Why LCD Backlighting Won't Work for a Black Blade

[TheSilverDark]

First, I know black blades aren't possible from a physics sense, and I'm not talking about a true black lightsaber.

I was curious as to how computer moniter produce light even when they are showing the color black. My understanding is that it is back lighting and LCD display. I have no idea how LCD works, so for any of you electrically minded people out there, could you please explain why I would be unable to apply this to tubing (obviously not for dueling).

On the other hand, has anyone tried to back light electrical tape wrapping it all the way around? Not Hampton's method.

Thanks and please don't kill me.

[Mineral]

LCDs (and CRTs and projectors) do not light up the pixels that are "black." There may be some light leakage from the backlight, or it may actually be very dark gray, but, as with every instance of black, darkness/blackness is the absence of light.

[TheSilverDark]

Yes I understand that, but why are we unable to provide a back lighting method to a polycarb tube? Or has no one put in the time to make one, since I imagine poking thousand of tiny holes into electrical tape probably doesn't appeal to people.

[rlobrecht]

For a black blade, we would want the blade to be black, and for the back edge to be lit. The problem I can see is that there is no back edge to a lightsaber blade, at least not one that isn't always stuck to a wall. If I understand what you are saying, you'd end up with a blade that looked like a star field.

[Zacharyah]

LCD stands for liquid crystal display because it consists of crystals suspended in a liquid matrix. As a current is provided to the crystals they deform and change their optical properties, becoming either more or less opaque. For the use in monitors and phones they require light to shine through, either from the back or the side, provided by a separate light source. As mentioned, when the monitor is showing "black" because the crystals are as opaque as possible there is still light leak because they can't be perfectly opaque.
There are flexible LCD screens out there, but the only reason to use one would be if you wanted the ability to adjust the transparency of the blade on the fly. Otherwise you could just use a tinted film with a regular in-hilt LED.
This issue is that even with an lcd film you're not going to get a glowing halo effect, you'll just get a really dim grayish blade, since you won't have edges or borders where the light will leak through more. So, save yourself a bunch of money and just get a black tinted film to roll up in a blade and see if you like the look

[FenixFire]

Well, first to be accurate to the black saber depiction the blade is more of a true blade and not cylindrical and the lighting was on the edges. There are several very good examples I have found on several prop - not necessarily SW related sights that have accomplished the black blade look. The edge lighting would be best accomplished with acrylic, not polycarb, thus a flat blade primarily acrylic = wall hanger/prop piece. This usually turns people looking to do it off because they want the black blade and still full dual worthiness.

Best examples I have seen entail shaping the 1/2" thick acrylic sheet to the shape of the blade (leaving the edges unfinished) then fabricating the "holder" section from round stock. Solvent welding the two pieces. Then sending that out for vacuum metalizing with a black chrome or blackened bronze plating, or priming and painting it with automotive (plastic trim) paint. Then sand and carve the blade edges to shape and reveal the light-piping properties of the acrylic sheet.

[TheSilverDark]

Gotcha guys now. Thanks for clearing that up for me.

[TheSilverDark]

13889

So uhhh...I found this

[darth_chasm]

Can't really make anything out of that pic

[FenixFire]

13889

So uhhh...I found this

Its a 1/2" flat Optics Quality Cast Acrylic sheet cut and carved to shape. AKA. Ripper Blade. Top grade cast acrylic will only allow light to exit where the surface is disrupted or there is an impurity in resin. Photograph it in a dark room with a black satin cloth as the background and you get this effect. Since it is acrylic, it is a show blade only. you can get it in PC but the light piping will not be as good. In real world lighting the center will show slight lighting, but it will give a convincing effect. Figure out a rectangular hilt and custom mount some CREE SMD dice on a rectangular board/heat-sink you could have a nice black saber show piece.

The one shown in the image is a raw ripper blade, minus the after purchase finishing mentioned in my earlier post. There are even better examples on Halo forum where people have used the same techniques for Energy Sword props.

Here is the larger image:

http://i.imgur.com/ZgblMHV.jpg

[TheSilverDark]

Its a 1/2" flat Optics Quality Cast Acrylic sheet cut and carved to shape. AKA. Ripper Blade. Top grade cast acrylic will only allow light to exit where the surface is disrupted or there is an impurity in resin. Photograph it in a dark room with a black satin cloth as the background and you get this effect. Since it is acrylic, it is a show blade only. you can get it in PC but the light piping will not be as good. In real world lighting the center will show slight lighting, but it will give a convincing effect. Figure out a rectangular hilt and custom mount some CREE SMD dice on a rectangular board/heat-sink you could have a nice black saber show piece.

The one shown in the image is a raw ripper blade, minus the after purchase finishing mentioned in my earlier post. There are even better examples on Halo forum where people have used the same techniques for Energy Sword props.

Here is the larger image:

<blockquote class="imgur-embed-pub" lang="en" data-id="ZgblMHV"><a href="//imgur.com/ZgblMHV">View post on imgur.com</a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>http://imgur.com/gallery/ZgblMHV

(Sorry bout crappy quality btw)

The text actually says that this is made with "LCD polarizing film" wrapped around the blade.

Here's a link to Turgon's original thread: http://imperialroyalarms.com/thread/2018/black-blade-phenomenon?page=3

[FenixFire]

(Sorry bout crappy quality btw)

The text actually says that this is made with "LCD polarizing film" wrapped around the blade.

Here's a link to Turgon's original thread: http://imperialroyalarms.com/thread/2018/black-blade-phenomenon?page=3

Actually this is what it says:
"for a dueling blade you have a whit LED and remove the film inside the blade lightly paint it black for a show blade make the blade and paint one side black with a white LED " The later show blade is what he shows in the picture you posted. The previous would block out the light that is transmitted down the tube only allowing the light that pipes down the edge of the blade to be visible.

The Polarizing film is what he shows wrapped around the exterior of the tubes on the post you just linked. If you continue on the saber forum post I believe their is an example where someone took a PC round ripper blade and put the polarizing film on the inside and called it a dark blade or something like that. The polarizing film will work for the effect if you can find a way to protect it with an outer sleeve of PC. Perhaps a wrap a 3/4" PC tube with the film and then insert that into a show blade, assuming it would fit.

[TheSilverDark]

I was considering ways to protect it, but I have no intention of ever using one as a dueling blade :P. It was simply an idea I had and wanted to know if people had tried it or heard of it. I eventually stumbled upon that thread so there you go. I may in the future try to make a duel worthy blade but for the time being I just wanted to see what people thought of Turgon's work thus far.