Buildind a wall screen

[vsavka]

I would like to build a wall screen for a projector that I am going to buy. Now I really don't know how to do this but, the projector will be about 12-13 feet away from the wall, and siting position is about 16-17 feet away. Now on the wall i have about 5 feet in height and 7 feet in length.

Now the question is, what are my limits to build this screen. I really dont understand the whole concept of 4:3 and 16:9. If i make it 4:3, will i still be able to watch widescreen movies? now when people talk about their screens being 96", does that mean diagonally?

So if my wall area is only 5x7, what would be my diagonal measurements, and height and width as well. And if you don't mind telling me how to calculate one.

thanks, val

 

[majorloser]

Let's start with the basics first.

What projector do you own or plan on buying?
Will it be a ceiling mounted?
How's the ambient light in the room? Controllable?

 

[majorloser]

I really dont understand the whole concept of 4:3 and 16:9. If i make it 4:3, will i still be able to watch widescreen movies? now when people talk about their screens being 96", does that mean diagonally?

To help answer some of your questions in the mean time.

A 4:3 format means that for every 4 units of width (inches) the image is 3 units in height. Also known as 1.33:1 format

A 16:9 format means that for every 16 units of width (inches) the image is 9 units high. Also known as 1.78:1 format. (16:9 is your standard HD format.)

When somebody speaks of their screen size they refer to the diagonal measurement and the format ratio i.e.: 97" 16:9 screen.

 

[vsavka]

sorry, its goning to be a ceiling mounted projector. I am not sure which one yet, but within $1k limit. The light is controlable as I only have one window in the basement living room. That can be closed by blinds

 

[majorloser]

Projectors and Screens

Let's start with the projector. Since you have about $1K to spend check out the Optoma H70. http://www.optomausa.com/Product_detail.asp?productsubcat=3&productcategory=Home+Theater&product_id=294

It was reviewed recently by Audioholics: http://forums.audioholics.com/forums/showthread.php?t=26341

I own an Optoma H78DC3 with a Stewart 100" diag screen. LOVE IT!

The Optoma HD70 is a 720P native projector (16:9). If your front screen area is approx 7' wide and 5' high you can fit a 96" to about 105" diag 16x9 screen in this space and remain at your desired 12' to 13' projection distance. Remember the distance is from the front of the lens to the surface of the screen. Any offset of the screen from the wall or the mounting point of the projector vs. the front of the lens comes into the calcs. Optoma has a screen calculator on their site to help: http://www.optomausa.com/distancecalculator.asp

The Optoma H70 doesn't have a lot of zoom capability so mounting location is very important.

With a 16:9 (1.78:1) screen in the 96" to 105" range you'll end up with a screen that is approx 4' high. Most people say you should sit about 3 to 4 time the screen height from the screen for HD material. That would put your anticipated seating distance in the right range at 16 feet.

 

[majorloser]

More Useless Info

Images are available in four basic formats.

NTSC Video 4:3 / 1.33:1
Diagonal x .8 = width
Width x .75 = Height

High Definition (HDTV) 16:9 / 1.78:1
Diagonal x .87275 = width
Width x .5625 = height

Widescreen Movie 1.85:1
Diagonal / 1.135 = width
Width / 1.85 = height

Cinemascope Widescreen 2.35:1
Diagonal / 2.55 = height
Width x 2.35 = Width

(Thanks to Stewart Filmscreen for the formulas )

It all falls back to that basic geometry for a right triangle we all forgot in high school.
(a^2) + (b^2) = (c^2)
a= height
b= width
c= diagonal (hypotenuse)

 

[vsavka]

so if i create a 96" diagonal screen, will i still be able to watch 4:3 format on it? as well as HD and widescreen? will those formats fit on the 96" diagonal screen?

 

[majorloser]

The projector will display a 4:3 image in the center of the screen. This way you can still watch standard definition TV. If you have a 96" 16:9 screen a widescreen image is 84" wide and 48" high. When a SD (4:3) image is projected on the same screen the image is 64" wide and 48" high. This will be equivalent to a 80" diagonal 4:3 screen.

With DVD's you're going to want to watch anamophic widescreen DVD's whenever possible. They are formatted to fit the 16:9 screen and give you the whole film image, not pan & scan.

 

[BMXTRIX]

This is what you will see when watching most movies on that screen:
http://www.avintegrated.com/aspect_ratios

Don't be confused - the screen doesn't magically change size to fit all the different formats of films that have been shot over the years - so you have to pick one and live with it. Screen masking can be added later (black velvet covered wooden boards) to give you proper framing if you want.

Since your projector will be 16:9 (it should be) then your screen should be 16:9 as well. 4:3 television (regular old TV) will have black bars on the sides. All HDTV will fill it perfectly, and 2.35 films will leave black bars above/below the image.

With a 15+ foot viewing distance you actually want to go about as large as possible with the screen size without killing the brightness of the projector. I would shoot for 100" minimum. Realistically - your seating distance asks for about a 133" diagonal! Your budget and size restrictions don't allow for that though.

Don't forget sound as that is NOT built into the projector or room and must be addressed separately. As is all the cabling you will need and source components, etc.

 

[vsavka]

thanks for advice. Again im very limited with size. Just to clarify one more time, when u say 130" diagonal, that is in 16:9 format right? Also in height and width how much is that(130" diagonally)? I am really bad in math sorry.

as long as i can watch tv format on the 16:9 then it should be ok. I wouldnt mind the bars on the sides.

 

[majorloser]

thanks for advice. Again im very limited with size. Just to clarify one more time, when u say 130" diagonal, that is in 16:9 format right? Also in height and width how much is that(130" diagonally)? I am really bad in math sorry.

as long as i can watch tv format on the 16:9 then it should be ok. I wouldnt mind the bars on the sides.

A 133" 16:9 screen will be 65" high and 116" wide. About 5' 5" tall and 9' 8" wide. And that's not counting a black frame to absorb overscan.

Keep in mind that the bigger the screen, the worse standard definition TV will look. Upconverting standard television signal can only do so much. You REALLY get an appreciation for how good HDTV looks when you see the comparison.

It would help us out if you could post a sketch of the room you plan on using.

 

[gmichael]

16:9 Screen- 41"H x 73"W = 84" Diagonal
16:9 Screen- 49"H X 87"W = 100" Diagonal
16:9 Screen- 52"H x 92"W = 106" Diagonal
16:9 Screen- 59"H x 104"W = 119" Diagonal
16:9 Screen- 71"H x 122"W = 135" Diagonal
16:9 Screen- 75"H x 130"W = 150" Diagonal

 

[BMXTRIX]

All numbers that I will give typically are based on people buying a 16:9 projector and matching it to a 16:9 screen. If you look at the world of home theater and video it is ALL about 16:9 - so I use that as the standard.

Generally speaking, I don't recommend that you watch much regular televsion on a projector. Some digital TV stuff can look so-so, and HDTV will look absolutely phenomenal. But, regular television will tend to not look great. Depending on your opinion it may look 'bad', but this is all opinion. I have used my projector at one time as my ONLY television and watched regular TV on it all the time. Black bars on the side... and I guess 'grainy' would be the term I would use to describe it. Not horrible, not even 'bad', but quite clearly subpar. The jump in quality that DVD and HDTV gives is tremendous. But, it was still very viewable and enjoyable.

To make a car analogy - SDTV is like a Toyota Camry. Nothing exciting, not the most powerful or most refined - and might have a few minor hiccups. It doesn't match up to the refined Mercedes (DVD) or really nice Porche (HDTV), but it is readily available and always reliable.

 

[vsavka]

when u say diagonal widescreen size, does that INCLUDE the black bars or no/?

also if i keep my screen size 106" diagonally, does that mean that my 4:3 ratio is only gonna be 52"Hx68"W ?

thats kinda small

 

[BMXTRIX]

when u say diagonal widescreen size, does that INCLUDE the black bars or no/?

also if i keep my screen size 106" diagonally, does that mean that my 4:3 ratio is only gonna be 52"Hx68"W ?

thats kinda small

52x68 - Yes, that's correct.

No - that is NOT kind of small. That's about a 7 foot diagonal! But this is THE KEY TO REMEMBER:

Regular Digital TV is the WORST form of television. How big do you think you can make it before it is unwatchable? This is the crux of everything. Your smallest screen size should be with the worst video. SDTV - regular cable or satellite TV. The biggest size should be used for the best signals. DVD is a huge step up on regular TV and HDTV is the gold standard - and is what you are optomizing your screen and viewing for.

Quite often I have seen people go with a 4:3 screen setup and then a year later they are repurchasing a bunch of gear to switch to 16:9. You see, with a 4:3 setup, regular TV is 'BIG' and so-so looking. Then they put on HDTV and the image is SMALLER! They have this phenomenally pristine image - and it is smaller than their so-so image... That just doesnt' make sense at all.

Hope the explanation makes sense.

 

[vsavka]

thanks for explanation. I really dont care that much of the quality as i am not an expert to tell the difference, also it is gonna be used only like once or twice a week. But hey thanks alot, i mostly understand it now.

a question that hasnt been answered is, does the 106" diagonal widescreen INCLUDE the black bars? or without

 

[majorloser]

thanks for explanation. I really dont care that much of the quality as i am not an expert to tell the difference, also it is gonna be used only like once or twice a week. But hey thanks alot, i mostly understand it now.

a question that hasnt been answered is, does the 106" diagonal widescreen INCLUDE the black bars? or without

The 106" diagonal 16:9 screen would include the "black bars" along the sides when viewing 4:3 standard definition material. That's still a big image in 4:3.

It's when you view a widescreen movie or HDTV that it'll blow your socks off!

 

[BMXTRIX]

a question that hasnt been answered is, does the 106" diagonal widescreen INCLUDE the black bars? or without

I don't have a calculator to give you exact numbers but...

16:9 106" diagonal screen will give you:

106" diagonal image with HDTV material (16:9) no black bars

106" diagonal (approx) with widescreen 1.85:1 DVDs (not cinemascope!) no black bars

84" (approx) diagonal with regular TV (4:3) black bars on the left and right

92" (approx) diagonal with cinemascope DVDs (2.35:1) with black bars above and below.

Hope that helps clear things up. If not, I will do some Photoshop work to lay it out more clearly.