Any tips for making LED lights look more "natural"?

[irishRR]

I recently bought some LED lights online for my layout. I am transitioning from bulbs to LED because I am tired of ripping up structures to replace burnt out bulbs. 

The lights I bought were described as a "warm" LED, but they are still pretty bright and don't really have that soft warm glow of the bulbs. I was wondering if anyone had any success with applying a thin coat of paint, stain, matte finish or even translucent tape on the diode to soften the brightness and perhaps give it a softer, less bright white glow. I look forward to hearing about your experiences. Thanks.

[mbinsewi]

You can try the paint trick, some places that sell LED's suggest that, that will give you immediate results, if it works, or, you can do what some guys in here do, and put in a resistor with a higher value, so it limits, or dims the light.

I've never done this, just read in here about guys that do that.  I don't know what resistors to use or if I even said it right, as in "higher value".

I'm sure someone will chime in that knows more.

Mike.

[wjstix]

When LEDs are described as "warm white" or "cool white" it's referencing the color of the light emitted. It has nothing to do with how bright the LEDs are. "Warm white" LEDs are supposed to be more yellowish in tint, making them look more like old-style lightbulbs. "Cool white" are going to have a bluish tint to them.

I generally hook my building interior and exterior lights, yard lights, etc. up to a DC power pack (like an old MRC Tech II or Tech IV) so I can regulate the light's brightness with the rheostat. I usually find it works better to not be running lights at full brightness, 50% or so generally looks much better.

Otherwise, yes, you can get transparent paint at the local hobby shop and paint the LED to change the color and/or tone down the brightness a bit.

[wvg_ca]

an easy way to get more 'natural' with LEDs is to make it more yellow, the easiest way way is Tamiya translucent yelow paint over top of the LED..

 

also reducing the voltage applied with a higher value resistor helps to cut down the 'glare' or glow from the LED .. this is mostly trial and error , but a starting point of twice the value is reasonable ..

[snjroy]

I paint my LEDs installed on my locos, either to make them more yellow, or to lower their brightness. 

Simon

[RR_Mel]

I don’t even try LEDs for structure lighting.  I use 12 volt 3mm 70ma to 100ma bulbs and run them on 8½ volts.  I’ve only had to replace one bulb in over 20 years running them at reduced voltage, I have well over 300 Grain of Wheat bulbs.  To me they look much more realistic operating at 70% voltage too.

 

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[BigDaddy]

I've gotten LED's from multiple sources and some warm whites are warmer than others.  Unforturnately I didn't keep track of which came from where. 

My layout is transition era, branchline, so I definitely don't want bright.

I am using  2K resistors and experiement with buck connectors to get just a little bit of light.  I don't have a final recommendation, but I am not unhappy with any of my results.

 

[j. c.]

try scuffing the surface with 200 grit sand paper even if there defused  , then run at lower voltage i use nothing but led's . if its listed as 3.1 volts try lowering the voltage to 2.2 or 2.5. volts . some of the best colored  warm whites i have got are from lights that go on sale after chrismas .

[rrinker]

 Lowering the voltage doesn;t do much to LEDs - they are current devices, so it's the current that controls them. Lower the voltagew much below their rating and they won;t even light up.

 It's commonly mentioned to use 1K resistors with a 12V power supply for white LEDs - well, try something a lot bigger, like 4.7K, or even 10K. This reduces the current and reduces the brightness. But it's a steep dropoff, from, bright as the sun to oops, can't even see it glow. 

If the LEDs are "12V" LEDs, try adding a 1K or even 4.7K resistor. There's already one in the LED, there is no such thing as a 12V LED, the semiconductor chemistry of LEDs is always somewhere around 2.1 to 3.6 volts depending on the color and type, so a 12V LED is just one that already has a resistor to limit the current when powered with 12V. But it's probbaly runnign the LED at or near maximum current, which can be exceedingly bright.

                                       --Randy

 

[BigDaddy]

rrinker

Lowering the voltage doesn;t do much to LEDs - they are current devices, so it's the current that controls them.

With loksound decoders, probably others, it is possible to reduce maximum brightness or employ Rule 17.  That doesn't change color temperature but there is a perceivable difference. 

 I replaced my can lights in my kitchen with LED's and kept the same dimmer switch.  They dim, not that I truly know what happens inside a dimmer switch.

[mbinsewi]

So it looks like the best way to do what the OP wants, is what Stix does, and what I do with my signals. 

Hooked up to a power pack, and control brightness with the throttle.

I forgot I had my signals wired that way when I posted the first time.

I have also used the paint method.

Mike.

[j. c.]

increasing voltage on a led increases current hence decreasing voltage decreases current , grant we are talking a very narrow responce . 

[irishRR]

So I have been taking in all of your suggestions. Thank you. I do not have any resistors or a dimming throttle device, but I think I will invest in some. I was playing around and I found that if I apply kapton tape to the diodes on the LED strip, it softens the light and adds a nice golden glow to the light. I did a couple of layers of the kapton tape and it actually closely resembles the look I was trying to achieve. Thanks again... I'm determined to figure out resistors and how they work, but its intimidating. I don't even know what all the different color bands on the resistor mean... but I imagine that is a topic for another thread....

[j. c.]

     http://www.resistorguide.com/pictures/resistor_color_codes_chart.png 

[Santa Fe all the way!]

Tamiya makes translucent paint in a few colors. These are commonly used for lights on model cars. I have the amber(orange). You can try a coat of that. 

[hon30critter]

Santa Fe all the way!

Tamiya makes translucent paint in a few colors. These are commonly used for lights on model cars. I have the amber(orange). You can try a coat of that. 

My experience with tinting LEDs with Tamiya amber is that it doesn't work in all cases. If the LED is too 'blue' to start with then what you will get is a greenish yellow that doesn't resemble anything close to an incandescent light. In my opinion it is best to shop around to find LEDs that are truly warm white. I have found a few. Sorry, but I was too stupid to properly record the source at the time. My bad!

Dave

[khier]

It is not quite clear what do you mean by "natural".

If it is the color, use warm white LEDs. If this is not natural enough, try yellow LEDs or applying clear yellow/orange paint.

If it is the brightness you are worried about try to reduce it. The proper way to control LED brightness is to use PWM (a series of pulses of controlled duration). You can find such devices on Ebay or AliExpress to control LED strip. Many of them are controleld remotely with infra red remote control for your convinience. Or you can make your own control circuit using 555 timer chip. These chips are dirt cheap and allow you to vary the brightness between 50% and 100%. A third option would be to use a micro controller (like an Arduino) but this will be an overkill.

Lastly you can use a resistor in series to choke the current and to control the brightness. Typically you need ~500 Ohm resistor to use white LEDs with 12V source. If you double the resistor value you will get half the current passing through the LED. Choose any value between 500 and 1000 ohm that creates the effect you like.

 

Regards

 

Walid

[-E-C-Mills]

Maybe you could get a variable resistor and and adjust the resistance until you get the amount of light you like?  Then you can buy the fixed resistors to match.

[gmpullman]

irishRR

I do not have any resistors or a dimming throttle device, but I think I will invest in some.

I have a bulky, old "decade box" which allows me to select a set amount of resistance.

DC_test by Edmund, on Flickr

 

-E-C-Mills

Maybe you could get a variable resistor and and adjust the resistance until you get the amount of light you like?

 

I've since picked up one of these handy boards which does the same thing as that big decade box:

https://tinyurl.com/yyurm6qh

Wire this in series with your LED and supply it with the same voltage you are using for your source. Put the jumpers where the light level looks pleasing to you and use the closest equivalent resistor for your installation.

Resistor_7decade by Edmund, on Flickr

 

Piece of cake 

 

Ed

[joe323]

I have the opposite problem have two old life like Exxon gas station signs that I need to replace the old incandescent bulbs with micro  leds to make the sign look more white.

[EM-1]

We played around a bit with trying to control LED Brightness with variable resistance in one of our products, found that the only real way to get a decent control was to use a pulse width modulated voltage source.  With the pulse width varying from anywhere from about 100% on to about a 20% on, 80% off, the control was almost as good as a pot with an incandescent bulb.  But a bit pricier and more complex.

[Bayfield Transfer Railway]

First, run them at less than 20 ma to reduce brightness.

Second, a wash of orangeish paint.  Theater people call this "bastard amber," and it's a standard color to "warm up" the harsh bright theater lights.