Final Sale) 8000 lumens $50 on sale (regularly $100)

With these 5630 strips I am measuring over 1400 lux at 0,5 meters and about 700 lux at 1.0 meter. More than enough for a shadow box layout. They are currently only listing the Warm White (3100-340 K) as available which is lower than the 4000K - 4500K listed for the Flex Fire strips.

Or:

12-Volt High Output UL 16.4-Feet Flexible LED Strip with 300xSMD2835 48-Watt 3650 - 4100 lumens $49

With these 2835 strips I am measuring over 500 lux at 0,5 meters and over 200 lux at 1.0 meters. One strip maybe right on the edge of your layout lighting needs, so a second strip could be necessary. But they are available in Warm White (2800-3100), Neutral White (4100-4500K) and White (6500-7500K).

Note: When we need to install two strips, we often use a Warm White with a White so that we can adjust the apparent color.

Product Comparison

I did a comparison of a few more LED strips. I looked at a couple companies, amazon, and LED wholesalers, and compared a few of them. It seems there are definite trade-offs as the price decreases, such as dimmability, CRI, Final Sale (can I get more later when I expand the layout) etc...

There is also the question of will the cheaper LEDs perform as described? There's a few posts on this site of the strips underperforming. I'm a firm believer of 'you get what you pay for' most of the time. Higher performance would mean needing one strip instead of two and saving money (or only spending a little more for a higher quality product, instead of double).

LED World might be a better choice than FlexFire as I live in Canada. I will save on shipping and get a similar product. I'll have to confirm their color temps though. Their 5050 strip looks better than the 3528 but it will require me to spend a lot more on a power source. I'm not sure they gave an accurate description of the LED/ft on the 3528. It seems very dense. Their website lists the 3528 as having 120 LED/m.

Buyer Beware

Doesn't hold water in the LED world unless you by MIL spec. You are going to get China made LEDs regardless of where you buy them.

Choices

Following that advice then I think I would look at the SMD 5050 from LED World in Canada. They have almost double the lumens at double the price per foot as the 2835 from LED Wholesailers. I would likely only need one 5050 strip with less than the power requirement of two 2835 strips and a higher CRI and a 2 year warranty. I would also save on shipping.

The 5630 from LED Wholesailers wouldn't be bad but they have a large power requirement, no warranty, final sale, and a little warmer color than I'm looking for.

Good Comparison and Analysis

Joe, Did not realize you were in Canada, or I would have directed you to LED World. My bad.

You have done a very good comparison of some options. For additional incite you might want to add two more cells to each column: Lumens / $ CAD and Lumens / Watt. But I have to agree with Alan Buyer Beware. For some museum displays we originally purchased some High End Architectural strips from a reputable lighting dealer and were greatly disappointed in there performance and quality. The dealer did take the strips back and found some inexpensive strips which actually out perform the expensive strips. Other than sale items both LED World and LED Wholesalers have provided good service readily accepting product returns.

I have tested and have installed the LED Wholesalers strips I referenced, and have found them well made and up to specification. Note that the LEDs used on the LED Wholesalers 5630 strip are from the same manufacturer and series Michael Rose used on his custom boards. I have only worked with color and RGB strips from LED World, so I do not have any data on their White strips.

Strips with 120 LED/m (600 LEDs per 5 m) are available from many manufacturers. One of the strips I have worked with is the 12 Volt Double Density Flexible LED Strip with 600xSMD2833. 4100 lumens for $49 is not a bad deal either.

You need to be careful with the Waterproof (actually in most cases Water-Resistant) strips especially the Silicone Gel molded strips, as the silicone acts as a lens significantly reshaping the light beam. For some strips we found that the silicone lens broadened and dispersed the light, but with most we found that the lens narrowed the beam significantly. I would also skip the sleeved strips unless you want a diffuse light at significantly reduced intensity (from our measurements about a 20% loss).

Have fun with the LEDs and the layout. Please keep us updated on your progress.

Questions

Ken K,

When you said I might need to try mounting one of the strips at 0º  did you mean against the valence or against the top of the module? If most of the light is in a 90º arc, is it centered or closer to one side of the strip? If it's to one side, is there a way to tell before installation, or is it trial and error?

Many thanks to you and Alan for the replies so far.

LED Strip Mounting

By 0º I was suggesting that the strips may be mounted to the top of the module with the light directed straight down. If the strips are mounted close to the valence a significant amount of light can be reflected and diffused off the back of the valence. For museum displays at times we have to get very creative with lighting, and for a few displays we have actually mounted strips to the interior vertical (valence) surface of a display cabinet. The illustration(s) show how we have typically mounted strips to better direct and distribute the light. Before installing LEDs in displays we often tape or tie-wrap strips to thin wood strips and play with various possible configurations. We have also, due to the directionallity and color of the LEDs, installed multiple strips (including color, color adjustable and adjustable RGB strips) to get required effect(s).

Below is an intensity plot from a typical surface mount LED showing that most of the light is emitted in a 90º arc (red lines) with the peak energy perpendicular to the surface of the LED. The lens effect of the silicone enclosed strips can further reduce this angle by about 20º. We found this out when installing strips for fish tanks where we had to add additional strips to ensure even lighting to all sections of the tank

what you pay for = "bin-ing"

An additional consideration

If you use multiple strips each with a different temperature then where the beam falls may produce unexpected results. You need to experiment if this is the case.

This occurred in my application. I use 5000K CFLs as the lighting workhorses. It would take a whole lot of LED strips to match their luminosity and at $2 each they cost a mere fraction of LEDs. I use 6500K LEDs to fill in the missing color gap - above 5000K. CFLs are expensive above 5000K. LEDs become very cost attractive at the higher temperatures.

I discovered that when the LED strip was placed at an angle (Ken's illustration) the beam was intense at the bottom of the backdrop. It made my sky blue much bluer. This produced an upside down sky effect - it was bluer at the bottom than it was further up. By mounting the LEDs pointing straight down the effect went away yet my lit layout area still had the touch of blue light needed to compensate for the CFLs deficiency of blue.

It was my lesson that illustrated what Ken is describing above with his beam diagram. Be aware of this. You can use it to your advantage.

You can see my lighting color experiment here: http://www.lkorailroad.com/lighting-proof-of-concept/
You can see all the posts on my lighting installation here:  http://www.lkorailroad.com/category/layout-lighting/

Understanding

Ken, Alan,

For my own understanding, do the pictures here illustrate what's happening at 30 or 0 degrees? Will the light reflected off the valence create more intense light toward the bottom left and bottom right? More so than at 45 degrees where a lot of the light is 'lost' toward the sky in the upper left?

Mockup is only way to be sure

Yes.

Maybe. Mockup to be sure. Build a cardboard version and test until you are satisfied.

Below is a single strip of 6500K 5050-300 LEDs mounted at 0° angle 21" above 24" deep benchwork with 3" fascia reflector height. Very similar to your second illustration.

It's your layout lighting

It is always frustrating when a question is (essentially) answered with a question, but I have to agree with Alan: Maybe. Mockup to be sure.

You illustrations show the expected lighting patterns, but it is hard to predict what the actual light distribution will be from specific LEDs strips mounted in any display. Given the adaptability of human eyes and brains it is difficult to predict how display lighting will be perceived by viewers and even more difficult to predict how light at some color (temperature) will be perceived in a specific display or setting.

It comes down to you finding lights and mounting configurations with which you will be satisfied. There are many posts on the MRH forum discussing tearing out sections of or whole layouts to meet the owners need. We would all like to get it right the first time, but sometimes we have to do it over. Experimenting / mocking up various mounting configurations could save you from having to do it over.

Front Lighting is Important

One thing I see that needs to be addressed is the amount of light hitting the front track. because your valance is even with the front edge of the layout, your light will fall directly down on the front track creating a shadow on a anything at the front of the layout. I recommend allowing the valance to extend forward a bit to throw light on the front of the track and forward scenery. 

I believe in doing a mockup, i did it and am very happy I did. Just make sure to place temporary track, train and scenery mockup (tree, building, people) and various points while doing the mockup. Keep and eye out for shadows and dark areas at the front.

I did a few articles on shadowbox and LED lighting on my blog. See the following for additional information and ideas:

Variable LED Lighting - http://smallmr.com/wordpress/small-display-layout-with-variable-led-lighting/

Shadow Box Shelf Layout Design - http://smallmr.com/wordpress/modular-design-for-a-shelf-layout/

LED Power Supply - http://smallmr.com/wordpress/old-computer-power-supply-conversion/

Layout with design for overhang lighting - http://smallmr.com/wordpress/mound-city-1862/

I've tested a front valence and LEDs

If your LEDs are mounted right behind the valence and your valence is even with the front of the layout, LED stripes are so thin that given recommended practices of having your track back a few inches from the layout edge, there is no shadow. You can even mount one strip pointing down and another right above it pointing at whatever angle you determine is best (45, 30, etc).

Certainly a CFL tube at the front is going to create shadow, which is what the old adage of sticking your valence out comes from. 

Good Points

I'm going to spend a little bit of time deciding how I will modify the existing bench work to turn it into a shadow box. It probably doesn't have to be as bulky as I have it drawn above. I can make the valence 1/4" hardboard flush with the fascia mounted to 1 x 2 framing in a configuration that allows me to mount the LEDs in line with the front edge of the benchwork.

Price of Ribbon Lights

Paying $119 for a reel of LEDs is throwing money away.  You can find 600 SMD 5 meter reels in any number of colors for less than ten dollars that will do what you need done.

George

User of LED Ribbons lights for years . . .

LED Striplight

Since most of these LEDs are made in China why not go to the source. Aliexpress.com have these and more - most with free shipping. All colours, brightness, lengths etc.

"Overhanging" lighting fascias VS transport/storage issues

Dear Marshall, NYDepot,

While a roof/lighting valence which extends beyond the scene base is logically and lighting-wise advisable,

http://www.krmodels.com.au/module.html

it immediately causes problems in the construction material/quantity calcs for a given module, and also causes stackability/transportation issues for said modules (not a "square" end profile = does not "cube" well in vehicles or storage spaces).

Agree with NYDepot, and with numerous "proscenium" show layouts as supporting evidence,
it is entirely possible to avoid _obvious_ front-edge shadows with adequate scene design and lighting treatment.
("Brooklyn : 3AM" required an additional extension light-shield because there was _too_much_ ambient light falling on the leading-edge of the scene...) 

I would also note that with 120-deg beam-angle LED strips, issues of "arraying" the strips to get adequate even coverage are almost eliminated. A quick spin with the MRH search engine will provide pics of "Toorong", using 2x LED strips mounted @45 degrees, more than adequately punching-against ambient/daylight, on a 1' deep x 2' tall-profile proscenium module. FYI, the inline dimmer had to be left at a setting of "3" out of a possible "8 = max", because Max was simply Too Bright for the scene and most typical indoor ambient-light situations!

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Results

So I bought a 150W power supply and DC dimmer from Flexfire LEDs and bought 4.4W/ft 5100K LEDs from LED World. I built up the layout sections into a shadow box design (minus the roof, that's still coming, will be painted sky blue like the upper part of the backdrop), and mounted the LEDs on 1/2" x 1/2" square dowel at 30 degrees. Just one strip turned out to be very bright. I took some photos with them dimmed slightly. I'm not camera savvy so I set our Canon Powershot Sx40 HS on Auto. Here are some photos. The last section with the bridge in the corner does not have any LEDs mounted on it yet and is noticeably darker.

With no other light coming from, or into, the room:

Rooms lights on:

Mounting:

Looks Great

Joe, the lighting looks great with minimal shadows on the backdrop and nice even lighting of the cars on the front track. When you get the roof on all of that light escaping through the top will also be directed down into the layout.

If possible could you look at the shutter speed and aperture metadata for the second photo so we can get an estimate of the light intensity?

Photo Properties

Ken,

Thanks for the compliments.

I made need a quick tutorial on how to get the info you're looking for, but this is what I pulled off the "Details" tab when I clicked on the "Properties" of the photo:

• F-stop: f/2.7
• Exposure time: 1/30 sec.
• ISO Speed: ISO-320
• Exposure bias: 0 step
• Focal length: 4mm
• Max aperture: 2.875
• Metering Mode: Pattern
• Flash mode: No flash, compulsary
• Subject Distance: About 8 ft away - no data here on the photo.
• White Balance: Auto
• Digital Zoom: 1
• EXIF version: 0230

Resolution is 180 dpi vertical and horizontal. Bit depth 24. I compressed the image down to fit web pages from its original size.

These particular strips were advertised at 396-418 lumens/ft.

Hope this helps.