Ambient Light screen development thread.. - Page 2

can't recall the poster...it was back 4 or 5 years and he just kept taking a few sample to his work place and checking them out....

should we be going for a flat line instead of one that falls off going to the right?

 

spectral.doc 68k . file

I believe that would be no different from a grey screen. I may be wrong, but I would think that you would only want to reflect the three colors and nothing else. In this manner, everything else would not be reflected back to the viewer. KBK mentioned something a couple of months ago about making screens for specific projectors and achieving really good results. Since he has access to high grade pigments, this might have been a lot easier for him.


Ericglo

*I just deleted what I originally said, more conceptual thinking without anything useful lol*

here is something useful and their are companies that can make these coatings for you. In what form and cost and media? paint? liquid? I dunno but here is the keyword I have uncovered so far and it can be tweaked by companies to filter out broadband wavelengths of color or narrowband wavelengths of color, now since we got our bases covered here is the keyword

"Anti-reflection Coatings"

Now what needs to be done, if this is cost effecient, we need to find out the wavelengths that exist in house hold lightings and the wavelengths of various projectors(project a primary color sample). And find out the right equation and trade off to what mixture of coatings will effectively kill the ambient lighting and still allow the projectors colors to pass through(or reflect) and back out without effecting them, or absorbing too much of them as I would imagine the ranges of their wavelengths will probably cross some and if they cross too much maybe placing certain filters over the lights inside will shift the wavelengths to increase effectiveness if necassary.

I can probably find out some more of this by google but we need to work together =)

This may explain MM's delay, it appears to be rather difficult to find small quantities of Anti-reflection Coatings, every site I have been too thus far requires you to call for prices. I suspect when the ingredients of Anti-reflection for each particular wavelength for ambient light is mixed with a Deep Base and applied in layers with a spray gun it effectively kills the ambient light and then if you have a metallic base or mirror under it, it helps the reflectiveness of the projectors wavelengths even more.

Also Anti-reflective coatings may require to be applied to glass to work, such as a mirror, I have yet seen it be mention as being appliable to anything else. But when you think about if you want the other colors of light to pass through your not going to coat a block of wood lol. I assume a clear like Deep Base would have a similar effect as glass though.

Anti-reflectiveness coatings patent was filed in 1999 United States Patent 6172812 and became public in 2001 btw (notice sony's black screen technology was filed in 2002, imo it all makes since now) actually there are numerous antireflection patents from many years back

Also its usefulness in display technology is apparent, they can be applied to CCD chips(the image sensor chip(s) in camcorders), which makes me wonder if the anti-reflective used in lcd displays and laptops and even pda screen protectors are also the same. At any rate it is done for the same purpose, block ambient and even UV and sunlight.

*sorry if any thing I say sound contradictory this is a WIP as I start to pull together more and more information*

This link contains a rather long but complete essay on optics with a lesson on antireflective coatings. I haven't had a chance to read it myself completely but I will when I return from work today. Hope this helps and provides new and valuable information.

http://www.mellesgriot.com/products/optics/toc.htm

I think the anti-reflective films certainly have merit, but I thought in another thread, it was determined that the coatings were just too expensive to be useful. I am much more interested in a paint solution, because pigments, bases, etc. are much less expensive. Perhaps there can be two threads going on--the paint solution, and the film solution. I'd like this to remain the paint solution, if possible.

Same here, I would really like it to be paint. So what is it not possible to mix film coatings into opaque paint and then apply it? I've asked some of these companies some similar questions haven't got a response yet.

I also have looked at the ingredients shown on the list on first page of this thread versus the picture MM has shown of ingredients and on the ingredients list it had said blue green maybe we are seeing blue green there on the table...just a thought from a lurker who has been enjoying everyone's brilliance!

All the A/R (anti-reflective) coatings that I have been exposed to have been to reject reflections of the sun. We use this stuff daily for our outdoor lcds. It is a coating that is "sputter coated" or "vaccuum deposited" onto a piece of glass. You can get get an AR film that they sometime apply directly to a polarizer, but I doubt that it comes in very large sizes. I can try to source some but would need to know what types of wavelengths of light we are trying to keep from reflecting.

The glass we use now is .5% reflective of sunlight. I have tried a couple of pieces over my silverscreen screen but did not get any good shots or outcomes. Maybe it was because I couldn't hold a big 20" diag piece up (heavy).

And yes...this stuff is pretty expensive. Never got any price on coatings/liquid, but a piece of 6mm A/R coated vanilla glass for a 32" LCD will run you about $75 in 100 piece quantities.

I like the approach right now trying to use the right pigments to only reflect the color spectrum from the projector.

Have we nailed down yet exactly what wavelengths of light we are trying to reflect? If so tehotaone ought to update the first post with all the known factors or current state of the mix so it doesn't get lost in the thread since this will undoubtedly get to be an enormously long thread.

According to this Wikipedia entry, the wavelengths (in nm):
Red=625 to 740
Green=520 to 565
Blue=440 to 500

I've also seen more specific numbers like:
650 nm Red
510 nm Green
475 nm Blue

Then you need to determine where along that continuum your projector lcd panels or color wheels are.

Assuming visible light is between 380 nm and 780 nm, a great film would filter out (i.e. absorb) 380-440 nm, 500-520 nm, 565-625 nm and 740-780. In other words it should absorb indigo/violet, cyan, yellow, orange, and the "almost infra-red but still visible." Notice the yellow and cyan in there. That's why I don't think CMY is the way to go. (which brings up the trick question: what is the wavelength of magenta?)

bill is there no way to suspend the chemical of AR on anything but glass? Something lighter, clear gel like substance? or a type of clear paint?

Also do you have access to it and are able to create the specific wavelengths? I would just find it interesting if someone could get even a few inches of it with the applied coatings that would be deemed correct and see what happens, at least we think we know what should happen. But even if it works how are we going to find a new medium it can be applied to that is cheaper and give the same effect?

I found this statement about magenta;

Thus, you will see yellow between red and green, and cyan blue between green and blue-violet. The third secondary colour of light is magenta. This is not part of the spectrum, it has no single wavelength of light, but the sensation of magenta may be perceived by looking at a combination of red and blue-violet light. (It can be distinguished between the two parts of a double rainbow). It is interesting to notice that, with the wavelengths yellow and cyan our eyes decompose the light into responses made by two cones, then our brains recombine them into the sensation of yellow or cyan. That is, we never directly perceive yellow or cyan.


On this web site http://www.abelard.org/colour/col-hi.htm

Pretty interesting write up. For example the primary colors stated in the article are Blue-Violet Green and Red not Blue Green Red..

That's why it was a trick question!


But he did himself say that different people are taught to name colors differently.

What happened to all the "Week-end' painting effort I read about happening? Am I the only fool killing himself breathing in all this crap?

....or has it become a waiting game? Perhaps a search for more answers provided by clues from the pic posted?

It pains me to see this thread receeding downward, so consider this a "bump" with good intentions.

Well I know I haven't given up. I have however decided to go a slightly different route.

I am still trying to make a good ambient light screen, the only differance is I want it to be a roll on application. Most people coming here for screen ideas have no intention of buying spray equipment, have any idea on how to properly use spray equipment, or are willing to spend the money needed for spray equipment. They want a relatively simple, affordable DIY solution, that is what I am trying to create.

I have been in the painting business for 20 years and find this to be quite an enjoyable twist from the normal painting scene.

I am not sure if your (MMan) mix can be rolled or not. I am trying many differant techniques, from one mix to layered screens. I will post results as I see them. Hopefully we can find a good scren for ambient light that the average person can throw together in a few hours on the weekend.

the biggest issue i see with rolled screens... especially when they deal with metallics... is the roller either picking up the metallics or spreading them in less than uniform patterns.

otherwise your absolutely right. 80% of the questions i get PM'd are questions regarding how to roll a particular mix.

Yes the metallic paint are a pain to roll, I am currently trying to use prducts such a floetrol to help make this easier. I am not sure however is such products effect the finished product.

i've been using the minwax water-based poly satin finish with no real side effects instead of floetrol. obviously this will give your mix transparency and too much of it will add some sheen... but i basically use that to my advantage. benven has recently mentioned going with the minwax as opposed to what he had been using. i'm sure he'll report his findings on his recent change. he didn't like the yellowing effect of his old poly.

biglyle, have you tried rolling CG??

Cg?

Yeah, Canadian Gray. The latex aluminum mix.

http://www.avsforum.com/avs-vb/showthread.php?t=593951

Well I have a few screens drying as I type this, will hopefully give them a fast test tonight.
I used almost the same mix as on the first page except I used Magenta, cyan and yellow as my pigments. I played a round a bit with the three until I got a pretty decent grey. I am an anxious to see how it works out.

Sounds like the pressure is a bit to low or the mix a bit to thick. HVLP's can be a real fussy tool to work with.

I like working with about 15psi when I spray with my HVLP, and like the paint to be about the consistency of table cream.

As far as thinning goes, my HVLP gun came with a viscosity stick. Instructions for it say thin paint and test until it drips at 1 drop per second. Maybe that would work as a rule of thumb for your guns.

heres a few pics of a screen I have been drummin up
Small panel in the middle is my mix, the rest of the screen is MMUD-SM
[IMG][/IMG]
full darkness, panel in the middle of screen, cant see it, can you?
[IMG][/IMG]
lights on, room is plenty bright, you can esily sit anywhere in it and read the newspaper. Can you see the panel now?
[IMG][/IMG]
How about now?
[IMG][/IMG]
[IMG][/IMG]

Will post more info as the mix cures and I see results.

Those are some great looking results Lyle.

Not just worthy of note, but worthy of some undivided attention by everyone else on this thread who has note come so far.

Congrats!

Thanks for the kind words.

I know I rode you guys pretty hard over the past few weeks, but I can honesly see where you are coming from now.
I have spent almost $200 in the last five days on paints and supplies, and have painted almost 25 differant samples. Not to mention my house smells like the back of a Glidden truck.
So like I said, I can see where you are coming from and fully understand your desire to make a few $$$ at the same time.
Once I get my finished tweaking my formula I will post more results, its still to early IMO to get excited.

Given that many of us have screens that may not even be as good as your previous screen which is bested by your new sample, maybe a little excitement is in order.