RGB Paint Mix Experiments & Discussion - Page 6

It must have some impacts as they both create the resulting colored image in toally different ways. I too have never heard of a screen that was tuned to DLP vs LCD but it might be interesting dicussion point to research.

Benven

I hope it didn't come across that I was saying you wanted a shoot out you asked for the comparison in post 164 and commented in 166 , 170 to me it was a side by side and I didn't see anything wrong with it other than the test was against the one with the black base. (and I saw a rebuttal coming) I did call it a mini shoot out and I tried to explain that its reasonable to compare something good against the excepted current best solution.
Sorry if my wording wasn't the best. I read thru about 50 posts to this thread in a row and the last barrage set me back to days of old.

I'm with you after the paint over glass experiment I don't really think it matters white black or mirror if there is 4 rolled coats on not enough is getting thru to matter and really not much coming back out.

In fact if you remember I was the one asking months ago someone else with spray equipment just go ahead and paint a sheet of glass and see what projected light makes it thru. Tiddler finally picked up on it and now we all know how much gets thru rolled paint.

The more important thing that came out of today's talks to me was this communication of how to best view these comparisons fairly.

Lastly I'm running a Sharp XR10X DLP

Yeah, I forgot about that request. That was a genuine request with no dark, devious undertones. Since RS Maxx is often used and touted as one of the best solutions here, it should be used for comparisons. When you're at the top of the heap, you have to expect some side by side comparisons to see how other solutions stand up. tiddler even said that it was the best DIY mix he tried. That's a good thing. Maybe he will change his mind as he continues through with this journey. Maybe he won't.

And bud, we're good. I just didn't remember asking is all. I didn't feel like checking my posts and I'm glad tiddler provided the link.

From what I see, nothing has changed my mind about the RGB method. tiddler definitely showed us a thing or 2. However, can we prove or not that RGB is a better method for ambient light viewing? That is other than making a gray paint? Metallics better than pigments? Clear bases better than opaque bases? Powders better than paints? White substrate or mirror? I see this as a design of experiments. Let's take what we've learned thus far and apply best practices to it and go from there. tiddler, can you draw any conclusions from your work? I think a quick summary from what you learned, so that we can all regroup and see what the next steps should be, would be a good thing. At least for me.

Here here and if it ok I would like to continue on in the roll of Devils Advocate.
Don't take it personal anyone but as an indicator of when you really have something you will know because I'll be the one Yelling they figured it out.

If you have the mental fortitude to do a recap Tiddler one would be great to regroup on.

Tiddler,
Here is the link to the place where I bought my mica powders. They are very reasonbly priced, too.

I also remember seeing a sample pack of mica powder made by Pearl-ex (I think) in Michaels a few months back. You may want to try that.

I thought that the goal was to find paints that contained pigments that gave the best and brightest test results under the matching color projector light and gave very dark to black results under the other two colors of projector light. Why limit ourselves to what someone else did and find out for ourselves? I promised myself I would try not to make any more assumptions on this forum, so I won't make any assumptions about why or why not someone else used particular paints. For all I know, they might work great.

Tgreenwood

I would have to concurr with the Blue and Blue green push with the pany 900 LCD PJ and light grey paint.

I use Dulux Thomas Tallis 474 currently, after talking to dulux tech, they actually recommend this as a screen paint.
Thomas tallis 474 mix is white base, 1 litre with 8 points black.
Equals 3.55ml black to 1000ml white

Based upon Dulux mix data of 28.4ml=1 yield =64points

I can get the blue under control by adjusting gamma and Blue contrast/brightness using the DVE grey ramp.

This is of course completely screwed the moment a movie has a blue filter over the top of it to create mood. Which is most of the time.

Actually the only time that 2/3 of the pigments will be showing black is when the projector is only projecting a single pure RGB color on the screen. That doesn't happen very often. (When they say 16.7 million colors in the specs, they mean it) Most LCD projectors have 3 LCD panels, one for red, one for green and one for blue. The red,green and blue images are combined by a dichroic prism and the full color image goes through the projection lens. The red, green and blue images overlap each other. If you have white in the image, all of the rgb pigments will reflect their respective colors and you see white. A nice sky blue is red-133, green-193, blue-243. The color of my lemon-yellow truck would be red-255, green-255, blue-62. See what I mean?

If you have a 3-chip DLP projector, the same holds true.



I don't think the number of pigments in the paints makes much difference as long as it shows up brightly under its respective projector color and darkly under the two other colors. If it doesn't show up brightly, just choose another paint and test it.

Tgreenwood

I'm sure gonna avoid fluorescent lights, the spikes look like they are right in the middle of the RGB ranges a projector produces.

Tgreenwood

Tgreenwood

Most of my comments have based around my projector a single chip DLP and we could be seeing maybe a big divide here based on LCD vs DLP with the research into RGB screens. My DLP only puts out RGB color light and makes the millions of colors by rapidly projecting combinations of the 3 colors in a repeating pattern. So in the case of single chips DLP's if the pigments are matched to projector they will be on or off. LCD is a totally different animal you are correct. I think anyone testing ideas will have to keep this in mind.

Very good point you make.

I don't know if you remember back a week or two but I proposed a line of logic similar to what you just posted. And its something I'm currently working on or getting ready to anyway. No one replied to it so I'm thinking it went unnoticed.

And actually I was thinking of both ideas in one. First the over power projector then combine that with both gain and efficiency increases. These 3 things normally would be counterproductive to each other. Without the fourth factor, that being a very dark very thin topcoat.

I read your analogy again yesterday about the car window tint and this is a little bit in my thought process here. That and how I believe RS-MaxxMudd works. I have not came out and openly said light fusion doesn't work as some have although I think roll painting 4 coats of a thick mix over a mirror is not going to produce much of an improvement in image brightness. My idea is a form of LF that takes place in the paint and in part this happens in all the metallic mixes now. The level I see taking this to, is one of more control as to how these metallic particles are placed into the paints. As it is now we are limited to how much metallic can be added. The reason being it migrates throughout the whole mix and if too large a percent of the mix is metallic or the size of the metallic is large we get all kinds on sparkles and bright issues with the image.

Now keep in mind I'm thinking outside the box here and talking in theory I haven't had time to yet put into practice.

We know rolling is the method we want to employ to get these paints on if at all possible. We know that even with thinned paints at about 3 coats not enough is coming back to make it worthwhile. We believe spraying can deposit thinner coats and help the cause.

I'm envisioning a first coat of thick paint made up of clear poly and a very high level of large metallic particles. I don't know what they are yet but I'm thinking silver glitter. The mix wants to be thick enough that the metallic doesn't lay flat to the substrate but stays disordered. (a combination of Benven's flat white for spreading the viewing cone and MM mirror backing) but not a flat mirror and not a mirror behind plastic or glass. A front surface mirror with a light scattering surface. That will fulfill the efficiency part of the plan. The second coat could be an intermediate coating containing things we need to correct. I don't know what will be in it but it could contain finer metallic and pigments (maybe RGB's) in still a clear poly base.

The hope here is that these two layers will alter the light as needed stop all light from going past and redirect as high of a percent of light back out as possible.

Now for the top coat. What I'm hoping for is a light fusion to take place within this layer and also an ambient light absorption and rejection. Absorption caused by the dark shade and rejection by some sheen. It also has to be thin. Do I know what's in this layer yet? Heck no. I believe it has to be the finest of pigments mixed with the thinnest of base. It needs to be something like lampblack that can make a outward darkening to the mix but yet be a small percent of the total mix to allow light to pass thru it that's where the light cannon comes in. thick enough to obscure what's behind it under low light shots but thin enough to let projected light thru. It comes back in my mind to this ratio of the power of the projector vs. the power of the ambient. Eat up the ambient in the top coat but let enough of the projected thru and then without making that projected light work to hard within the paint come back out strong still.

I also am contemplating how do you paint with a brush or roller such a thin precise layer. And I'm thinking of super thinning the mix. Another what if here. But what if a paint was thinned to the point where it took 10 coats to give you the build up of one normal coat. Would it be possible then to improve our quality and still use mundane methods.

Like I said all unplowed ground here. But give me your feed backs.

Why not a couple thin coats of Silverscreen over a mirror, just enough coats to reduce the total mirroing effect but still provide some life fusion effect. Siverscreen would be relatively nuetral overall would it not as a top coat, helping to improve blacks with some added ambient light use as it is grey?

Or possibly a frosted mirror to aid with diffusion more? Or perhaps a sheet of aluminum. Just a thought.

I would like to try reducing the UV and IR light and leave the visible light alone. If we can design a coating so that the relative phase shift between the upper and lower boundary of the coating is 180 degrees. Then destructive interference occurs canceling the light before it exits the surface. Some math should allow us to calculate what needs to be done. Making it is another story

1. Silver Metallic MMud (circa 2003) is essentially what Bud is describing. It produced the first "light fusion" of sorts, but was never called such. Application issues with the OVERLY thick Behr SM led to the early use of Mylar, then Glass Mirrors, then Acrylic Mirrors. These apps however required a Spray job. But for a spell, it was acknowledged that the SM basecoat did a wonderful job of both increasing CR levels as well as ambient light viewability. But why bother with trying to mix "Glitter" into paint? Such has been attempted several times before with pretty dismal results. (spotty, non-uniform mixtures) Using the Delta SM should be strongly considered instead these days for it's of a lighter hue and easier by far in "roller" application potential than any special mixture of seperate components or the Behr SM. Cheaper too. But if you roll on the Top Coat, it had better be in thin coatings using a VERY low nap roller. Apply the paint until you "think" you cannot see any trace of the underling SM. MMud already had pearl in it, but also Deep Base, so a new mix with more "White" or some RGB induced Grey might make coverage a little easier than the translucent MMud.

2.OMG. Do NOT consider SS on a Mirror. It is FAR from neutral. A Bombidil Neutral Grey darkened slighty would be far more applicable.

3. Rolling a mirrored LF screen IS doable if you use Foam rollers, and dry-roll on the first coat. I've done two bigguns before in Indy, as well as two in Memphis, and made comment that thinned BF mix rolled quite nicely sometime ago. But as in any such endeavor, the skills of the painter will determine just "HOW" easy or hard it wild be. Also, knowing when to stop painting, on a mirror or any other substrate, is the key, not the ability of the paint or substrate to deliver the goods.

4. Best of luck with the First surface approach. As far as I know of, I'm the only one to accomplish a working prototype of a FSLF, and it gave me absolutely a terrible time of it. 3 redos of various thicknesses of coatings...ALL sprayed, before I nailed it. The efficiancy you speak of Bud is not a freind in a FS application, for it really only increases the probability that you will not hit the right degree of opacity before you go beyond it. And that was with "spraying" and it's more precise laydown characteristics, But in retro-think, I never had the luxury of using a darker hued "Grey' paint, or one like BF with RGB and other ingrediants to mitigate the intensity of both the projected light as well as any returning light.

But also, as far as up to recently, FSLF images posted on AVS were hands down the best ever presented. No one disagreed with that, and that alone speaks volumes on this forum. But as sated previously, it was a royal PITA for me to produce, and would have been prohibitively expensive ( Plaskolite 'donated' to me a 4' x 8' Plexi FS Mirror that would cost $400+ So just as soon as I posted the images, I also strongly advised the app be dropped from consideration. Since then, Mylar, and aluminum, both polished and matte have been tried, with varing successes. And some abject failures too.

Applying any paint onto a FS Mirror involves doing so on top of the special protective-transparent coating that a FS Mirror MUST have to protect the silver coating. It does not want to allow paint to "tooth" so the first layer must be exceedingly thin and dusty, and with the thin to almost watery mixes we are now using, not getting a run or drip will be pretty hard to avoid.

But go for it. Just be advised....................

Here's some info I found in a quick search....

Spectrum from yellow-green LED from radio shack
yellow-green LED

Spectrum from 1W Luxeon LED Desk Lamp
LED desk Lamp
(Halfway down the page)

Spectra of miscellaneous Colors of LEDs
Misc LEDs

Spectrums of miscellaneous sources including Fluorescent, a CRT monitor and an LCD from a digital camera.
Other Sources

From what I've been able to find, a yellow bug light is just a regular flourescent with an added phosphor to emit yellow. See Light as a Tool pretty cool.

Don't know about the others. I will keep looking and see what I find.

Tgreenwood

OK...so at least you have been doing some past reading so you know wherein I speak. Yeah.....I hated that Roller. But actually, when flattened out and used like a Mop, it produced a very smooth, featurless finish. One far smoother than it did 'sucking up' that gooey SM on every return stroke. Now if i would have had the confidence to thin the behr, perhaps things might have gone a different route, for I always followed Paint Mfg's directions back then and Behr did not reccomend using more than 4 Oz. water per quart. That much made almost no difference.

Ahhhhh..........., the good ol' days. Fergitabowdim!

I am an electrician, and while at work today, I was hanging a customer's light fixtures. They had purchased the GE reveal bulbs for the light bulbs. I read a little about them and noticed that they use a mineral, neodymium, to absorb yellow light. Does anyone know of any other minerals that will absorb colors of the spectrum, because maybe we should be looking to them rather than pigments to satisfy this venture.

Sorry, I just did a little more reading and realized that neodymium is a chemical element and not necessarily a mineral (from my understanding), but regardless, are there any of these out there that we can use?

I thought that this may be of some value to us. It is Sony's chromovue screen patent. I haven't read all of it, yet, I will try to finish it in the morning.

I was looking at the software that came with my Spectrocam spectrophotometer and it allows me to measure the following:





I could then compare between lamp black grey and RGB grey and see which sample rejects more light. The pictures above are my LCD screen of my laptop.

rfisher1968: Please clarify - are these the measurements of an all-white screen on your laptop?

Garry

Not full white LCD screen, just about 1/4 white and about 6" away. I just wanted to show the pictures as an example of what an how it could be compared.

Maybe i'll just compare BOC and the RGB screen I already made. It looks like i'll be able to calculate gain and show if there is ambient light rejection.

Well just measuring gain difference, the BOC was about 55 candela/m2 and my RGB screen was about 165 candela/m2. From those measurements I would say roughly a gain of 3.0.

As for the ambient light rejection, my RGB screen shows 3 spikes 1 at purple/blue, another at green/yellow and 1 at yellow. What was very interesting was no spike in the red area. This was measured with about 120 sq/ft of windows wide open, full light, but no lights turned on. The first 2 spikes where very large and the yellow was very small. I considered the yellow was coming from the ambient light from the windows. I then turned on all 6 can lights and took another measurement which very little of anything happened. The graph looked just a slight bit different.

From this quick look at the RGB screen I would say the RGB pigments I used are aiding the rejection of ambient light. How much it is helping, I will hopefully find out soon.

Next I will use the spyder pro 2 and calman for more measurements.

Pictures of the graph to follow soon.

How did the BOC screen do at ambient light rejection with your spectrometer? It might be good to use as a baseline measurement to judge other measurements against.

Tgreenwood

Just an update on this and my post about going to the source... I didn't see any follow ups or further comments on this, so maybe it's not a matter of focus or interest, at least not now...

All the paints at Home Depot are mixed using pigments from one company... it doesn't matter if it's Behr paint, Glidden, or Ralph Lauren... they all use Behr pigments. Now the question is if it's possible for a consumer to get ahold of just the pigments or at least a list of what they are. I think I'll track down a number to Behr today and just call them and ask

I know Tiddler has said several times he feels the ultimate goal and result in all this research and testing should be something anyone with a little motivation and desire for something more than a simple one step solution can go out and get the materials and mix/apply this themselves.

Reverse engineering was mentioned before and that seems like a great approach. It makes a lot of sense to start with the source and figure things out from there, then back it off to a more easily obtained and applied method. I said this earlier and I think Prof might have confirmed this thought, but using paints that are premixed will throw in additional elements that could make things more complicated and harder to control.

Now back to our regularly scheduled programming

The best thing that I could do is just post the pictures of the BOC in different lighting and compare to a RGB screen. Also If I get the time compare the RGB screen to a screen with the same mix, but with no RGB pigment.

I think taking digital pictures of a screen is really not a good way of determining anything. Let a more accurate spectrophotometer do the job and scientifically prove or disprove the RGB screen theory.

At last what this effort has always lacked, some science.

fisher1968 please keep up the good work.

For those who may be interested in making their own paints from scratch here is a link to a PDF that has instructions and a product listing including cost of the various pigments. Be warned they carry a huge inventory of pigments.

http://www.guerrapaint.com/PDF/Guerr...nt_catalog.pdf


The actual website for reading up is located at;

http://www.guerrapaint.com/