New cheap DIY screen - Page 6

Just wanted to keep you updated.

After having watched all sorts of movies on my screen I'm still very happy with it.

Here are some things I enjoy most about my dark gray screen:
-No masking needed. 16:9, 4:3 or any other format just looks great. There's almost no difference noticable in the gray tones of the movieborders to the material not lighted up by the pj.

-Ambient light no problem. Even with the lamps on theres a very viewable image. No need for a bat cave. Dimmed lighting makes almost no difference to total darkness.

-It is 'cat safe'. As often as my cat has climbed the screen any pvc screen material would have been shredded. The claw marks in the spandex are gone within hours. (Trying my best to convince my cat not to climb the screen... )

Best regards!
Darker_plz

I was reading this topic on my phone so forgive me if this has been asked and answered and I missed it. As I don't have a projector yet, I can't do any testing of any kind yet. But I was wondering how two layers of white spandex might perform as an AT screen in a light controlled environment as well as possibly some ambient lighting situations. Again sorry if anyone already touched on this. Phone isn't the best for browsing.

Matt

Hi,

Having read all the previous discussions and looked into other options I have decided to build a custom acoustically transparent screen for my home theatre.

The room is a 12mx6m 100-year-old barn that I have restored. It's built on stone walls 0.5m thick. I have an Acer H-5360 projector installed on one of the three beams that hold the roof structure. The image projected is 189" x 107" in 16:9 mode.

Seymour's XD fabric is out of the question since it isn't wide enough and does not stretch but a meager 1%.

I have narrowed my choices down to Dazian Coated Celtic Cloth (CCC) and a combination of white Trapeze (be it standard or ES) and black Trapeze+ in a dual-layer combination as discussed in this forum.

1) Dual-layer spandex: Distances.

My first question is with regard to the distances to be allowed between the left, right and center speakers (Onkyo SKS HT540) located behind the screen.

I have gathered from this and other fora that a 4-6 inch distance should be allowed between the speakers and the screen. However, I haven't found any clear information on whether the black and white spandex should stand directly on top of each other. What should the distance be between the speakers and the back layer? How about the front white layer and the black back layer? As you can imagine these distances have implications in how I will be approaching the framing system.

2) Dual-layer spandex: Fabric choice.

Secondly, I have to choose two from the following fabrics:

1) White front layer:

Option A) White 2-way stretch, Trapeze in 120" width with a stretch ratio of 60% in width and 100% in length.

Option B) Alternatively, I could also use Trapeze ES. However, this material has a 40% x 70% stretch ratio which would not be enough for my purposes (I'll explain next).

Option C) White 2-way stretch, Trapeze + in 122" width with a stretch ratio of 50% in width and 90% in length.

2) Black back layer:

Black, 2-way stretch Trapeze + in 122" width with a stretch ratio of 50% x 90%.

3) Dual-layer spandex: Stretch ratios (independent and combined).

The question here is what stretch ratio would be ideal for each layer (both individually and while working together) and whether any benefits may be obtained from using another combination of fabrics different from the intuitively obvious choice of both black and white Trapeze +.

4) Dual-layer spandex: Backing.

Furthermore, given that the screen will be placed on top of a limestone stone-wall (pointed with a white cement and lime mix), should there be a need for a backing behind the dual-layer screen that cover the whole are behind the screen but the speakers?

5) Dual-layer spandex: Edge concealment and Amblone installation.

Lastly, give the different aspect ratios in different shows, movies, video-games, etc. how can be the building of the frame be approached taking into account the dual-layer construction? I'd like to be able to conceal any part of the screen that is not being used and, to further complicate matters, I'll be also installing an Amblone LED lighting system. Bear in mind that VLC allows to shift the image projected upwards to the extent that the upper border of the film will coincide with that of a regular 16:9 projection so that the area to be dealt with aesthetically can be confined to the bottom part of the screen.

6) Dual-layer spandex: 120Hz, HD 3D projection.

Finally, as a bonus question, what are the implications that such a screen would have on Nvidia 3dvision projections?

Thanks in advance for all the good advice you have provided already.

Regards

Lots to chew on....lots to digest and consider. Watch this space for a later reply. Church bells are beckoning.

Hi Mississippi man and everyone else.

Thank you MM for your prompt response. I have updated my post with hyperlinks and rearranged the questions/issues/topics hoping to further clarify matters and streamline responses.

I look forward to hearing from everyone and providing you with any further information you should need.

Regards

I live in a 100 yr old barn too...(...for the last 25 yrs...) but it's not able to allow me, of all people...to even have a Screen. So I take it out on everyone else by making them all do something I cannot.


That's OK because Seymour isn't a DIY material by they way we judge things on here.


Trapeze would be the better choice.


The closer the two layers are the better


It's all about getting the material to cover the Frame size desired, and doing so without excessive stretching. Obviously the less any spandex is stretched, the less porus the surface is because the weave stays tighter. The tighter (less stretched out) the reflective surface is, the better.

The background material can be anything, and needs not be completely stretched perfect like the projection surface.


Not if the 2nd layer does it's job. You'll never see anything behind it if such is the case.


By using a "Overlaid trim" method, one that also incorporates a 1" wide "Flat Inside" edge along the Bottom / Sides, you could make a Black velvet wrapped Frame that could attach via velcro fastners. To get the unbroken length you'd need, and also keep wieght to a minimum, I'd suggest using the 16' sticks of 3.25" MDF Trim that you'll also need to use for the rest of the Screen Trim. Another nifty idea. The Bottom edge could be "reversed, with any Taper of the Trim coming outward so you could slip the edge of the Wrapped masking panel behind it. and let the velcro handle the vertical sides.


For anything passive....fergittabowdit. For Active, at that size....you'd need a PJ with maximum lumens to offset the light lost to both the 3D presentation / Glasses, and the screen's degree of light absorption.

If 3D is desired, I would back the top layer with a Bright Silver Spandex....not a Black variety. I might suggest that as being a better route overall than Black as the silver will conserve light loss and also increase perceived contrast.

Chewin' the Cud works both directions. Get ta chompin'.

Hi everybody,

Thanks MM for all your input. My grandparents' barn was built in 1879 so it probably still beats yours by a couple decades! On the other hand, I write from Spain so 1912 is much more ancient in US terms than 1879 is here!

I'm glad to hear Seymour XD isn't considered DIY. I'm still puzzled at the physics behind those micro-holes and how they compare theoretically and pragmatically to a dual-weave pattern.

1) Trapeze over other Dazian fabrics.

Actually Trapeze was my initial option on account of its 60% stretchability width-wise.

Two questions:

1a) How about standard Trapeze (discontinued) vs. Trapeze ES? Standard Trapeze's stretch ratio is 60%W x 100%L, while Trapeze ES's is 40%W x 70%L. Trapeze is 90% polyester x 10% lycra while Trapeze ES is 94% and 6%.

1b) Since you have advised on previous posts that the white layer be stretched as little as possible what would be your recommended stretch ratio for Trapeze (white layer) and Trapeze+ (dark layer) and should it be matched length- and width-wise?

2) Dual-layer spandex: Distances.

I gather that 4-6 inches is the right distance to keep between the speakers and the screen. Similarly, I understood that both layers should be laid on top of one another so that they be in direct contact.

3) Dual-layer spandex: 3D.

Nvidia 3D is active so no problem there. If I understand correctly you are pointing out that black can be substituted for another color provided that the fabric reflects back as much light as possible. Given the colors available from Dazian, would Titanium be a better choice over black?

4) Dual-layer spandex: Framing.

Now that I know that both layers should supersede one another I can get to work on designing a framing system that suits my needs: Time to visit the scrapyard.

Regards and thanks again MM.

You might consider extruded aluminum for the frame, as it's light, rigid and won't warp as the humidity changes. The stretchable fabrics in my experience need 360 degree support around the frame to keep the fabric from bowing at the edges. I tried the spandex route which worked great for audio transparancy (two layers with black behind). I had the black behind directly up against the white.

For the frame, I used T-Track extruded aluminum from the company 80/20, from their metric line. I bought several 8' sticks, then cut them to piece together a 108" x 45" 2.40:1 frame, then I took to a metal fab shop where they heliarc welded it together on a large jig, to ensure they were perfectly square. I covered it in black velvet. The fabric is held on the frame by pressing 1/2" plastic tubing into the T-track to hold the fabric there. Worked perfectly with a strong hold (that is reversable), and gives 360 degree hold around the frame. If your interested in this technique, let me know and I'll put up pictures and a cross section diagram.

Regarding the spandex, the problem I had was when stretched, the weave of the fabric bunched up or spread apart unevenly, leaving visible patterns. During dark scenes it was no problem, but with bright scenes it was clearly visible. I ended up going with a fabric by Seymore AV, which I'm extremely happy with.

I'm going the 80/20 route, so any pictures you have would be mucho appreciated! I am also working on designing some rotating joints where the screen would mount to the ceiling - so instead of a roll up screen i end up with a fold up screen, ie just lift the bottom of screen to the ceiling and connect to another hook to hold it there. When I finish designing and start ordering/building parts, I'll probably post it all in a thread, but in the meantime any pics you have would be helpful (in a new thread is fine, so as not to hijack this one).

still undecided on screen material in terms of spandex vs a mfg material like seymour (ssshhhssh, don't tell people here ). I'll likely try the spandex route first, even if it turns out only to settle on a final screen size.
thanks!
rukus

bh, when you switched to the Seymore screen material, were you still able to attach it with the plastic tubing or was it too stiff? Also, was the part of the screen that was on top of the 80/20 tubing part of the viewing area or did you cover that with a mask/frame?

A picture is worth a thousand words, so here is 6K worth:

This first picture is a crossection of the frame that I used to illustrate the orientation of the material for the welder.


This next one is the actual material. It's quite large, and makes a perfect (in my opinion) frame for a movie screen. The outside T-Slot gives you many mounting options. The corners are 45 degree cuts as you would for a picture frame.


Next is a picture of the finished frame, mounted in place, but without the black velvet. To mount it I used two "living" hinges where one arm of each hing is attached via T-Slot on the top left and right of the frame, then the body of the hinge attached by large bolts to the framing structure above. This way the screen swings up from the bottom. Worked very slick. The hinges are machined from a solid block of aluminum and easily handle the weight.


The below picture is from the back side of the frame with the spandex installed. The tubing is hard to see because it's clear, but it's pressed into the inner T-Slot. To start, I strung a string accross the top of the frame and folded the cloth (both sheets together) over the string to hold it up (I used some tape as well). Then I started from the middle and worked my way out to the edges, stretching as I went. A nice side effect of this method is that if there is an uneven or drooping area, you can just pull firmly on the cloth and it will pull the tubing out enough to make adjustments in a small area.


Here another shot from behind at one corner with the fabric trimmed. You can see the white spandex here.


Here is a shot with the screen lifted up from the bottom, the fabric is fully installed. It took about 2 hours to finish.


If you want to replicate this I might suggest ordering the 4 meter lengths and having it custom cut by 80/20.

The extrusion profile I used is 40-4096, you pay by the mm for cut length. To have them custom cut use part number 40-7020 (cut to length charge).

If you want to make the cuts yourself to piece together a large frame, just get as many sticks as you need of whatever length. To avoid extra freight charges, you should use the shorter sticks so UPS or FedEx can handle it.

80/20 also has an Ebay site for overstock and not perfect items. If they have the profile you like go that route, as I've never found a problem with anything purchased through their official ebay store.

Good Luck!

See the images in my last post for answers to your frame and tubing orientation question.

As for the Seymore material, this will work with just about any material I'm pretty sure. The material I got is more stiff, but still has some stretch to it. There was no problem other than a sore thumb from pressing the tubing back into place. I suppose if you had a particularly thick material you could get smaller diameter tubing, but the size I chose gives a good mix of tension, but flexible to pull it back out without issue. I did a (somewhat foolish) test of the holding power of the tubing by pushing on the screen. Basically you would ruin the material before the tubing came loose.

I had several bulging or sagging areas after the first fit of the new Seymore material, and it was a simple matter of pulling on the "cut off" edge of the material in a certain direction, and it pulled the tubing loose. Then I could tension the fabric in that spot, and push the tubing back in to hold it there.

So the front profile of the 80/20 tubing actually became your screen's 'frame'...nice. Would you be able to post a detail shot of the hinge and it's attachment point? Also, since you used double Seymore material (white backed with black); was it necessary to also ensure your speaker area was covered in black? Finally, how did you attach the black velvet to the frame?

Thanks in advance!

Thanks everyone for all this input.

It seems that the issue with the dual-layer setup is how to get two huge pieces of fabric to stretch evenly across a large surface.

Although I love the idea of a single aluminum frame, in my case, I should consider an alternate approach in order to accomodate my two main needs: how to obtain an adequately even spandex surface and how to produce an aesthetically pleasing frame that can be switched from 16:9 to 2.40:1.

I think that the tracking system that this frame incorporates is still the best idea around and yet we have to devise a method that will provide for an even surface. The aspect ratio issue should not be that difficult to tackle once we figure out how to solve the problem with the fabric.

wow, BH, those pics and descriptions were very helpful! You even beat me to the hinge on the ceiling concept, so as jpeter requested, any pics of the hinge part would also be helpful in my/our designs.

Marc, as for your question about getting two layers evenly spreaqd across the frame - i would imagine that the most important layer to get right is the top layer (ie the payer being projected onto). the back layer should obviously be as taught as possible but i imagine it is not the end of the world if that layer is not as evenly spread or as taught. that said of course try your best since you want there to be as little leakage of light when it goes between layers. perhaps cut the two layers to exactly same size and sew the edges together such that when you pull on one edge it pulls both layers evenly?

Sewing both layers together seems like a good idea Rukus 29. However, since previous posts call for a different tension for each layer I've been thinking about having them tensioned separately.

As you point out, the front layer is the main concern. The width and length tension ratios should be accounted for, and factored in together with the dimensions desired for the screen.

Tensioning should probably have to take place uniformely when the screen is installed on all four sides so I figured that having people tension the spandex layers simultaneously while a back (structural purposes only) frame is lying on a large table or the floor would be a viable approach.

Once the first layer is being held in place above that back frame, another frame could be clamped on top of that one.

Finally the second layer of spandex could be presented on top of the previous one in a similar manner and another frame be installed on top of the black layer. This seems like a complicated approach but different tensions are required for each layer. Of course the first clip-on frame (the second one on top of the back one) should lie flat so that both layers are in direct contact.

Here is an application of this (tentative) approach: BH285's aluminum frame comes with two inside tracks. The outer track could be used to first clamp on the black spandex layer at a lower tension ratio with the very same pvc tubes described by BH285. Next, the white layer would be laid out and clamped onto the second track. Both fabrics would have to be measured up and marked with a chalk line so that the pvc tubes can be clamped on as accurately and evenly as possible. Of course some sort of extra-long stick would have to be attached to all four sides of the fabric so that a uniform pull is exerted.

I would rather not cut any of the fabric after clampling prior to testing the resulting image and sound output. Since the extra fabric would be concealed behind the black layer I don't see this as being a problem. Furthermore, this method allows for testing with different tensions on both layers.

The only drawback is that BH285's awesome frame would be entirely concealed and a new frame would have to be installed. In my case this could be an advantage since Amblone would benefit from a two-frame approach, and so would a frame that can be adjusted between 16:9 and 2.40:1.

Hello,

I know this is a very old post, and it tickled me to come across it. Had no idea it was here. This "streetglo" sandwich screen concept is my doing. I'm the guy that came up with it and contrary to the pros/cons I see here I'm going to stand by my statement that it out performs everyting I've ever seen and since 2009, that includes quit a few more materials and professional screens.

Why hasn't any of the pro screen manufacturers already done this if it's so great? I don't know. I'm a tinkerer and a gadget freak and my carreer has been in design, application and troubleshooting of electorinic systems and this included all aspects from sound to security. When putting to gether my system the thought came to me that no matter what the contrast performance of any projector a hugely limiting factor in contrast is trying to get a black to show up on a basically white or off white screen. Keep in mind that there is no black in your projector. While the scene you are looking at may appear to have black, it isn't. Now in a lot of scenes, the fact that there is no black doesn not stop the effect of dynamic range limits of the human eye from perceiving a black tie on a white suit, but it's not really black. And in scenes with high contrasting colors across the screen the dynamic light range sensitivity of your eyeball makes for a pretty convincing image. But in other cases when the light range is not so bright, and you can see a broader range of light, suddenly it's quite difficult to find anyting on the screen to appear black. This is where my "tinkering" mind began to toy with concepts that might provide a surface that way dynamically reactive to the projectory. In other words. What if we could make a screen that was in fact, jet black.. but by some miracle it's surface could detect levels of light and use that light to open reflector gates that could match incomming light head on and lighten the non reflective black mateial in matching intensity as the light that hits it. Don't get it? Think of a small sample of this miracle material the size of your fingernail. It looks like black cloth. What it is however .. in simple mechanical examples that everyone can follow, 100, spring loaded doors that are sensitive to light.. no light, spring shut, a little light, a little slack in the spring and a little white showing thru that door.. dynamically up to bright light causing a full spring open and the black door is fuly open exposing a pure white background. Now build a 100" wide screen with this material with millions of these light doors and you have a screen that produces pure and true black in a Projection Envoronment. Only problem is I have just a concept.. there is no such material although I bet there will be. LCD technology could do this easily.

So... I do have experience in highly refletive materials such as highway signage. So now that I had a concept on a screen technology that could actually produce black and not hamper white, could I do it with cheap and readilly avialble materials. The answer was yes. All I needed was to find a dark cloth that would not allow ambient light to penetrate but would be thin enough to allow amplified light to pass thru. But why pass thru? Well.. to hit some kind of backing that was highly effective at bouncing back light. Well a mirror will do this but to work the light would have to be bright but also diffused. Stock night refletive sheeting would do it. ALone it would be just too bright to work, it would produce hot spots that would make your eyes water! So the gamble was would I be lucky enough to find the right material to layer with this reflective sheeting and not take years to find it. Well I got lucky. It was the 2nd cloth I bought and it worked fantastically. I used a med to med dark grey material. I won't say it was the perfect shade but I think I could have gone darker. I lucked out both on the color of the material and how much I stretched it to open the fibers allowing control of the light passing thru the material. This light is then bounced right back through the material and into the eyes of the viewer

Here's a picture of the screen. Decide for yourself if it's a uniquely effective screen. Personally I'm tickled at how well it worked and this is not me bragging. I didnt' ever plan to have any enginnering done. This was a "tinkering" project and it could have just as easily ended up in the trash can. So this isn't a bragging post, it's a post of an experiment that turned out really nice and sharing it seems like the right thing to do. As far as I know, nobody has tried this and back when I did this I wash hoping the post by Zap would have resulted in a few others experimenting with the cloth. I am the owner of streetglo so I would know if anyone wanted to get this matrerial for their own screen.

I am still interested in seeing other efforts. If I weren't already retired I'd make this a business project but for now I'm comfortable leaving it as a hobby effort. If you want to experiment with this yourself send me a large SASE envelope. If you send a #10 put two stamps on it and I'll send a small free sample of the material from our disgards bin. Send me a larger envelop.. I'll make the sample larger, but nothing larger than 8x10 samples come out of the digards bin.

These are free.. For a larger sample put 3 stamps on your return envelope. You can contact me at Streetglo decals. Use the CONTACT US or link or use our email reply bot to get our email address. streetglo is at www.streetglo.net but this link might be marked out as spam by the forum operators here. I don't blame them. That's why I'm not posting my email. I don't want the spam either. If the link is removed just search for StreetGLo Decals and it should be the first listing in any search engine.


Decide for yourself:
The screen is now in use with an Optoma HD33 and it's gain is over the top. I will one day redo the screen with a dark grey cloth versus the med dark as the projector has more than enough light to work with this dark cloth.

1:00 EST daylight football game



Night program


Bill

Bill,

Much would depend upon the cost per square ft of the StreetGlo reflective material, as well as seeing a descriptive view of the overall construction of your screen. You don't mention what type or brand of Cloth you used in your "lucky guess either. Gosh, for you to have come up with such a application, have been a member since 2004, have only 3 posts listed, and just now come along to make mention of it makes one stop to ponder why...or at least to make people realize that when someone hits a certain standard in their viewing pleasure, they do seem to cease looking for newer/better alternatives.

You said "The streetglo" sandwich screen concept" was your doing, but gave no link to such a prior discussion. No reason to doubt that, obviously. Help us out and post such a link for review.

Certainly it appears to work right along the lines of Mylar or Mirrored underlayment, and as was noted several posts back, the use of a darker fabric does help mitigate the excessive reflective properties of such materials. The multilayer "Light Fusion" principle has in fact been utilized by Mfg Screen makers...a very select few....to some degree, but as to the material selection being akin to what you have going for you, that would be a problematical guess at best. As you said, if there would be a demand for such material, you'd probably be aware of it. There are patents out there that do cover the broad usage of multilayer materials that employ a reflective base, so obviously something /several things are...or can be...and have been used.

But as to what is "best" and more importantly, what is both affordable enough and easy enough to use that the average DIY'er can aspire to consider such....those are the most relevant questions that need answering.

One cannot deny that your example is presenting a very impressive image. As to it being "uniquely effective", it would have some competition in that regard, I'm sure. To receive that label, it would have to have to undergo considerable scrutiny. Simply saying, "...it out performs everything I've ever seen..." isn't very productive, and lemmie tell ya, such statements made even in the roseate glow of a great looking screen and backed up with a multitude of exceptional screen shots can result in the Goblins coming out of the closets to gnaw at your leg. Believe me...I know.

In the posted images, I see that as much ambient daylight as possible has been blocked, without resorting to the use of Blackout Cloth window treatments. That's pretty "real world". The first shot is the most telling, although seeing a shot taken with indirect / directed Incandescent lighting present, and/or a higher degree of ambient Sunlight would tell more of a tale. So would a shot taken at a more severe angle, as such light-reflective material usually has a limited range of "direct reflectivity". The other shots "appear" to be taken in a darker environment, but in any case, zoomed shots really are not an effective judge because the camera is metering only the screen's content, and the zoom itself attenuates the screen's light output. However, as a erstwhile judge of Screenies, I still must say they do look excellent.

Personally, I like how the Screen acts like a partition for the open Stairwell. I've done a few similar projects, and that one looks very well thought out.

All the more reason for you to share some serious details regarding the construction and your thinking surrounding it. Such information will do far more to encourage any "fence-sitters" to jump down and get involved. Using stretch fabric is becoming more popular ...primarily because of the desire for acoustically transparent screens....but in reality, the lightweight, non-permanently mounted aspect of a Fabric Screen holds promise for many with non-dedicated Theater rooms. Other than trying even darker cloth on top (...a shame you didn't include a shot of the screen without any image...) it would seem you have already done the bulk of any necessary 'experimentation".

In any case, constructive sharing of any "new" working DIY application is the key element, and having done your own DIY example and sharing details helps ward off complaints that it's simply a promotional ploy to sell something you provide. (...certainly not the case here or you'd not have waited so long...) That sort of thing can be a sticky wicket on here, and in the past has negated a few potential breakthroughs, or delegated them "Mfg Rep.status". It's always a bummer, but sometimes necessary.

Here's hoping you don't wait several years between posts again.

Nice looking screen. How large is this stuff available in? Can you share a close up shot to show weave/ grain? A home made HP is a pretty cool concept.
Edited by dlouw - 6/13/12 at 4:35pm

Dear Mississippi Man,

Wow, what a welcome response from you and very happy to receive it!

You are riight, once I figured out my screens I didn't post any more but you have been in my bookmarks for at least as many years and while no posting, you have been my reference library for many brain stumpers I've had to tackle .. mostly having to do with getting into service menus, adjustments, gear. So while not an avid poster, I am an avid reader.

The funny thing is I was shopping for a deal on the Harmony 1100 and had missed the $159.00 refurbished sale Logictech had, so being the thrifty guy I am (and impatient to wait for another such sale), I decided to back door shop for the hint of any distributor or dealer leads that might still have access to these Harmony remotes.. Took me about 4 days but I did find some of the Refurbished stock at $169.00 and that made me smile.... such a deal! But in my search is when I caught my company name in this post and immediately realized they were talking about my project. It took me way back because at the time I did this it seemed nobody was really interested in it. I know follow two AV forums and this is one. There is one more. I thought it was here, but I did create a big posting with what I did, how I did it, etc. And after I found this posting in this thread, I searched both your forum and google for some of the terms I remember using and I just don't see the post. I actually thin it was here. But I didn't find it. But if I understand your request, I think you wanted me to show this was my design/concept and share more of the technical details. I'll be happy to do both. I'm beginning to wonder if I made the post under a different account name. Because it's so later here I will search another day but I can tell a little more about the construction. If enough folks show interest in this post I'll take the time to make some new shots with an OPTOMA HD33 projector installed since the original shots. It may be worth the time because the OPTOMA HD33 is very "punchy" on this screen.... maybe even too punchy and you will get hot-spots if you dont reduce some of the light.

Keep in mind the design is really super simple.... anyone can do this. It will take a little experimenting and a little patience. The key material here is the reflective sheeting. It's a vinyl roll of bright reflective vinyl used to fabricate highway safety signs. While it comes in all colors, any color works for this project because you are not going to use the color side. On our vinyl, the adhesive side hapens to be the actual base layer of prismatic material the entire finished color side is built upon. So the reflective stock is stuck on the back of the screen using the normally never seen tact side as the face for the purpose of the screen. The cloth is just a simple thin material similar to ordinary Tshirt material or the polyester thin material that is often used to make ladies blouse. The key element here is:

A. the material is tight knit and a thin but smooth surface material
B. the material will stretch.. and at close to doubling length if stretched to the max by hand.

The reason I offered the free samples is because finding the right material means not just buying it and putting this together. it means building a small 1x1" stock square frame about the size of a floor tile and using it as a frame to stretch the material over... then stick the reflective sample on the backside and go test your projector. My selected material was like a blouse t-shirt like stock (think a guy's cotton t-shirt but a silkier weave) I believe it was polyester. Held in front of the projector screen loose, it blocked close to 100% of the light. The right stretch opened the weave fibers to the point that it appeared same brightness as unstreched stock but holding a white card behind it I could see and estimate that about 45% of the projector beam was penitrating. That was ideal for my room. Other rooms could be more or less.. Keep in mind that we're so use to fighting for more brightness that you might just skip right to putting a max stretch on the material then putting up what may be $120.00 worth of sheeting to the back side of ta fully made screen only to find you'l be tearing it off because it's just way over driven.

If anyone wants to do this project, you can start with the intention of using the reflective sheeting as your backing but if you never get it quite right, well you can abort and proceed with puling another screen material over the screen frame. ALl the rest of this design is fully compatiable with all the materials one might buy as screen cloth.

There are a few key points to follow when you make this screen. It's past 4:00 am here and I need to be in bed and not finishing up this document, but I will stick with describing everything in detail. This includes a couple of tricks and a skirt you'll need to make that attaches to the top of the screen to hold the weight of the sheeting. If you don't secure it, it will sag and cause a wave in the front screen and that would create a terrible appearance. The materials total were about $200.00 and includes a dirt cheap trim concept that gives a royal appearance to the screen for next to nothing. Here is a photo that better shows the classy and expensive VIP appearance of the screen.

I'll get back in a few days and post some more about the project assuming this posting creates interest and folks are talking here. I'd be honored to contribute.

This shot is to show a higher level of exterior light entering the room
(The finished frame shot has to be taken. None of my original photos included the finished frame... I'll take a new photo with the HD33 on my continuation post.



And this is a totally dark room. Walls are Purple Plum.


And for AMUSEMENT only, here's a shot head on with flash. Why the flash? Well. it might give some insight to the retroreflective nature of this design. Im guessing.. and it's only a guess, that other shots of painted or conventional screens will show just the flash, no image.. or one that is even more substantially washed out than this screen. It will be fun to see. Post your photo if you take it. But kindly note the white diffused spot on the screen. It didn't occur to me until just now that this demonstrates what's going on really with this screen. That hot spot actually is showing the pass thru-bounce back retro-reflectivity. This is why I think this screen will out perform ... all of them. But like Mississippi Man said, that's a pretty tall claim for me to make... And he's right. I'm assuming this.. not backing it with real world tests. What I can tell you is that in 2009, i obtained actual cut samples of screen material from every (all three at the time) vendors of both no gain and high gain screen material and a sample of drape backing and a sample of silver painted artists cloth. This screen outperformed all of them in reflectivity and all of them in contrast range. There was a .9 gain and I think a 1.4 gain material I received that would have been my first choice. It looked like the dark silver screen material used in professional set-ups. It was very bright. But it also amplified the blacks.. The 1.4 gain was visually linear across the brighness range and it raised the base black level several steps brighte as well so increased brighness had the cost of decreased contrast range. I'm not clear if it was 1.3 or 1.4. I even think there was a 1.5 but that might be wrong. I'm working from memory.

I think if I can find my orignial post.. I clearly remember taking photos of all these screen material swatches taped onto a wall and live under the projector light. It might be in the original post. It was shocking to see some of the results. A base matte material that was fairly cheap actualy provided a brighter and dynamically deeper contrast range over sandbead screen (I don't know what it's really called bu tthe material that looks like white sand paper).



Thanks,

Bill
Edited by blake2415 - 6/14/12 at 3:38am

To sum up the construction costs, it's well under $200.00 including the DOT 3 Highway Enginnered vinyl.

Figure about $3.00 sq ft for the reflective sheeting about $120.00 for a 10 ft diagonal screen. The frame was made with three 2x4's ripped into 2x2's. A simple squared rectangular box as the wrap around stretch frame and two inserts diagonally to support the frame. This would equal a rectanguar shape with 4 2x2's vertically thru the width of the screen and a 2x2 capping the top and bottom.

Then lay the frame down and decide which is the top side. On the top side staple on a skirt. The skirt is any material that is thin and can be bonded to with packing tape or any other think high stick wide tape. Make this skirt about 4" tall and as long as it takes to reach from the left to right edge of the frame with the material pulled snug. I used a 2 or 3 mil painters poly coth Ihad but you can use any material just be sure it is strong and thin. SNug it across the top of the frame on the screen side. It will be covered over on the front by your screen clot but standing on the back open side you will see this skirt exposed with 2" showing just below the frame. the other 2" is stapled to the frame and the purpose of this is for the first layer of reflective material to anchor to this rigid starting point and not rely on the screen cloth to suspend it's weight. Otherwise you'll get a wrinkle as the cloth gives way a bit to the weight of the reflective sheeting. This plastic skirt serves as a transparent anchor point to hold the weight of the material while the remainder bonds to the screen cloth but does not rely on it for support.


The screen cloth was about $12.00 and the wood strips from 2x4's were about $10.00. The only other expense was the screen black out cloth. the black around the edges was clamshell moulding on the top and the bottom. On the left and right side was trim strip wood that is about 3/8 thick and 1.75 wide that lay flat on the screen edges. They were then hand painted with flat black trim paint.

The columns on the left and right of the screen create a real high end theatre screen appearance and were made with a section of 6" pvc sewer pipe. On a table saw I just cut out a 2" wide gap the length of the screen and this wrapped arond the left and righ edge of the screen. I'll provide a close up shot of this so you can see how I did it.

Here is a picture of the 2009 screen project but with my OPTOMA HD33 projector. Before evaluating this for set-up, it's not. It's been mounted, fairly well focused but not tuned up. I have to move the projector mounts as the optoma does not sit center on the mount like the old projector so Ihaven't tried to fine tune the "fill" or the image settings. I did have to drop the projector down both in brightness and contrast but have not yet doe the same with color which is too intense at this time.

This first shot is a side shot taken at 11:00 am where the sun is still directed into the windows on the screen right side.







This shot is more revealing of the performance of this design. We never watch TV this way but the deep dark purple walls help a lot and the Projector and screen material keep up with the large intrustion of light. Not seen is a table lamp at the sofa.

Bill

24" wide rolls by as long as you need. my screen took two and 1/2 strips running horizontally with a full second strip that laps the first one by a few inches, then a final third strip ripped to about.

I'll be taking more photos if folks here show more interest and I'll get a close up of several details.

Bill

.

Please show were the seem is in your shots. Close ups would be nice too. This may be nice for 3D. Any idea of the gain?

Just the same as when you use Mylar behind such material, I'm certain that with a very minimal overlap and no darker line existing at the union point, there would be no possibility for you to be able to ever see a scene behind the cloth's surface reflection. Of course Mylar comes in 60 inch wide rolls, so only the very largest screen project would have to use two rolls that would have to overlap.

BTW, Mylar has in fact been used for this type of application before and it has done a splendid job. But simaliarly the surface weave of the dark grey material must remain tight. You only stretch spandex far enough to remove all wrinkles. I personally recommend that the project as outlined above the attempted by a few other members .
Edited by MississippiMan - 6/23/12 at 8:06am

Sorry for not answering this before.

There are no seams that can be seen. I was concerned as well that a seam might show but I can not find even a hint of one. And as far as 3d, my 3d looks great on it. I don't know much about the mylar sheeting mentioned, but unless it is DOT approve reflective sheeting, I would imagine it would not have the same characteristics but I really don't know.

Bill

Hi Bill,

Sent you a PM and would like more info on the reflective vinyl method you've employed here. Your results look solid and I have a room that I won't always be able to control the light to a solid degree. I was initially thinking of going with a sintra board and painting it silver fire 2.5 4.0, but after looking at how much work that is going to take, i'm leaning towards wrapping a frame/sintra board instead. With the ambient light performance of your setup, that's looking VERY attractive to me right now.

Thanks for sharing!
Brad

I sent you a PM reply. I'll be happy to send you a 12x12" scrap sample if you are willing to test first. I only want great results so a test is the way to go and it will prove your choice of screen cloth before we even start. Thanks.

BIll

Great, thanks Bill!

blake2415:

I used the contact form on your website to request info on your screen material (and for a sample of the reflective vinyl).

I've previously ordered some gray screen material from "Carl's Place" and it quite frankly sucks. It's all shiny and grainy looking... almost like it is "glittery". Totally distracting... I can't believe he is advertising it as projector material for "HDTV". This would be OK for a presentation... but even then your audience might be annoyed by the glittery specks all over the screen.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230725140923

It's awful... just awful... I hope I can get my money back.

I hope your design is much better.

Thanks,

Edit: Nevermind... sorry to bug you. I wasn't thinking and realized again I want something I can roll up. Doesn't sound like I'll be able to roll up that vinyl backing stuff you're using. Also I get the feeling your design would be a bit too intense brightness wise for me. I'm not thinking straight because I'm tired and annoyed that all my work was for nothing (well at least I have the projector mounted), and stuff that was supposed to be "projector screen material" ended up being WORSE than my damned wall.
Edited by damag0r - 12/29/12 at 1:27pm