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A Tale of Two Screens...SF 2.5 4.0 and Spandex, White over Black

6K views 33 replies 9 participants last post by  MississippiMan 
#1 ·
Came a time where in a smallish area someone decided that they could not have a very large screen, yet being enamored of the Panasonic 8000 and having a 2.39:1 C.I.H. setup, determined to go with a 2.39:1 format at a 104" diagonal (40" x 96") size Painted Sintra board screen.





Then came the time to actually set up the system and waddya think'ed happened? The unanimous decision was that the screen was just too damnable small.

Issues arrose however as the Sintra was glued to the Drywall, and taking it down was going to be a PITA, and besides all that, there are 4 Audio Transducers applied to the Drywall directly behind the Sintra, and no one wanted to risk tearing undue amount of Paper off the wall concerned.

What to do? I know! Let's make up a acoustically transparent Spandex screen 51" x 122" (132 " diag.) and simply hang it over the existing screen. :kiss:

This has to be done quickly....no time to wait for Spandex World to get Silver Milliskin in stock, so I decided now was the time to try a White over Black Milliskin variety.

Ordered up 4 Yards of both, had it shipped on two rolls (nix on the folded method) and today I will build the Frame.

This does present a unique opportunity to show the difference between the two applications. Naturally the small SF will blaze compared to the much larger Spandex screen. But it is image clarity that is most important here andthis experience will help quantify the performance of Spandex vs Painted.

The latter not really being in question here, but also one must realize that there is little else available that will allow the continued use of the Center Channel Transducers as well as avoid any necessary wall refinishing.

So onward.......pictures of the build process will be forthcoming, and screenies perhaps by early this weekend.
 

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#2 ·
Looking forward to this direct comparison. Especially interested in the difference in contrast and black levels between the two.
 
#5 ·
Well........................,

Santa gave me a lump of Coal. :(

Got to work on building the Screen Frame, using my trusty Kreg Pocket Screw Jig (...of which I cannot recommend too highly....)



No Braces or such needed to construct a really sturdy frame.....



I got the Frame assembled and hung over the existing Screen to confirm placement criteria......Mo' Bedder size fur shur !!!



Now came the time to open the very well wrapped rolls of Black and white Spandex. I was all a'tingle.



Then...upon close inspection of the Masking taped ends, what do I find? A very disappointing notation on the Tape stating that each Roll contained "3 YARDS", not the 4 Yards ea. I ordered.

Screeeech......everything slams to a stop, because no way 108" of Spandex is gonna stretch out to cover a 122" (width) sized Frame.

In truth, I am not sure who is to blame in this, a mis-ordered amount by me, (...doesn't make any sense at all...) or a miscue by them in fulfilling my order. (...what I hope is the case...) Whatever, it means early Monday AM I must place another order for 4 yards, shipped Rolled via 2 Day Express, and get this thing over and done with before next Friday, as I absolutely DO NOT intend to be working on anyone's projects after Monday the 22nd. :mad:

BTW....since I do not do many Spandex Screens, if anyone is interested in the 108" x 60" Black & White Spandex, it's available at cost....but I'll pay shipping.
 

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#7 ·
Well........................,

Screeeech......everything slams to a stop, because no way 108" of Spandex is gonna stretch out to cover a 122" (width) sized Frame.

BTW....since I do not do many Spandex Screens, if anyone is interested in the 108" x 60" Black & White Spandex, it's available at cost....but I'll pay shipping.

I'm guessing if you're not comfortable with it stretching to cover 122" width frame that 3 yards won't be enough for my upcoming 135" 16:9 (66x118) screen?
 
#6 ·
Actually, I just effected another order online, then called (Spandex world is open on Saturday! Who'd a thunk it? )

Found out that I was to blame since the order was placed online. leastwise that's their take, and sadly I must be inclined to agree. :eek:

In any case, I will hang the Panny based on the Screen's Frame location, take some screenies of that picayune, little SF screen, and be loaded for bear when the Spandex re-order arrives on Wednesday.

Now I must slink off to a corner of the Barn and get small.
 
#8 ·
3yds/9ft would only need about 1ft of stretch to get around a 135" 16:9, so I'd expect that to be perfect.
..just re-read the width on MM's screen-build..
Wouldn't 9ft of spandex be fine for a 10ft screen-width?
 
#9 ·
At 20% stretch, it should more than stretch to cover a 122" frame width. I'm guessing MM must have a reason he wants minimal stretch from the spandex -- just enough to keep it unwrinkled but not enough to make it thin and reduce gain, maybe ?

I'll be interested in his reasoning, because I was thinking of using just 3yrds for a 128"x60" image area.
 
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#11 ·
The replacement Spandex arrived today. I have scheduled up a trip to stretch out the material onto the frame for tomorrow after 12 pm.

It is my intent to not vacate the premises until I have an image up onto the screen.
 
#12 ·
Could you please take a piece of plain white paper with you and place against both screens during picture taking ? Possibly also a piece of scrap Flexi-white if you have it ? It would be interesting to see all four materials' gains in direct comparison.
 
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#13 ·
I just don't think it's possible, as because of the Spandex snafu I'm far behind on this project, ....the Owner is taking off a half day to be there, and they still have me having to wait to come in until after Lunch.

Also, I have no Flexi on hand.

Besides, this screen will have a gain of 0.7, being White over Black Spandex, and the capabilities of such a low gain screen, as well as it's limitations are already well known and documented. Unless you plan on using either of the requested test materials, the only end result is going to show the gain difference between them and a Spandex app....and as I stated, that is already well known.

The screen is 120" x 50" (130" diag.)
I will set the PJ at 14' -7" to achieve 13-14 fl ...which should be sufficient in the well light protected Nook the screen will reside in.

It has been my experience that although the Spandex looks on paper to have a low gain, using an appropriate PJ overcomes that limitation. But only if one does use such. From the Get-Go we / I have never suggested using any Pj of less than 2400 lumen for any Spandex application over 130" diagonal.

Now I might be able to revisit this location after the press is off, but my order today is to make the Screen, hang the PJ according to it's location (screen), assemble a A/V Rack, install equipment, and get this Puppy up and running before the weekend.
 
#14 ·
I didn't realize you had so much left to do. I thought with the last minute addition of the spandex screen over the SF, and the delay in getting the spandex, that everything else would have gotten done over the last week. I'd hoped you would have plenty of time for screenies today after assembling and hanging the spandex.

I've seen the 0.7 number for white over black and the 0.8 for white over silver and the 0.9 for white over white, but I didn't realize they were more than estimates and I don't recall seeing any direct comparisons with the flexiwhite or even white copier paper set on a screen. I'll look again.

My problem is that I haven't used anything but my mis-labeled VuTec for 13 years. I recall it being slightly brighter than my previous BOC (Joannes) screen and I recently noticed it is NOT as bright as plain white copy paper. So I don't know what I am coming from in trying to decide between spandex and flexiwhite. My new screen will be the same size as the VuTec 60x106=122" when in 16:9 mode but masked to 54x128=138" when in 2.40:1 mode with a simple dual prism HE lens. I'd like more contrast for my W1070, but not sure how much gain I can sacrifice compared to what I now suspect is my VuTec's ~1.0 true gain.
 
#15 · (Edited)
That's interesting. My VuTec is about the same relative gain to white paper as the white over white spandex. Although as you say, when stretched the gain might be lower. What was behind the spandex ? Your ambient light rejection screen ? The white over black shows dirtier whites than screenies others have posted on the spandex thread. I don't need the spandex for AT reasons, but it is still tempting to just buy some to play with and keep the flexiwhite in mind as a backup.

I just re-read the whole 110" Spandex thread and it is definitely matte silver people have used.
 
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#16 · (Edited)
Another Update...................

Got the Spandex Stretched out. Took enough time and consummate care so as to be assured that the material was stretched not too tightly.... just enough. I did stretch the Black more however, because I wanted to use it has both backing and a resting place for the White, so as to not have to stretch it so much. That lack of stretch on the White helps it's surface reflectivity stay as high as possible, while the taunt Black keeps both layers suspended above the 1/4" recessed central supports. Also...the tighter stretched Black allows proportionately more sound to pass through.

So here is a shot of the Black Spandex stretched out onto the 2.39:1 Frame

Cue :
Thus Spoke Zarathustra


"It's full of Stars!"

Actually, there was some mufti-colored Glitter sprinkled around on it. :D

Here is the completed screen hung in place.



After I recovered from almost 3 Hours of Stretching, stapling, and trimming, I assembled the 55" x 23-3/4" x 22"(deep) 5 Shelf Professional style Metal Rack that will go into the far left Corner. Put together in the garge, it took 3 people to lug that 200 lb monster up the stairs! Sheesh...Dude has just a Receiver, DVD, and Cable Box going in, yet he purchased a Rack that can hold 8 components. :rolleyes: Well, it was on sale at Best Buy for $700.00 off. Yeah, it's a $1000.00 rack. :eek: And it has locking doors Front and Rear so I suppose what with 4 kids in the house, all under 12...that was also considered.

Even with all that, I was concerned that the Rack would intrude upon the Screen, but fortunately it come up about 7" short of the left side.

Anyway....all that took me about 5 hours to accomplish, so no PJ went up. That is today. I will try to drape a Double Thick piece of White Spandex over one side so as to show the difference between White over White, and White over Black, but that's about all I can manage at this conjecture.
 

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#20 ·
Yeah....You can't use the "Quick Response" widow unless you click on the "Go Advanced" Button that brings up the Attachment link (paper clip) beside the "Smiley Face"

Otherwise, you the poster will see your images, but unless there are Thumbnails visible at the bottom of the page, no one else will see the images.
 
#22 ·
It is always tough to tell depending on what camera was used, but that looks a bit whiter than other white-over-black screens people have posted. So maybe the relative difference in stretch also has that effect ?

I hope your screenies with a movie will have a few in ambient light as well as dark room shots.
 
#23 ·
Well Gowllleee.......

I finally got this accomplished.

I had HDMI issues, because I had originally ran a 25' cord for the smaller screen because I planned to set the projector as far forward as I could. The change to a much larger screen required a set back of an additional 3'. Now even that was not too bad, as all I had to do was add a Male / Female extension at the PJ's location. However then the Client came up with a 55" tall Sanus pro Rack (see photos) with a solid back panel, that required that all cords enter at the bottom. With the Receiver on the Top Shelf, and the existing HDMI cord coming out of the wall at outlet height, there was not enough length to manage the connection.

So I added another extension and sh_t,.....no image with 1080p BluRays...only Sat/HDTV

Soooo.... I had to get a v1.4 4K 35'er, and dismiss both extensions. No issues then.

Here is the end results, with images taken with my Galaxy 4s at 20' under full lighting (...w/Can Floods no less...the Spots are yet to come...)










So it appears that a pretty darn sizable screen that has a Black Milliskin backing under White Milliskin offers up a modicum of ambient light viewing potential, when combined with a PJ with adequate lumen output.

I gotta go back again to Trim the Screen, program a Harmony Remote, and put a Plate onto the hole where I ran the new HDMI cord...sometime after the Holiday. At that time I'll take "Eye Candy" shots like the "Quantum of Solace" one above. I've stated before that most such shots are really the easiest ones to take and to show "quality" under adverse conditions. It's the shots that are takien at a distance well beyond the PJ's placement, ones that encompass a larger percentage of the room itself than screen area, that really tell the story.
 

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#24 · (Edited)
It does look like an ambient-light fighting screen, but that's partly the magic of a bright projector and a non-HDR camera setting. I imagine they'll be even happier once the spots are in.
The bigger spandex looks really nice.
 
#25 ·
According to Projector Central's table, since the screen is at most 0.7 gain and getting it's hit from the 8000 at 16', it is only getting 13 fl.

By any real measure that has it standing up extremly well without the aid of any magic....save the "stretchy" kind. :D
 
#27 ·
MM, have you ever helped anyone who was unhappy with their spandex screen do an SF treatment using it as a substrate ? Either just a light coat to improve gain and contrast while still AT or a full on multi-coat SF and giving up the AT aspect ?
 
#26 ·
Granted that the floods are far from the screen itself, the white table under the screen it lit up, yet the image looks uniform -- not washed out on the lower or right hand edges where the table and door should be reflecting at least a little ambient onto the screen. I think that bodes well for my room and I'll keep the white over black as a candidate. The W1070 is a bit brighter than the AE8000, so I should be fine.

I'll still be interested in those screen candy images and possibly with the scrap of white spandex or computer paper against the screen.
 
#29 ·
So from reading you recommend stretching the back layer (dark grey or black) a bit more than the top layer of white? Im really trying to understand the best method to getting the acoustic transparency to be at its best with sacrifice of picture, sounds like this is a good way to go.
 
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