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wackychimp

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Trying to figure out how large of a screen I can fit. I've tried the online calculators, and they give a good idea of where to place my projector but not how to place the screen. In my specific case, the geometry is a little weird becasue it's a finished attic and the roofline "cuts off the corners".

Here's a photo (ignore my mocked up fake skylights - those will come later).

The flat part of the ceiling is 7' 9" if you couldn't read it. I'd love to get a 120" diagonal screen but a friend who's into home theater thinks it will be too low to the ground and not look good. I can ceiling mount the Epson 3020 (doesn't have lens shift) anywhere between 11-15ft. back. So throw distance shouldn't be a problem.

My question is this: how do I figure out how much lower the screen will have to be due to the angled ceilings? Also, with no lens shift in the projector, the bottom of the projector needs to align with the top of my screen, correct?

The numbers:
• 120" screen would be 110" actual width (104" with 3" border) and 65" in actual height.
• Flat ceiling is 93" across.
• I have a difference of 17" or 8.5" on each side.

How much lower off the "flat ceiling" will I need to go to get that 110" (actual) width?

Any thoughts or suggestions appreciated. Or do I just need to look at a 110" diagonal screen?

MississippiMan

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Hey Wackychimp!

Quote:

Trying to figure out how large of a screen I can fit. I've tried the online calculators, and they give a good idea of where to place my projector but not how to place the screen. In my specific case, the geometry is a little weird because it's a finished attic and the roofline "cuts off the corners".

Here's a photo (ignore my mocked up fake skylights - those will come later).

The flat part of the ceiling is 7' 9" if you couldn't read it. I'd love to get a 120" diagonal screen but a friend who's into home theater thinks it will be too low to the ground and not look good. I can ceiling mount the Epson 3020 (doesn't have lens shift) anywhere between 11-15ft. back. So throw distance shouldn't be a problem.

My question is this: how do I figure out how much lower the screen will have to be due to the angled ceilings? Also, with no lens shift in the projector, the bottom of the projector needs to align with the top of my screen, correct?

The numbers:
• 120" screen would be 110" actual width (104" with 3" border) and 65" in actual height.
• Flat ceiling is 93" across.
• I have a difference of 17" or 8.5" on each side.

How much lower off the "flat ceiling" will I need to go to get that 110" (actual) width?

Any thoughts or suggestions appreciated. Or do I just need to look at a 110" diagonal screen?

A 110" diagonal screen still needs 96" width....so based on what I see, a drop of a minimum of 8" is needed (Ceiling to Top of Lens )

........and you'll need to lose the idea of having those projected Sky-lights to at least 6' back from the Screen wall. Or cover them up with a movable Black-Out Shade affair...which is crazy considering you gotta spend the bucks to get'tem installed.

I see your best design as being a painted "Shadow Box" 5' out and covering the Slopes and Ceiling. Just paint it 4x darker a shade of the existing Brown. This will offset the extremely close proximity of the edges of the screen to the ceiling and Sloped sides.

(...I can show you some examples if you care to see them....)

Even so, that will place the lowest edge of the 3020's casing at under 7'. It's that circumstance that puts your "Screen -size" choices to a minimum.

"My Kingdom for a PJ w/Lens Shift!"

As far as having a "Low Down" screen, it's all about who needs to view it from where. If you want "view-ability" over the heads of anyone sitting in front of the screen, 110"s located as suggested is your only choice.

Unless you want to have the PJ hanging below 7'. You also can use the keystone feature...but that is a last resort.....but something to consider if you want 120" placed lower on that wall.

As stated, if the only important viewers are to be those sitting, then you can easily do 120" diagonal, and employ the Keystone feature. But even then you still want to hang the PJ as low as you absolutely can so you can minimize it's use

A screen that is 24" off the Floor but sized rightly is going to immerse you within it's influence.

Now then.....whose advice do you really want to depend on as far as the obvious need for an ambient light screen that will allow you to have those desired Skylights blazin' beyond the suggested 6' area? Beyond all the rhetoric....AVS DIY Screens has a wealth of info and help, along with DIY Screen applications proven by far more successful projects done under extreme conditions than anywhere else......bar none.

Like this:

http://www.avsforum.com/t/1432177/painting-onto-a-106-tab-tensioned-screen-with-silver-fire-v2-5-4-0

........unless your going to cover up that Window for the duration. I would.

wackychimp

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Thanks!

I was actually planning to cover the window and hang a fixed screen. I just worry too much about a retractable screen being too "fickle".

The skylights are intended to be faux skylights with a fiber optic star field in them. This way it's always twilight in there. I'm not putting in real skylights so I'll be in control of the lighting. (This image was from my "dreaming" stage where I was trying to come up with the "perfect" HT room. Now that I'm beginning the building stage, I've got to be more practical.
)

Yeah, I know that a projector with lens shift would be much preferred in a case like this, but didn't want to pay the extra \$1100 for the 5020. I'll have to "make-do" with this one.

Typically, fixing the display with keystone correction is a last resort, right?

MississippiMan

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
Quote:

Thanks!

I was actually planning to cover the window and hang a fixed screen. I just worry too much about a retractable screen being too "fickle".

The skylights are intended to be faux skylights with a fiber optic star field in them. This way it's always twilight in there. I'm not putting in real skylights so I'll be in control of the lighting. (This image was from my "dreaming" stage where I was trying to come up with the "perfect" HT room. Now that I'm beginning the building stage, I've got to be more practical.
)

Yeah, I know that a projector with lens shift would be much preferred in a case like this, but didn't want to pay the extra \$1100 for the 5020. I'll have to "make-do" with this one.

Typically, fixing the display with keystone correction is a last resort, right?

Well, in most every case. But in a situation like yours it's almost mandatory.

At least there is a way to easily find your best positioning.

1. Hang the PJ at the lowest possible location....say the bottom of the PJ 7' off the floor, using a Chief RPA PJ Dedicated mount (...ya just gotta! ) and a Peerless Round Ceiling Plate.

Epson 6020 done as such....;

The Pipe is PVC w/Male Couplings. Inexpensive and easy to switch out. And when a longer Drop is required, the ability to easily pass / hide all the Cable / 110 ac lines makes for a splended installation.

Try a assembled length such as 16", which will have the top of the lens at 20" off the Ceiling. (7' 2" off the Floor) Level unit front to back & side to side and plumb the unit perpendicular to the wall / screen.

Shoot the Blue Start Up screen onto that wall. Zoom until the corners of the image contact the side walls.

Using the Chief's tilt adjustment, angle the unit until your upper corners have a minimum of 6" from the Slopes.

Hopefully it would not require much of an adjustment to do this.

Now using Keystone, square the image. If all you must do is bump the Vertical Keystone value 2-3 points....that is in no way going to be detrimental.

So now, you'll know how much higher you can go, and use an appropriately shortened Pipe / Coupling assembly.

........or if you simply gotta, add a few more inches and increase the screen size even further while further reducing the extent of Keystone correction needed.

.......or you just might find the first try lets you NOT use keystone at all. That would be a Perfect World scenario. But hope springs....

Whatever the choice, now we / you mark off the edges of the perimeter of the "projected" Screen area, check the wall for surface defects and repair / sand / prime the enclosed area, and spray Silver Fire 2.5 3.0 to complete what will be an ideal solution for use with the 3020.

Bar none.
Well OK....RS-MaxxMudd or RS-MM-LL either would also work splendidly, the latter best of all if your truly going to keep lighting issues under your firm guidance and control. It has enough ability to enhance perceived contrast and combat modest ambient light, while retaining a lot of gain doing so that you can run the 3020 on low lamp all the time, and always get a dynamic image with great Blacks.

The above is just the start of the help you can count on during your proposed Theater. I hope to see you progress....with success.

JustinRT

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I modeled your screen wall in Sketchup. I pushed the screen all the way up, so the corners of the frame are touching the ceiling. Let me know if you'd like to see any other screen sizes.

Edit - The picture uploaded to AVS might be too small to read the dimensions, so I also uploaded it to ImageShack:

MississippiMan

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Nice Model.

If the Top of the screen is moved down to be just over the Top Edge of the Window Frame...with the Window Casing removed so the Screen assembly can lay flush against the wall, then the screens slightly lower appearance will be much more balanced, and the difference between having a 33" space between the Floor and Screen and one approx 28" will be no issue as far as viewing.

But it might be expecting too much for him to aspire to a 138" diagonal (120" x 72" btw.) unless he places the 3020 at 13' -7" In any case, your screen measurements, including Trim, don't add up to being a precise 16:9 format. Unless your working some magic with variable screen trim widths.

If Wackychimp can provide you / us with an exact measurement of how far the bottom of the window casing is off the floor, as well as the total height of same, the available screen size as relates to wall placement can be effectively narrowed down.

But all that taken into consideration, he does need to mount the PJ at the suggested distance, and attempt to plaster a test image on the wall so as to really have an exact location (PJ Drop - height and distance) and screen size down pat.

JustinRT

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
Quote:

Nice Model.

[...] In any case, your screen measurements, including Trim, don't add up to being a precise 16:9 format. Unless your working some magic with variable screen trim widths.

If Wackychimp can provide you / us with an exact measurement of how far the bottom of the window casing is off the floor, as well as the total height of same, the available screen size as relates to wall placement can be effectively narrowed down.

But all that taken into consideration, he does need to mount the PJ at the suggested distance, and attempt to plaster a test image on the wall so as to really have an exact location (PJ Drop - height and distance) and screen size down pat.

Thanks.

I noticed it wasn't 16:9 too, but those were the dimensions he gave in the first post, so I figured that's what he wanted. It's quick and easy to model these things out in Sketchup, so I'm happy to make any changes you or Wacky would like to see.

MississippiMan

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OK......a lounging Sophia Vergara inset within that Frame.

Quicker!

JustinRT

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
Quote:

OK......a lounging Sophia Vergara inset within that Frame.

Quicker!

I apologize for taking so long. I started searching for Sofía Vergara photos, and... I don't know; I guess time just got away from me.

MississippiMan

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Totally understandable. Any exercise in creative modeling requires a careful and studious approach.

BTW, THAT's a excellent use of One's Tool to it's best advantage.

wackychimp

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LOL! I'm scrapping the whole project and going with a 138" Sophia Vargara.

Thanks for the mockup in Sketchup. That looks great!

Somebody asked about seating: I've only got 1 row - 2 couches in a "V" with an aisle in between.

My numbers in the first post may have been off a little. I was posting them from memory. Whatever a 120" screen works out to be.

After doing a test, I'm leaning towards a 133" diagonal. I projected a 138" to be the max size the wall could take. I don't have a ceiling mount yet but that PVC one looks great! My test was done with boxes on a table at 15' back and about 6' off the ground. As far as the ceiling goes, I can mount the projector just about anywhere. With the 8'10" ceiling, I'm not worried about how far I'd have to drop it down.

Here's the link to the projector calc for my PJ: http://www.projectorcentral.com/Epson-PowerLite_Home_Cinema_3020-projection-calculator-pro.htm

I'm figuring a 14' throw, 133" diagonal with a 0.8 screen gain (Lunar grey screen I'm looking at is 0.85 gain). I'm right in the "green areas". Did I do that right?

I didn't get the dimensions you asked for on the window & I'm at work now. I'll try to get them this weekend.

Here are my tests (Fan is a goner. Just haven't taken it down yet.):

MississippiMan

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OK....now I'm beginning to "get" where the handle "WackyChimp" hails from.

You would, in my opinion, be in serious error to consider any screen below 1.0 gain just to satisfy the potential to watch content in ambient light, as well as help improve the inherent black levels of the 3020.

And why you'd want to spend what amounts to considerably (...ridiculously actually...) more than the difference you'd have outlaid for a 5020 , a PJ with measurably better lumen & contrast specs and feature set, on a over-priced Mfg Screen, is a totally foreign concept to me, as well as running counter to the entire premise that such screens can be had via DIY-ism, and do a better job than Mfg offerings...both in a cost to performance aspect as well as being totally customizable to your exact needs. This is the DIY Screens Forum. Not the SI-Fan Club.

Time to get real...and down to brass tacks here. To get the performance you need, you want a Screen with 1.2 gain, and contrast enhancement potential, that will allow you to both run in Low lamp to achieve the 3020's best Black levels, and to calibrate the PJ to an optimal state so the Colors and Whites are still dynamic and punchy.

Ain't no 0.85 gain gonna provide that sort of results.......ever.

Now to that effect.........the 133" diagonal, set a little lower that you show, (...Top corners 4" down from the Slopes...) and at 14' Throw onto 1.2 gain would provide 23 foot lambert in Normal lamp mode.....and 16 fls in Low Lamp...and should you opt to view a 3D presentation...you'd still maintain 14 fls in 3D. Also, as the Epson's lamp ages, you'd have Normal lamp in reserve to re-ramp up brightness for a spell.

Sheesh! At 0.85 the best you'd ever manage on Full lamp output is 15 fls, and everything goes downhill from there.

It's a proven fact...Big is better...but just the same, Big & Dim only amounts to "Big & Useless"

wackychimp

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This is good to know. I was under the impression that the gray screens were preferable when watching in partially lighted rooms. I'd say that we'll be spending about 40% of the time watching sports with the lights on (dimmed, but on). Other 60% for traditional "movie nights". So in your opinion, I need a white screen?

I'm no SI fan specifically, and I probably posted in the wrong forum. I'd started out trying to get advice on how to figure out how big of a screen I needed and now that's morphed from the original intent.

On this project I've had to come to terms with myself that while I WANT to be a DIY-er, I'm just not going to get it done on any reasonable time line. I'm working with a friend who does installs and he's running the wires, doing electrical, setting up the speakers and mounting everything, so I'm getting the screen through him. Got all of the equipment (projector, receiver, etc.) online for much cheaper. We started out looking at the Black Diamond and moved down in price from there.

Screen hasn't been ordered yet, which is why I'm trying to figure out everything this week.

Thanks for all of your suggestions.

MississippiMan

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No...I never said white. I just said your "Gray" had to be over 1.0 gain.

No White surface is going to satisfy your needs all around. Nope, here's where you choose whose advice to take and which Screen app to use.

At your size screen, any +gain Gray Mfg Screen that fills the bill would be your biggest expense of all, if not actually more than all combined. A SI-BD would be a bad choice....too many issues, and a DNP would cost enough to qualify for a New car loan.

Straight up, I can suggest to you a simple, Roll-able mix (RS-MaxxMudd LL) that will carry you through this issue. That won't help out much if your insistent on getting a Mfg Screen though. Also, not at all sure what you consider a reasonable time frame but if you simply say "I'm going for it" I'm sure you could have the Screen up and ready to get pasted with an image before this time next week.

It's really a matter of if you really want to save money and keep the performance levels you need and want. Really....at 133" diagonal your making the bed you must crawl into. As to if you wind up sleeping on expensive Straw, or affordable Satin Sheets.......that's gonna be your decision to make. If your stuck with only using someone who only can provide a Mfg solution, then that is a shame. (...but I have run into such before....)

The necessary procrastination while all this conversing has been going on might of forced you to make a wrong decision. Honestly....this all was / is a simple do.......it just needs to get done. There's a big difference taking advice from those who really can only make suggestions, and advice from those who know pretty much exactly what will work best in almost any given situation. DIY-wise especially.

That last statement might dredge up some hatemongers, but in truth, it's only your situation I'm really concerned about. Not how others might feel / react. In the end, your own evaluation will either dismiss such naysayers, or validate their opinions. Myself....I know exactly how it would / should turn out. Here's hoping you can find out.

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