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Discussion Starter · #1 ·
Hello to all the brilliant folks here doing research on methods that are admittedly not in my field of expertise...my head's swimming after an entire evening of searching, then registering, then more searching and reading. I found a lot of information, but not specifically to what I'm looking for, or at least not in language my simple brain can grasp...:help:

I'm putting together my passive linear stereoscopic 3D home theater system and I want to build the screen to my own dimensions and specifications. There are a couple (I think literally 2) companies that make a silver paint that can be sprayed onto your screen surface and you could call it done. I am, however, looking for a more DIY solution that doesn't require purchasing 1000ml of paint for $200-$400. I've read all over the place, several people stated they've used silver paint and successfully had their system up and working fine, however none of those people posted a single usable detail about what type or mixture they used.

I have all my equipment, filters and supplies, I just need to figure out the screen part. I've looked at Screen Goo's "Ultra Silver 3D" product as well as the Paint on Screen "3DHD Silver Screen" paint, though as stated, I'm looking for something more creative and DIY.

2 x Panasonic PT-D3500u commercial projectors with filters are being used, so there's plenty of lumen count to push any type of paint, I'm assuming. I had a demo on the system and it is absolutely beautiful, I just need to get the screen figured out so it can be doing it's beautiful dance for...me. :flex:

Sorry if this is a covered topic. I searched and, as I said, found a lot of information that "pointed" towards different things, but hopefully I'm not the only one looking for stereoscopic options and possibly can pull info about it specifically to a point here. Thank you for taking the time to read and I'm looking forward to any help!

:T
Thanks!

Sean
 

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I have to admit Sean that I'm a bit behind on the 3D side of things but why would you need a silver screen for 3D? Are all of the big theaters changing out their screens for silver screens? Is it gain that you're looking for?

I know that the Silver Matte material from Da-Lite was for 3D Polarization. I liked that material too. :scratch:

I'm gonna have to do some research into all of this 3d stuff. The only latex silver paint that we know of outside of Auto Air Aluminum would be BlackJack 5168. If you're lucky a Walmart near you stocks it and sells it. Outside of that there are the spray paints and oil based paints. But you wouldn't want to use those in your house.

This may be another application for the Brilliant Metallics at Lowes.
 

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Hi Sean,

I assume you need a screen that retains polarization of the reflected light. This can be a problem with DIY screen mixes, but not an insurmountable problem.

I was involved in another thread on another forum where a person had a similar need to your own (if I understand your need correctly) and he discovered that NONE of the screen paints using mica (most of the mixes recommended on that forum) as the reflective agent worked at all, and that it didn't take the addition of much latex paint to depolarize mixes using aluminum as the reflective agent (most of the mixes recommended on this forum). His final answer was to use straight aluminum paint and then coat it with a clear medium to lessen the hot spotting such a metallic paint will have. He used a Behr product called Faux Glaze, but the indications are that most any flat or matte clear medium would work. The problem with using a clear top-coat of this kind is that most of them will discolor over time (usually turn yellowish).

To retain polarization you need to have a truly metallic paint. Many so-called metallic paints really contain mica flakes and these won't work.

The aluminum paint we use in our Black Widow™ screen mix would work, but it is around $200 a gallon. Sherwin-Williams has a water-based aluminum paint called Bond-Plex that is around $90 a gallon, but it must be special ordered at the S-W stores in my area. Your best bet could be the Black Jack #5168 Aluminum paint that some Wal-Mart stores sell, it is way less expensive than the other options listed above.

No matter what aluminum paint you use you will almost certainly have to spray it on your screen, rolling simply leaves too many visible imperfections.

You will have to coat any of these paints with a flat/matte clear medium to control hot spotting. I really can't recommend one over another since I haven't tried them for this purpose.

I wouldn't advise paying big bucks for "special" 3D paint.

This is definitely an area we need to do more research in.
 

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Harp I think you can save me some searching, hopefully.

What exactly does the metallic do that would retain or enhance the polarization? How would it be lost on plain old regular paint? I don't understand why polarization would be lost with regular paint. :scratch: For some reason I keep thinking that it's a gain thing. :dontknow:

I read up on it some and everyone seems to think you need these silver type screens. But I haven't seen why. :scratch:
 

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I don't know why the true aluminum paints maintain (it does not enhance) the most polarity in reflected light, but I suspect it has to do with them not overly diffusing the light, as a flat paint would do, nor refracting the light which mica paints would do.

I really need to get some new polarizing filters (I misplaced my old ones).
 

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I don't know why the true aluminum paints maintain (it does not enhance) the most polarity in reflected light, but I suspect it has to do with them not overly diffusing the light, as a flat paint would do, nor refracting the light which mica paints would do.

I really need to get some new polarizing filters (I misplaced my old ones).
That does make sense. And is suppose if it diffuses it too much then it may seem a bit dimmer. This may be a good thing for the mylar with a thin sprayed coating of some sort. :scratchchin:

How big of a screen are we talking Sean? Do you have any hydroponic stores nearby?
 

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Discussion Starter · #7 ·
Hi Sean,

I assume you need a screen that retains polarization of the reflected light. This can be a problem with DIY screen mixes, but not an insurmountable problem.

I was involved in another thread on another forum where a person had a similar need to your own (if I understand your need correctly) and he discovered that NONE of the screen paints using mica (most of the mixes recommended on that forum) as the reflective agent worked at all, and that it didn't take the addition of much latex paint to depolarize mixes using aluminum as the reflective agent (most of the mixes recommended on this forum). His final answer was to use straight aluminum paint and then coat it with a clear medium to lessen the hot spotting such a metallic paint will have. He used a Behr product called Faux Glaze, but the indications are that most any flat or matte clear medium would work. The problem with using a clear top-coat of this kind is that most of them will discolor over time (usually turn yellowish).

To retain polarization you need to have a truly metallic paint. Many so-called metallic paints really contain mica flakes and these won't work.

The aluminum paint we use in our Black Widow™ screen mix would work, but it is around $200 a gallon. Sherwin-Williams has a water-based aluminum paint called Bond-Plex that is around $90 a gallon, but it must be special ordered at the S-W stores in my area. Your best bet could be the Black Jack #5168 Aluminum paint that some Wal-Mart stores sell, it is way less expensive than the other options listed above.

No matter what aluminum paint you use you will almost certainly have to spray it on your screen, rolling simply leaves too many visible imperfections.

You will have to coat any of these paints with a flat/matte clear medium to control hot spotting. I really can't recommend one over another since I haven't tried them for this purpose.

I wouldn't advise paying big bucks for "special" 3D paint.

This is definitely an area we need to do more research in.
Thank you for the helping hand Mech, Harp!

Indeed, all correct here Harp, the image needs to have it's polarization retained after the filters in front of the lenses so that the polarized glasses you use can pick up the correct image from each projector. Mica does indeed diffuse the light far too much, or too well I suppose, and loses the polarization needed. Since we're not talking about the ugly anaglyph method of 3D that most people equate with stereo projection that you get when you use the red/blue lenses, mica is impossible to have anywhere on your wall from what I've read. Aluminum paint offers the only hope, and I'm assuming that's the reason why these two companies offering 3D screen paint are so pricey.

I purposefully got a commercial setup because these projectors both offer 1080/60i and 3500 lumens to be able to still push a brilliant picture despite the silver needed. I live in SoCal so, I would assume there are a plethora of hydroponic sources locally.

I've read some of those posts, though I'm not sure if it was yours or not that was the advise, suggesting no matter what the end paint, or in one case, silver cloth, it will probably need a coat of satin or eggshell clear over top to eliminate the hotspotting of the high lumen count.

The dimensions are probably going to land somewhere in the 144"-156" range total, as I'm attempting to recreate an IMAX like experience for not only movies, but also 3D model development and presentation, and the occasional 3D game for the kids. This of course being optimal sizing and subject to change as info and research require.
 

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At your maximum stated screen size PJC's calculator is saying you are getting from 18-21 fL. in video mode depending on PJ zoom setting. The aluminum paints I have measured with my spectro has all been around a N6 in shade, but of course they would look much brighter than that due to their specular reflective nature. Without some way of diffusing such a screen I would expect it to hot spot quite badly and have a very narrow viewing angle, if it was watchable at all.

My concern about using a true mirror-like surface like aluminized mylar is that when enough clear diffusion coating is applied to reduce hot spotting to a tolerable level it will extinguish much of the polarization. There is nothing to do but to try it and see.

I will try to get some BJ #5168 (it might not even be available to me) and some polarizing sheets.

I'm leery of the commercial 3D screen mixes you mentioned in your first post. I was sent some of Goo's Ultra Silver to test, but health problems prevented me from testing it in a timely manner. It will be one of the mixes I test when I get back to spraying panels. While I'm not saying it won't work for 3D projection, it does contain some kind of material that breaks white light up into colors (it looks very much like mica, but it may not be). :dontknow:

I haven't seen any of the paintonscreen 3DHD Silver Screen paint, but the specs they list defy the physics of reflection, at least as I understand them. They say this paint has a gain of 4.0 or higher yet they still claim a viewing angle of 110°. Something isn't right there.

Looking forward to reading more of how you go about building this 3D screen and we will be glad to help where we can. :T
 

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Discussion Starter · #9 ·
I read through the black widow thread, or at least what I could comprehend as the meat of it. If I were looking into using the blackjack to come up with a blend that would at least get going in the right direction, what should I be mixing in and what ratio's would you recommend as a starting point to test out with them?

Also, I noticed that during the demo I took for the equipment, the screen was actually tilted down and it didn't make a difference in the 3D effect as far as I could tell. Would a tilt in the screen in combination with a clear overlay have any effect on reducing the hotspotting?
 

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I read through the black widow thread, or at least what I could comprehend as the meat of it. If I were looking into using the blackjack to come up with a blend that would at least get going in the right direction, what should I be mixing in and what ratio's would you recommend as a starting point to test out with them?
This is all theoretical on my end at this point. After you get some Black Jack to experiment with I think I would try painting something like posterboard (or primed hardboard if you have the tools to cut it) with the BJ and then try coating that with various types of clears and check what effect they have on polarization. I would try Behr Faux Glaze and also some untinted Deep Base (a type of paint used to make very dark colors - 8 fl. oz. samplers are available at Home Depot) in flat, eggshell and perhaps satin (but I think satin will probably be too shiny). There is also a chance that actually mixing the clear medium with the aluminum paint might work as well.

Also, I noticed that during the demo I took for the equipment, the screen was actually tilted down and it didn't make a difference in the 3D effect as far as I could tell. Would a tilt in the screen in combination with a clear overlay have any effect on reducing the hotspotting?
Yes, that makes perfect sense to me. By tilting the screen forward at the top you are effectively increasing the angle of incidence of the PJ beam at the screen (same as raising the PJ higher); this would drop any visible hot spotting from normal viewing height onto the floor, or at least to below eye level. Keep in mind that this will not actually stop the screen from hot spotting, it will only make it so the viewer will not see the hot spot; you will still be losing image brightness due to the hot spotting. This may or may not matter.

The clear top-coat will help prevent hot spotting; tilting the screen will only help prevent seeing the hot spotting. The former is better, but might lose polarization while the latter will not.

If I have failed to explain something well enough or if you have any questions at all please don't hesitate to ask for clarification. :T
 

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Discussion Starter · #11 ·
Well, between the great info here and the other threads I've read over and over, I'm going to do some experimenting and maybe post notes and get feedback as i go since hopefully I'm not the only one here who's going to be doing a similar setup. Unfortunately, two roadblocks are in front of me and the direction I'm wanting to go in order to start experimenting. Firstly, I live in SoCal and there are 4 counties (ours being one) that recently tightened up the VOC level requirements, which knocked virtually all the BJ products off the shelves in the entire surrounding areas. Secondly, I'm having a hard time confirming that Gardner-Gibson even still makes the #5168 any longer. I've got an email into them and I'll post up the reply when I receive it back.

My plan is going to be to get some posterboard testing going, only visual since I have no equipment or know-how on reading spectral data. It's going to be strictly visual and whether or not the polarization is preserved with different variants. I'm going to play with the recipes for the variants of the black widow, using the aluminum paint instead of the additive since, I want to find a lower cost solution for other people doing the same thing.

I'm searching now for a substitute other than the AAA as for an aluminum paint to use. I just got off the phone with a rep from Gardner-Gibson who said that the only product they sell in CA, Black Jack silver seal 500 isn't the same type product as the 5168, leaving me out in the cold on being able to get some unless I have it shipped from out of state:hissyfit:

Ace hardware said they have an aluminum paint that they sell that doesn't contain mica, I'm going to head over there when I get some time to see if it might be usable or not. Any other recommendations?
 

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I can't think of any other water-based aluminum paint other than what I have already suggested that is any cheaper than the AAA-F.

Something else you could try is a paint called Craft Smart Metallic Silver that is sold by the Michael's art&craft stores (it is their "house brand" of craft paints). I don't know what the reflective agent is in this paint, but it's not mica. I'm theorizing this it is some form of aluminized polyester or mylar. The guy in the thread I mentioned said he tried some of this and while it did work to a point it didn't retain as much polarization as the paints containing true solid aluminum flakes.
 

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Discussion Starter · #13 ·
I'm going this afternoon to pick up a quart of different aluminum paints from lowe's and ace, provided that they are mica free. I'll get some poster board and hopefully do some mixing and testing over the next week or so. though I'll be posting shortly after I've got the 2 samples along with supply of the 427-2 to mix in at different ratios and hopefully something magical comes out the other end.:T
 

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Well, between the great info here and the other threads I've read over and over, I'm going to do some experimenting and maybe post notes and get feedback as i go since hopefully I'm not the only one here who's going to be doing a similar setup. Unfortunately, two roadblocks are in front of me and the direction I'm wanting to go in order to start experimenting. Firstly, I live in SoCal and there are 4 counties (ours being one) that recently tightened up the VOC level requirements, which knocked virtually all the BJ products off the shelves in the entire surrounding areas. Secondly, I'm having a hard time confirming that Gardner-Gibson even still makes the #5168 any longer. I've got an email into them and I'll post up the reply when I receive it back.
According to Tiddler he did manage to talk to someone at Gardner-Gibson that told him it isn't discontinued. I am still trying to get a verbal confirmation. Still though, it isn't sold everywhere.

With that said I have around 25 gallons and I am sure I could see my way to sending you some ;)
 

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Discussion Starter · #15 ·
Well, you are indeed correct, I spoke with a rep from Gardner-Gibson who confirmed they still make it and that Wal-Mart is indeed their ONLY customer for the #5168. Unfortunately, the great state of CA's strict VOC limits have (as of about 6 months ago) effectively banned Black Jack from being sold in the state, so I can't get it anywhere. I called every wal-mart in a 250 mile radius over the past several days and nobody has it, and a general consensus that they won't be carrying it any more. While that may very well be the best option available in the range I'm planning for, it's not an option I have available to me. So, on to things I can actually get my hands on.

I went out and picked up a few different options and made a test board to test out after I got the projector setup somewhat tuned tonight. I used 4 variants, though to be fair, I messed up on the 4th and don't count it as a true representation and I might do that one over again since it was an interpretation of the BW mix with the BJ. I got 2 different kinds of spray, one was rust-oleum aluminum spray, the other was rust-oleum brilliant metallic flake silver. The paint I picked up was also made by rust-oleum and was a metallic aluminum paint. I picked up a tester can of bermuda beige as well to mix up, which I'll be doing over because water got into the mix and I didn't realize it until I'd already rolled over half the sample section.

The aluminum metallic spray was very dull and only a slight step above the messed up water infused BW mix that I'll be redoing. It was only mildly reflective and didn't hold vivid colors well, so this was nixed right out of the gate.

This left only 2 "real" comparison samples unfortunately until/unless I come up with others over the coming weeks. The other spray was the brilliant metallic flake silver, and it went on very evenly and smooth with quite a lot of very smal flakes that did look good without a picture, and held up well when I projected on that section. This section retained the polarization nicely and I thought was possibly the best representation of detail out of any of the samples. It wasn't overly vivid, which surprised me, given the fine nature of the flakes in it and how evenly it sprayed. I'm actually going to give this section another coat or two tomorrow and see if that makes any difference. I really liked the depth of this option and just wished it was a little brighter.

The last and probably most surprising option was the plain rust-oleum metallic aluminum paint that was rolled on with no primer and no Bermuda beige. I was actually going to expect this to be far too reflective and just use it to show the other sample clarity. It actually turned out to be fairly sharp to my surprise. The color depth wasn't as good as the brilliant silver, but it was easily the most vivid of the 4. I'm not sure what difference spraying on BOC would make, but on poster board with one coat rolled, it looked nice and retained the polarization effect nicely as well. This is looking like a very nice option to play with and see what, or even if, a mixture needs to be made of it for my setup.

I wasn't able to find any spcific properties either on the can, or on the rust-oleum or lowe's website to say what the specific compound is, which I don't like too much. It does what I'm looking for, so that's a good step in the right direction. How much better are the higher end products or even other products in regard to what I'm attempting?
 

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Since you are doing this in SoCal I'm not sure of the paints you are using, but all the metallic Rust-Oleum spray paints (and most of the canned paints) I know of are petroleum-based. The options we have given you are all water-based. The two different bases will not mix together well at all.

You can get the MSDS/TDS data for Rust-Oleum paints here.

My understanding is that it won't take much opaque paint (such as the Bermuda Beige) to have a large negative impact on polarization retention. I think your best bet will be to try different metallic paints by themselves first and then perhaps clear overcoats to help dull them if they hot spot too much alone.
 

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I haven't keep up to date on this thread lately...

My thought process back where I left off was going to be the mylar with a couple of lightly sprayed frosting coats on top. Would that work Don? :scratch: Or does it work better to have aluminum/silver particles interspersed within the paint?

You'd need enough paint to knock down the mirror qualities of the mylar.
 

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I haven't keep up to date on this thread lately...

My thought process back where I left off was going to be the mylar with a couple of lightly sprayed frosting coats on top. Would that work Don? :scratch: Or does it work better to have aluminum/silver particles interspersed within the paint?

You'd need enough paint to knock down the mirror qualities of the mylar.
The aluminized mylar might work, but it would probably take a thicker top-coat to diffuse the hot spotting than if you used a sprayed aluminum paint. The paint is already at least semi-diffusive due to the billions of metallic flakes instead of a single flat layer as with the mylar. But I'm just guessing here. :dontknow:
 

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Sean,
I just came across your post, and maybe I can lend some helpful information if you haven't already found a solution.
The problem with a mirrored surface like aluminized mylar is its tremendous directivity which leads to hot spots out the ying-yang. I don't think you'll ever be able to control these with a coating without seriously degrading the polarization quality of the surface, as well as the image quality itself.
Try this approach: a metallic coating on an irregular surface. DaLite's silver screen takes this approach. They start with an imbossed base material and coat it with an aluminum type coating. The imbossed base affects directionality and drastically reduces hot spotting.

Recently, I've been working on a circular polarized 3D system which has the same screen requirements as a linear polarization system. I used nybco "Silver Touch" spray enamel in a test, which produced a surface with better polarization-maintaining quality than a DaLite silver screen sample. It had better reflection and better extinction of the opposite polarization rotation, but it had the potential for hot spotting (when sprayed on a flat surface) and shedding. I'm working on those two faults now, but I believe the solution to hot spotting is the base surface, and the implementation of an irregular texture of some sort (perhaps an old screen fabric of some type). A thin overcoat should remedy the shedding, but I will have to experiment to find something that doesn't interact with polarization. That could be a bit tricky since any plastic type material will significantly affect polarization.

Polarization is a physical quality of a surface, and is affected by the electrical conductivity of the material which in turn, affects electrical fields in light striking the surface. That's why a solid sheet of aluminum will preserve polarization and an identical "gray" surface using paint will not. Likewise for mica. The paint must contain metallic particles, and in most cases, aluminum is used to the best effect.

Keep in mind, any spray paint will usually result in airborn particles (vehicle and metallics) and vapor, both of which can be hazardous, so it's best to do any spraying in an area outside or where the particulates and vapor won't be a problem.

Give us an update on your efforts.

RD
 
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