[Noah]

I have a Sony VPH-1031Q CRT projector on the way, which is definitely a low output projector at only 500 lumens. Luckily it is virtually new so it should be at peak light output when I get it. Due to various room construction/layout considerations the 1031 will be mounted at a height of about 4 feet and project about an 80" wide image. Due to the low light output and large screen size, I am forced to consider a high gain screen. Unfortunately, cost considerations prohibit me from getting a Draper M2500. My questions are as follows:


1. Do I need a high gain screen given the light output of 500 lumens and screen width of 80"?


2. If I do indeed need a high gain screen, how would I go about making one? I've read many of the threads in this forum that cover the framing/painting of blackout cloth and other materials, but these threads seem more concerned with finding the optimum screen for high output projectors. Basically I'm wondering what paint or combination of paints/primer/gesso will produce the best screen surface for my application. My very uneducated guess is that I would need a high gain screen, but that may or may not be the case.


Any advice or suggestions would be greatly appreciated,


Noah

 

[wireburn]

Noah-


What's your budget? You can get a 80"x60" Dalite Model B (manual pulldown) with the High Power material (2.8 gain, highly recommended) for $225 shipped. Email me if you'd like the link.


-Mike

 

[snaggs]

As posted before, you can calculate how bright your screen/projector combination will be as follows;


80" Screen in 4:3 ratio gives


5.3'x4.0' = 21.2 square feet


Divide your ANSI Lumens (not peak), which for your model would be 150 I would guess.


150/21.2 = 7 ft lamberts


This is the brightness of your screen if it was 1.0 gain. If you used a higher gain screen, say the 2.8 high power, you multiply;


7 * 2.8 = 19.6 ft lamberts


Anything less than 9 is too dim, you really want 10-13. If have a bit higher, then you wont have to run your projector as hard. So a 1.5 gain screen is really the minimum you can go with something like a 2.0 gain probably ideal. Another option if your good with woodwork is to build yourself a curved screen. I dont know how to calculate exactly how much gain youll get, but figure around 1.5-2.0 if you were using a 1.0 gain material.


Daniel.

 

[Noah]

Thanks for the responses, guys.


Mike,


Unfortunately my college-student budget dictates my choice of screens. Since I just blew that budget on the projector, it really appeals to me more to spend $50 on a DIY screen as opposed to $225 on a Dalite. It also appeals to my personal philosophy to have a hand in the creation of my home theater rather than just assembling the pieces.


Daniel,


Thanks for the useful equations. Based on those the minimum gain I'll need is around 1.5, but I'd prefer 2.0-2.5 to save a bit of life on the CRTs.


Basically, I'm wondering how, using a combination of paints and fabrics, I can create a screen with that level of gain. I've considered using an undercoating of silver paint followed by a coat of the Sherwin-Williams Luminous white mentioned in this thread . Would this produce a higher gain, or will paint never approach the gain level of a glass beaded surface found in the Draper and Dalite high-gain screens?


Thanks again,


Noah

 

[KBK]

It's a long story, but it is unlikely that paint will ever equal the effect of glass bead. The effect that allows glass bead to work is partially associated with the distance you view it from, and the distance between the rod/cones in your eyeballs. It comes down to uniformity of characteristic, and application of specific characteristics.


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---Place Signature Here---

 

[Noah]

KBK,


I've found a few sources of glass beads and glass bead paint mediums:

Rolco glass beads

Liquitex glass bead medium


I'm going to the local art supply store later today to check out the paint medium and I may order some of the pure beads for a test screen. Will either of these be able to approximate the effect of commercially produced glass beaded screens? I'm planning to paint a few coats of Sherwin Williams Luminous White on a primed canvas and then apply either the paint medium (maybe thinned out slightly) or the glass beads. I think the glass beads might stick to wet paint, maybe with the help of a matte adhesive or lacquer. Any ideas on which of these products would serve my needs for a high gain screen? Is there a better way to utilize these products or do I have the right idea?


Thanks,


Noah

 

[KBK]

Been there, done that, very messy, poor if not unuseable results. Save your money. If your curiosity is as high as mine and are as stubborn to boot, you will of course, completely dismiss such warnings until you have acertained results for yourself.


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---Place Signature Here---

 

[Noah]

Quote:

If your curiosity is as high as mine and are as stubborn to boot, you will of course, completely dismiss such warnings until you have acertained results for yourself.

Heh, yes I may just have to do that. I trust your experience but I find myself pondering just how it would work...


Anyway, I am left wondering what exactly will produce a high gain screen besides a $250 'donation' to Dalite. I had thought that glass beads were the way to go, since that seems to be the material of choice for commerical screen manufacturers, but when I sit down and think about it I belive that there would be severe problems with uniformity in manually applying glass beads to a painted surface. Then I read a little post in the "POLL: Who's Using High Gain?" thread:

Quote:

Whatever I want.

I admit, I'm jealous. I would like to be able to produce a screen of whatever gain I wanted. I went back through the screen forum archives and re-read a few threads pertaining to DIY screens. I've come to a few conclusions based on previous threads. Based on what I've read I believe that I can come up with a reasonably high gain screen (about 1.5) using the following method:

Quote:

Originally posted by KBK: This is what I have come up with. First the sheetrock is coated with a latex primer. pure white, of course. Then a layer of pure white latex paint to finish the initial base. Flat or gloss, your choice. The next layer consists of this Gesso that I have been using. It is the premium grade gesso from this company I have been working with. The average brand of gesso you see at an artist's supply shop has approximately 1/4 the white (chalk) pigment of the stuff I am using. This stuff is in a gel form... It just will not carry any more pigment. The wall is coated twice with a a layer of this stuff in a thinned format. Absolutely matte, and the purest white availible. (not an egaggerated 'whiter than white') Then the next two to three layers are an adjusted layering of four different ingredients. This is the actual screen paint itself.

And then...

Quote:

Originally posted by KBK: Buy a pint of the Ralph Lauren design studio white. put half of it ito a mixing container. Buy some pre-thinned (ready to use)gesso from an arist shop. About 500ml should do. Toss it into the ralph lauren mix. Make shure you have purchased MATTE GESSO... This will calm down the gloss characteristic of the Ralph Lauren paint. It may be avilible in somethig other than the semi-gloss that I saw. Before you do all that, find a GLIDDEN paint store. They sell the PEARLESENT mix in a powder form so you can add it to any paint.

So, here's my summary:


latex primer => pure white latex (flat or gloss) => high-grade matte gesso => two or three layers of pure matte white paint/gesso/pearlescent powder mixture


I don't have the cash to buy a commercial screen, nor do I have time to wait for KBK's DIY kit with a projector coming on monday. So I'll do the best that I can with the knowledged gleaned from previous posts and my own uninformed guesswork. Again, I appreciate any advice from those more experienced than I.


Noah

 

[KBK]

I must say, it took years of learning how to teach myself how to learn, just to get to the point where I could come to valid enough conclusions, to only commit to a year of hard experimentation of trying to find out how screens work. Expect a minimum of 10 iterations of mid size examples, and 3-5 tries of full sixe examples. Expect about a minimum of $150 of costs, if you come to the correct conclusions at the right times, and make the right choices. Have fun.


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---Place Signature Here---

 

[Noah]

KBK,


Any chance of getting some advice here? I do appreciate all the months of work, dozens of iterations of paint mixes and combinations of layers, the reflectivity readings, etc. I'm sure it was more effort than I can possibly imagine and its probably going to change the entire market of front projection screens. But when it comes right down to it, some real suggestions from someone like you who has become a self-taught screen expert would be helpful to someone like me who needs a screen. So I'm going to come right out and ask it:

How do I make a high gain screen for a low output CRT projector?


I understand your desire to protect whatever formulas you've come up with and glean some profit from all your work, but given that limitation, what can you tell me? From your past responses I can see that you don't want to divulge this information. I this find very frustrating. I can't buy the kit and I can't do it myself without a serious investment of time and effort. Personally, I think the noble thing to do is to release whatever disoveries you've come up with. While this may not be the most profitable route it will result in a superior end product. Once your information is out there, there will be hundreds of "beta testers" who can report their findings with different paints, projectors, ambient light levels, and many other variables. I personally have found that there are a number of highly technical members of this forum who have a great desire to advance the science of home theater, many of whom have strong interest in developing better screens. The end result will be an even better product than you could've come up with on your own. Maybe that is not your goal here, maybe you'd rather make a few bucks than make the best screen. I hope that is not the case. I hope your are more of an enthusiast than a capitalist.


Noah

 

[kelliot]

I have tried it on canvas with a roller and couldn't get it uniform enough, but if you can spray Ralph Lauren Candelite Silver uniformly on white vinyl without problems, it might do the trick.


The ideal seems to look like duct tape with the texture of matte vinyl, IMO.


------------------

Ken Elliott

 

[MrWigggles]

Noah,


I've used Behr ultra-pure white (it is as white as a sheet of paper) in two gloss levels, flat and eggshell. The eggshell adds just a touch of gain without any hotspotting. I could easilly gone up to a higher gloss level I believe without any adverse side effects.


Steps I took. All Items were purchased at Home Depot.


Materials:


1. 4' X 8' sheet of white tile board. The white side of the tile board is a little too glossy but makes a great surface to start with. Have the attendant cut 10" off on side and you'll have a good sized 16:9 screen. Or have the guy cut whatever dimensions you want. Save the scraps they will be used for testing the gloss-level of paints you wish to use.


2. 1 quart of latex primer. Ask the sales person for the best one.


3. 1 bottle of flowtrol, a paint additive desinged to get paint to flow more evenly.


4. 1 quart of Behr ultrapure white eggshell or higher gloss level. I did an in-store test with several other "white" paints. The Behr was much brighter than the others; it is as white as it gets. Try various gloss levels if you want they're only $8 a piece. (BTW, what's the use of a 1.3 gain screen if it isn't pure white to begin with).


5. Rollers with very thin felt like covers. This will help ensure that the paint is put on smoothly. Also buy plenty of these. i.e. Don't try and reuse the one from the primer paint for the top coat.


Painting steps:


1. Using the scraps, try to get your technique and choice of gloss level finalized. Do half-and-half comparisons. With a scrap piece, I did one half completely flat and the other half with eggshell. The eggshell was slightly brighter, but had no hot-spotting so I went with it for my final screen.


2. Set-up your painting area. This might sound like a silly step. But to get an even coat, plan to paint well past the board surface. Use a nice big drop cloth or whatever it takes. I would also plan to stand above the board with the board laying flat on the ground. Then use a roller on a long handle paint while looking down.


3. Apply the latex primer. Getting a perfect coat here isn't crucial, but this is a good time to perfect your stroke with the roller.


4. Mix the Behr with the flowtrol in about a 6:1 ratio.


5. Start painting. Make sure not to start and/or stop anywhere on the surface. Only start or stop off the surface on the drop cloth or newspaper. Plan to do about 4+ coats. The thinner and more even you make the coats the smoother the final product will be.


6. If you screw-up or don't like the gloss level, you can always start over on the other side.


When you do get your final product, I think you will be able to achieve close to a 1.5 or so gain with a completely white (cleanable) surface.

Also this tile board material can be bent slightly if necessary. That will further reduce the chance of hot-spotting. There are limitations to these techniques, if you want something above 2.0 your proabably going to have to buy a professional screen.


Good luck, If you need more info please let me know.


BTW, You need to sign an NDA before reading this post. Also, my lawyers will be over at your house to distribute a licensing agreement whenever you elect to follow this patent-pending process.


-Mr. Wigggles


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The Mothership is now boarding.

 

[Noah]

Brett,


You have put together a good defense of our friend KBK (who curiously seems to be ignoring this topic since my 10-15 post) but if you don't mind I will stick to my opinion.

Quote:

I'm no moderator, and actually I'm usually pretty far from moderate! http://www.avsforum.com/ubb/wink.gif

I don't mean to start a flame war. There's no need to call in a moderator. My original intent of this thread was to ask those more knowledgeable than I how I might go about making a high gain screen. We have in our midst a character by the name of KBK, aka Ken Hotte, who has on several occasions proclaimed his ability to produce such a screen with a mysterious combination of paints and pigments. I had merely hoped to learn from his and other forum members' expertise in this matter. Now, he has every right to refuse to divulge any "trade secrets," of this there is no doubt. However, let it be known that when called upon to help a fellow home theater enthusiast, he would rather ignore such requests and promote his wonderful paint in the CRT forum under the guise of determining the perfect gain for CRT screens:

http://www.avsforum.com/ubb/Forum2/HTML/004169.html


This KBK is no home theater enthusiast, he is a home theater capitalist.

Quote:

...having done alot of tweaking and experimenting over the years I've become painfully aware of the high cost of such undertakings both in time and in expeditures.

I do not doubt that his experimentation has been fairly costly. In my quest for 'gain increasing additives' and high-grade acrylics I have come to understand this. I invite you to re-read my 10-15 post in this same thread. I am of the opinion that sharing development information in a highly technical group of people who seek the same goal will result in a superior end product than a product developed by a single person. In our case not only would this increase the quality of the end product, but it allows the cost to be distributed as well. If KBK's initial ingredients and techniques were known to us, then each one of us could test certain variables and report their findings back to the group. Lower cost, better product, both good things.

Quote:

He is very imaginative, good at problem-finding, analytical and perseverant. He is also willing to often reconsider his initial premises upon experimental interaction. The fruit of the progress he has made should become available to us in due time. After all he's pretty busy making all of our mistakes for us (even purposely ruining screens) so that we can get the best "without the mess". And his developments are pretty much unmatched out there.

I have no doubt of his skills and I believe his screens will be among the best. If they are half of what he has touted them to be, he will have something of value on his hands. The fruit of his progress may be available in due time, at a cost. The fact remains that he has repeatedly broken forum rules in his self-promotion. As to his experimentation, I'm sure many forum readers would rather participate in this process rather than pay for the end result. One of the things I like most about this forum is that we are a hands-on, do-it-yourself crowd. We'll deal with them mess if its worth it.

Quote:

I encourage you to undertake your own set of experiments. They will give you and possibly other forum members other alternatives for designing their own custom screens.

I plan to. I also plan to share in minute detail every step of the process, every single product used, and the results of my experimentation. That is the only way develop something as complex as a screen. I would not have even attempted such an undertaking had I not been able to learn from the experience contained in this forum and I intend to add to that my own experiences. I want the best screen for the money, I don't want money for the best screen.

Quote:

I personally do not yet have a can of that magical "KBK goop" but am willing to give him time to do things right, even if that means settling for my own home brew of white acrylic/artist titanium white and gesso paint mix (courtesy of KBK's considerate advice).

I encourage you and all other members of this forum who are content to wait for some thus far imaginary product to do your own experimentation. I'm not going to wait, I'm going to take action.

Quote:

Even if there was a profit motive there, KBK doesn't have any more obligation to dismiss profit issues than other forum members. You could more understandibly channel such discontent where it is more justifid, for example at others that to my knowledge have contributed far less than KBK to our modest understanding of screen reflection issues and who have a declared unmitigated profit motive: http://www.avsforum.com/ubb/Forum14/HTML/000784.html If by chance you could convince Mr Stewart to further our understanding of screen technology, it would be an "industry first"! http://www.avsforum.com/ubb/biggrin.gif Try to be gentle, as he is a "guest".

I would put Mr. Stewart in a different category than Mr. Hotte. He is not selling his screens through this forum, at least I have not seen any Don Stewart posts with a self-promotional tone to them but I promise you when and if I do I will ***** just as loudly. I will indeed ask him to enlighten the DIY screeners with his expertise.

Quote:

We are all hungry for useful information so lets not let our appetites drive us to cook the chef. http://www.avsforum.com/ubb/wink.gif

I am hungry for useful information, yes, but I am going to determine that information through a combination of my own experimentation and the knowledge obtained from this forum. No longer will I seek the advice of one Ken Hotte, but I welcome his comments and anyone else's as always. I will collaborate and share everything. No one is left out, nothing is sold, everyone can help.


We will all have better screens.


Noah


[This message has been edited by Noah (edited 10-19-2000).]


[This message has been edited by Noah (edited 10-19-2000).]

 

[Brett]

Noah,


Enjoyed reading your reply. I understand that it is a strictly personal choice on my behalf to want to encourage burgeoning entrepreneurship among members here seeking more than a financial opportunity, a new orientation to their livelihood (ie occupational fulfillment versus raw cash gains).


One problem with the development of know-how is that it is for the greatest part dependent on previous innovation, through established concepts and theories and indirectly through the educational and cultural influences that spur us to innovate ouselves in certain ways. This is why the entire issue of intellectual property and industrial protection is a critical debate for postindustrial society. Got a section of a forthcoming book dealing with this topic - so you are preaching to the converted. http://www.avsforum.com/ubb/wink.gif


It is true that progess is at least delayed by the retention of information or the protection of proprietory processes and technologies. However, there is alot of unethical misappropriation of others' know-how going on out there, with well known stories dating back to Edison's days if not earlier. It is only natural to protect your child, or your "brainchild". It is a pitiful irony to contribute to enrich those whose pilfering has wronged you.


So although I must agree with you on principle as far as the hindering of progress by information retention and proprietary rights, what is at issue is the interactive relationship between individuals and the community throughout the creative process. The liberty one may take with one's discoveries may may depend upon the extent of one's investment (would you "give away" your life's work in a forum?). Whilst a greater distance placed between oneself and the creative process may stem either from self-denial and altruism or from circumstancial facilities (ie teleological achievement) which can grant a loftier attitude towards creative projects.


I'm only too glad that there are those such as you and Ken in this forum with greater momentum, time and intellectual availability to undertake this task in my stead. I relish the thought of the advances that will be made in this "mission critical" final step before the light meets the eyes.


Happy screen-making!


------------------


Brett


[This message has been edited by Brett (edited 10-19-2000).]

 

[Noah]

Quote:

BTW, You need to sign an NDA before reading this post. Also, my lawyers will be over at your house to distribute a licensing agreement whenever you elect to follow this patent-pending process.

Hah, you and KBK can sic your patent lawyers on me, I'm always ready for a good fight!


But seriously, thanks for the info, Mr. Elliot and Mr. Wigggles. I'm glad some members are interested in sharing and collaborating rather than using this forum to self-promote some non-existent product (AHEM, KBK) and ignoring direct requests for help. You can just keep your secret little paint formula up in "The Wilds Of Canada" as far as I'm concerned, KBK.


OK, I'm almost ready to paint. I've obtained a product made by Liquitex called "Iridescent/Pearlescent Medium" that can be added to paint to produce a pearlescent effect (as the name implies). I'm planning to add this either to the Sherwin-Williams Luminous White or to the Behr that Mr. Wigggles recommends (there's some disagreement as to which one is whiter) along with some matte gesso and use this mixture as my final layer. Any suggestions? I think I have some idea of what to do now...


Thanks again,


Noah

 

[Brett]



Hi Noah,


I'm no moderator, and actually I'm usually pretty far from moderate! http://www.avsforum.com/ubb/wink.gif


I do understand your point of view as it was my initial impulse in the same set of circumstances. However, having done alot of tweaking and experimenting over the years I've become painfully aware of the high cost of such undertakings both in time and in expeditures.


I also came to the realisation that KBK is far from motivated by greed (although he may jest about it at times) but mostly wants to try to at least partially recover some of his costs in manhours and cash to enable his continued further pursuit of the ultimate Home Theater experience.


He is very imaginative, good at problem-finding, analytical and perseverant. He is also willing to often reconsider his initial premises upon experimental interaction. The fruit of the progress he has made should become available to us in due time. After all he's pretty busy making all of our mistakes for us (even purposely ruining screens) so that we can get the best "without the mess". And his developments are pretty much unmatched out there.


I encourage you to undertake your own set of experiments. They will give you and possibly other forum members other alternatives for designing their own custom screens.


I personally do not yet have a can of that magical "KBK goop" but am willing to give him time to do things right, even if that means settling for my own home brew of white acrylic/artist titanium white and gesso paint mix (courtesy of KBK's considerate advice).


Even if there was a profit motive there, KBK doesn't have any more obligation to dismiss profit issues than other forum members. You could more understandibly channel such discontent where it is more justifid, for example at others that to my knowledge have contributed far less than KBK to our modest understanding of screen reflection issues and who have a declared unmitigated profit motive: http://www.avsforum.com/ubb/Forum14/HTML/000784.html


If by chance you could convince Mr Stewart to further our understanding of screen technology, it would be an "industry first"! http://www.avsforum.com/ubb/biggrin.gif Try to be gentle, as he is a "guest".


We are all hungry for useful information so lets not let our appetites drive us to cook the chef. http://www.avsforum.com/ubb/wink.gif


------------------


Brett

 

[Figgie]

I have a question? Has anyone tried applying the pearlecent/glass bead paint with an Automotive spray paint gun (HVLP type?). They do a good job on cars why not here???


------------------

Due to recent financial contraits.. the light at the end of the tunnel will be turned off until further notice... thank you.


The Management

 

[KBK]

The sprayers will not handle any pariculate of such nature,and will be destroyed in the process (tip wise). The breathing apparatus puts you in the commerical restraint category, with full warnings, dangers, lung damage, and disclaimers. As well, it won't work. So, try if you must... but be sure to cover everything, and get ready to buy new sprayer components, suffer flow problems at the least,and take extreme care with eye protection and breathing apparatus. Particles about 10 times smaller than the glass bead are not to be used with a spray system, so....


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goosystems.com


Ken Hotte

[email protected]

[email protected]

 

[jcmccorm]



Up above on this thread Mr Wiggles mentioned using TileBoard for the screen. This stuff is easy to find, smooth, wrinkle-free, and I don't have to stretch it over a frame (although I'd still build a frame for it). Has anyone else had success with this?? Are you still happy with yours Mr Wiggles?? Thanks...


Cary

 

[Figgie]

well let say that you had the booth? How do they apply the pearlescent under coat before applying the "candy" color over it. It has to be a automotive type gun Of course not HVLP but some other type of gun? Maybe the basic Air spray paint gun that also does the metallics?


------------------

Due to recent financial CONSTRAITS.. the light at the end of the tunnel will be turned off until further notice... thank you.


The Management