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post #1 of 19 Unread 06-16-2017, 09:08 AM - Thread Starter
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LED Backlighting

Hi,

I am planning on buying the Cinegrey 3D and building a frame with LED backlighting.

Do I need to prevent the LED lights from going behind the screen, or will this be ok?

I have seen a lot of info on building your own screen but not many that include how to do it with the LED's.

Thanks!
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post #2 of 19 Unread 06-16-2017, 10:00 AM
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Usually you'll add a small wooden lip around the back of the screen frame about 1.5inches from the outside edge...this will give you something to guide the LED strip around the screen's back and also let you attach the strip do it's facing outward (alternatively you could attach the strip around the back of the frame in a similar location except with the strip facing the back wall).

Do you already have a plan for the frame you want to build?

Easy $25 DIY black (or any color) ALR paint +$40-$50sprayer screen mix smooth/clean and very easy to learn spraying with little/no mess.
Simple $25-40 DIY black/dark-grey ambient-light rejecting screen, grab two things from a local store..mix..roll..done.
Quick <$250 dedicated black-fabric theater room "A store that sells blinds can help your picture more than a store that sells projectors many times." -bud16415
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post #3 of 19 Unread 06-16-2017, 10:51 AM - Thread Starter
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Hey Ftoast,

My plan is not set in stone, but I was going to use 1 x 4's as I have seen in most directions. I read someone else used aluminum for the frame.

If I didn't put a lip around the entire back of the frame for the spacing and to put the LED's on, will LED light shining behind the screen mess up the image? Do I want to completely block all LED light from going behind the screen to preserve image quality, or is this not a concern with Cinegrey 3D?

If you have any links for tutorials on how to build a frame with LED, that would be much appreciated.

Thanks!
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post #4 of 19 Unread 06-16-2017, 11:42 AM
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The CineGrey material is quite good at blocking light from going through it, so having the strip bleeding light behind the screen shouldn't hurt the image.

I'll try to see if I can find some pictures/links to others' lit screens.. hopefully someone else will also be able to jump in if I'm being too slow.

Are you thinking about using the 1x4's the deep way like a shadow-box or the wide way like a picture frame?

Easy $25 DIY black (or any color) ALR paint +$40-$50sprayer screen mix smooth/clean and very easy to learn spraying with little/no mess.
Simple $25-40 DIY black/dark-grey ambient-light rejecting screen, grab two things from a local store..mix..roll..done.
Quick <$250 dedicated black-fabric theater room "A store that sells blinds can help your picture more than a store that sells projectors many times." -bud16415
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post #5 of 19 Unread 06-16-2017, 11:44 AM - Thread Starter
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I tried to search for "LED" but I get results from all forums and not just this one. I can't figure out how to search in just this forum.

I am planning on using the 1 x 4 flat like a picture frame.

Thanks!
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post #6 of 19 Unread 06-16-2017, 11:52 AM
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That search bar's left side, click the little icon and switch to VB search instead of Google search..then choose advanced search right below the search bar.
Near the bottom/right of the options menu advanced search you'll see "search by forum section" or something like that. Inside that menu you'll want to uncheck the top option which makes it search everywhere and select one much farther down..DIYscreens.

Holler at me if I screwed those directions up..i THINK it should be about right.

Flat like a picture frame you'll want to add a small lip/trim around the front near the outside edge to push the material out away from the frame itself unless you'll be using thick/3inch-4inch borders instead of thin borders or zero-edge.
Thick borders will hide it, otherwise without the front bump-out the material will lean on that entire 4inch frame and the inner edge well give you a slight line/shadow around the screen about 3 inches in from the edges. The little ledge along the front keeps that from happening.

Your 1x4 picture frame style should make attaching a light strip easier and allow you to choose exactly how far back from the edge and which way they'll be facing (back or outward).

Easy $25 DIY black (or any color) ALR paint +$40-$50sprayer screen mix smooth/clean and very easy to learn spraying with little/no mess.
Simple $25-40 DIY black/dark-grey ambient-light rejecting screen, grab two things from a local store..mix..roll..done.
Quick <$250 dedicated black-fabric theater room "A store that sells blinds can help your picture more than a store that sells projectors many times." -bud16415

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post #7 of 19 Unread 06-16-2017, 12:15 PM
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Search Bar? We don't need no Stinkin' Search Bar!

I have several projects that used Flexi-White on a Frame with LEDs.

Almost all that sported LEDs also had some degree of Trim around the Screen, but 2 were Zero Edged (...way before Zero Edged was "cool"...)

The safest way to do this would be to construct the Frame of 1x3s on edge, and have it mount to the Wall via 2 French Cleats...on at the Top and one at the Bottom, so that the Screen Frame is pulled up against the Wall once set into place.

Also, if a Zero Edged look is what you want, adding a 1x2 perimeter edge (on flat) on top the 1x3 will provide a depth of 1.25" from the 1x3 Frame and the outside edge of the actual screen, and that will direct more of the LED effect to right angles, and across the Wall. Or the LEDs can be mounted on the back of the 1x2 to direct light 1st against the Wall. (better)

Here is a basic diagram. Without any stated size, it can only be generic.



If indeed you want to try going with a Flat 1x Frame, the absolutely the extra 1x2 will be required. And that's fine as it will eliminate the need for any Fabric Standoff as well as provide the needed recess for the LEDs.

However you will not be able to "seal the Frame" against the Wall when going "Flat". It's really not the most ideal way to build a frame....as that 3/4" depth is not really enough depth, and that the LEDs will shine VERY bright against the wall.
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Last edited by MississippiMan; 06-16-2017 at 12:22 PM.
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It's going to take a little time to digest those photos but thanks for posting them.

I think I would like to go zero edge. Thanks for the tip about having the led's facing/parallel to the wall.
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post #9 of 19 Unread 06-16-2017, 05:55 PM
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Quote:
Originally Posted by jmbtexas4 View Post
It's going to take a little time to digest those photos but thanks for posting them.

I think I would like to go zero edge. Thanks for the tip about having the led's facing/parallel to the wall.
Screens that feature LEDs at right angle to the walls shoot light out so far that it often illuminates the side walls and ceilings so much that the reflections off those surfaces detract from screen performance.

A softer Umbra of light surrounding the screen creates a gently glowing frame...not a intense, overbearing ring. The same principle was used in many LCD and a few Plasma TVs, but never to the extent one sees with Front projection screens. No, with TVs it was there primarily to improve the perception of on screen blacks being deeper (...especially with the earlier LCDs...) as well as to ease eye strain when watching content in the dark.

Nowadays, it more a cosmetic thing...but it should never go so far as to detract from or reduce image quality. But overkill being what it is...irresistible to so many...often rules the day....and ruins it as well.

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post #10 of 19 Unread 06-17-2017, 11:07 AM - Thread Starter
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Is it easier to build these LED's with trim or zero edge? Does the frame need a gap from the wall in both situations, or can the trim serve as your gap?

On a 120-130" screen, what is the ideal distance between the LED and the wall? In the example above with the LED on the back of the 1 x 2 facing the wall, we are talking roughly 3 inches right?

Last edited by jmbtexas4; 06-17-2017 at 12:46 PM.
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post #11 of 19 Unread 06-17-2017, 05:08 PM
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Quote:
Originally Posted by jmbtexas4 View Post
Is it easier to build these LED's with trim or zero edge? Does the frame need a gap from the wall in both situations, or can the trim serve as your gap?

On a 120-130" screen, what is the ideal distance between the LED and the wall? In the example above with the LED on the back of the 1 x 2 facing the wall, we are talking roughly 3 inches right?
Myself, I would design in no less than 1", but no more than 3.5"

That is why I almost always use 1x3. The 1x3 is only 2.5" tall on edge...and that is a good distance that helps diffuse the intensity of the LEDs, reducing "wall shine".

Making sure there is enough depth from the leading outside edge is also important. The two, depth to edge and depth to wall both work together to create a glow...not a overly coherent "beam"

If you had to build a Frame "Flat", I would use 2x Lumber such as 2x3, but such a Frame would out of hand require Trim anyway, such a 1/2" x 2.5" or 3.5" Velvet Wrapped Base.

Now one thing that can help mitigate some of the brightness issues is to chose LEDs that are dim-able.
You still want some depth to the outside edge, but Frame depth can be reduced, so that you could go Flat.

But again...a Flat build presents a broader contact to whatever material is being used, and that is why a raised perimeter is so essential. Also, any Vertical Bracing really doesn't add much as far as helping prevent "Frame Twist" from corner to corner, so you must really work harder to attach such a frame on all four corners against the Wall surface. French Cleating is not an easy option under that circumstance.

A "on Edge" build is very much more rigid and can be more easily build to be "square" diagonally, and "plumb" as far as being Flat.

On edge is the way to go, and creating a right angled "L" type edge the best way to engineer in the needed overlap.

The final choice being yours, and frankly, unless you understand every aspect of such a build, it's best to strictly follow the directions given...to a "T", using the recommended materials and tools.

To provide that for you in diagram form, all that is needed is a set of the exact, desired Screen size dimensions.

Your move.

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post #12 of 19 Unread 06-17-2017, 10:37 PM - Thread Starter
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Ok MM, thanks for that info!

First of all, I am planning on buying LED lights that I can change colors and dim, so I will have control over brightness level.

Per your recommendation, I would like to go with the "on edge" frame...and also "zero edge" screen with "no trim." I hope I have the lingo right. Ha ha.

That being said, I am planning on buying the Elite Screen Designer Cut ALR CINEGREY3D which has dimensions of: 135-inch Diagonal, 16:9 Aspect Ratio. View Size: 120.0" W x 68.0" H.

Before I can give you final figures on screen dimensions, let me ask you these two questions:

1) What is the maximum size screen you could build with this 135" diagonal CINEGREY 3D (given that some material will be lost on the wrap around)?

2) How many inches of space would you recommend between the top of the screen and the bottom of my crown molding and the bottom of the screen and the top of my table?

See attached photo of my room currently. The image in the picture is 142" diagonal...touching the crown molding and two inches above the table.

Thanks!
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post #13 of 19 Unread 06-19-2017, 08:25 AM
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Ok MM, thanks for that info!

First of all, I am planning on buying LED lights that I can change colors and dim, so I will have control over brightness level.

Per your recommendation, I would like to go with the "on edge" frame...and also "zero edge" screen with "no trim." I hope I have the lingo right. Ha ha.

That being said, I am planning on buying the Elite Screen Designer Cut ALR CINEGREY3D which has dimensions of: 135-inch Diagonal, 16:9 Aspect Ratio. View Size: 120.0" W x 68.0" H.

Before I can give you final figures on screen dimensions, let me ask you these two questions:

1) What is the maximum size screen you could build with this 135" diagonal CINEGREY 3D (given that some material will be lost on the wrap around)?
That would depend upon how much overage of material the 135" diagonal CineGrey comes with.

The size measurements you listed do not equate to 135" diagonal...they add up to 138" diag.

135" @ 16:9 is 66" x 118"

But a quick and dirty answer would be, assuming that at that size they give you at least 70" x 122" (2" extra on all 4 sides) and your wrapping over 1x3s, then 135" would be correct

Quote:
2) How many inches of space would you recommend between the top of the screen and the bottom of my crown molding and the bottom of the screen and the top of my table?
Both the Ceiling and the Tabletop WILL wind up being detrimental reflective surfaces as far as projected light goes....but add in the LEDs and at the size image your showing, with the proximity of the Trim / Table, you must expect a very predominant reflection off both. So you might well expect to have to make allowances for suppressing reflections from whichever surface is the closest to it's respective Screen edge....or both.

Really...as far as the Top & Bottom edges of the screen, you don't have much space to create / enjoy the ambient glow of the LEDs. That Ceiling will shine more grossly than the Table Top, but the Table Top is still gonna shine.
(...you need a Black Velvet Table Cloth...)

Quote:
See attached photo of my room currently. The image in the picture is 142" diagonal...touching the crown molding and two inches above the table.
The image shown should be 70" tall. If you make a screen that is 66" high, then you can go 3" below the Crown, and 3" above the Table Top. Do that and at least when you have the LED lights dimmed, you will have a equally sized glowing band on all edges.

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Thanks!
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MM,

First of all, happy belated Father's and Grandfather's Day...I hope you enjoyed yourself.

I quoted the dimensions they are giving, but there is obviously some discrepancy. I just ordered it, and it will be here on Wednesday. I will take exact measurements when I get it.

I measured 72" of space between the top of the table and the molding, and yes, the current image is right around 70" tall.

If we leave a 3" gap at top and bottom, that should equate to 66" tall and 117" wide which should be 135" diagonal.

If I can get 135" diagonal with this Cinegrey 3D, I will be very happy.

Frankly, the reflection off the ceiling and table doesn't bother me much.

I'll report back with full Cinegrey dimensions when I get it. Let me know if you have any other questions before then.

Thanks again!
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post #15 of 19 Unread 06-19-2017, 02:19 PM
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Sounds like a doable plan of action. I await your next missive.

And thank you for the Fathers / Grandfathers Day blessing! Had a quiet Day....all my Sons are out of town. So I just grilled up a couple 1.5" thick Prime Rib Steaks and the Wife made up all the Fixins'. It was a feast.

I got 6 GKs now...but my eldest Son and his Wife are expecting.......TRIPLETS!





All Girls.

Bam. Went from 5 Grandsons and 1 Granddaughter to 5 & 4 in one jump.

Come September I might get scarcer around here. Can't type while holding so much new femininity. And hold 'em I will...you betcha!

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Wow! That's a lot going on. Good times for sure. I dated a girl in college who was the youngest of three girls in her family. Her dad really wanted a boy, so they decided to try one more time and wound up with triplet identical twin girls. Ha ha!
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post #17 of 19 Unread 06-19-2017, 05:55 PM
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Wow! That's a lot going on. Good times for sure. I dated a girl in college who was the youngest of three girls in her family. Her dad really wanted a boy, so they decided to try one more time and wound up with triplet identical twin girls. Ha ha!
Same exact thing happened here! (I think?) Two Identical-s and one Fraternal. Both sides of the families fell out!

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Howdy MM,

Ok, I measured the Cinegrey 3D at 121.0" W x 68.25" H which is a little over the advertised 120.0" W x 68.0" H.

I'm not sure how much this will stretch when pulling around the frame, so with those dimensions and losing a little on the wrap around, do you think we can make this screen 66" tall and 117" wide which would be 135" diagonal?
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Same exact thing happened here! (I think?) Two Identical-s and one Fraternal. Both sides of the families fell out!
Hey MM,

Looking forward to hearing back from you. Please see my post above this. Thanks!
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