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best projector screen size

1853 Views 29 Replies 13 Participants Last post by chirpie, Jan 24, 2006

v1rtu0s1ty

Discussion Starter · Dec 24, 2005

I have decided the room dimension to be 14'x23'x9' or 15'x26'x9' for my home theater. First for viewing position is 12 feet away from the projector screen. If these are the values, what is the best projector screen width size or diagonal size? What should be the height of the lower part of the screen from the floor?

Thanks guys!

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stevennoland

· #2 · Dec 24, 2005

How close you can sit depends on your projector. A CRT projector doesn't suffer from the dreaded SDE (Screen Door Effect), so you can either sit closer or have a bigger screen. With most DLP, LCD or derivative, the SDE comes into effect the closer you sit. I would go with the general rule of 1.5 times the width of you screen. Example: 110" diagonal equals 91.2" approx wide. (COS 34 degrees times 110") times 1.5 equals 136.8" or 11.4 feet. With the new 1080p projectors comming right around the corner, being able to sit closer with the same size screen shouldn't ba a problem.

v1rtu0s1ty

Discussion Starter · #3 · Dec 25, 2005

Hi. Thanks for the answer. But I think, you didn't get my question or my question was a bit confusing. I already have decided with the dimension of the dedicated home theater room and that is 14 or 15 feet wide and 23 to 26 feet long. If assuming I have 14 feet wide, it's not nice to have a screen 13 feet wide. It's too big. Or 4 ft wide which is too small.

Like what I said earlier, the first row chair is going to be 12 ft away from the big screen and the second row might be 16 or 17 ft away from the screen. There must be some ideal formula or program that calculates the ideal screen size based on the room dimension. However, I have only found a program which tells if the dimension of the room is ideal. It does not recommend a screen size.

ronaldk988

· #4 · Dec 25, 2005

I think Steven does answer your question. You want to know how big a screen to put in a room that you have the dimensions for. Well, your width of the scren should be about 1.5 times the distance the seating is to the screen.

How High should the screen be? I have heard the lower third of the screen should be at eye level, so have someone measure how high you sit, that measurement should be 1.3 up from the bottom of the screen.

Ron

Allen

· #5 · Dec 25, 2005

Quote:

Originally Posted by ronaldk988
I think Steven does answer your question. You want to know how big a screen to put in a room that you have the dimensions for. Well, your width of the scren should be about 1.5 times the distance the seating is to the screen.

How High should the screen be? I have heard the lower third of the screen should be at eye level, so have someone measure how high you sit, that measurement should be 1.3 up from the bottom of the screen.

Ron

Based on paragraph 1 of the quoted text, applying the formula correctly means that the seating distance is 1.5 times the screen width, so for a given seating distance of 12 feet that means 1.5x = 12 where x = screen width, therefore you would use 8' wide for your screen if you use that formula, not 1.5 times seating distance.

For paragraph 2 above, the screen height (assuming 16x9) for an 8 ft wide screen would be approx 54". If you used the lower third formula, you eyes should be about 18" above the bottom of the screen. Using 36" for eye height when seated, that would yield 36-18= screen bottom about 18" above floor level of first row of seating.

I don't vouch for the validity of the formulas, though I don't challenge them either. I am merely applying them properly.

Allen

(With way too much time on my hands as I temporarily duck a Christmas eve gathering)

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v1rtu0s1ty

Discussion Starter · #6 · Dec 25, 2005

do you guys know any 1080p projectors that are below $2000? I was looking at the Optoma before but I don't have any idea right now if it supports 1080p.

PatrickGSR94

· #7 · Dec 25, 2005

That's not going to happen for awhile, methinks. The top 5 1080p projectors on projectorcentral.com range in price from $10,000 to $20,000, with one of them having a price tag of a whopping $250,000.

I think your best bet would be to probably go for a native 720p projector, like the Panny AE-900U, which is somewhere in the $3K range.

v1rtu0s1ty

Discussion Starter · #8 · Dec 25, 2005

I'm assuming that 34 degrees is a standard value. Since my viewing position is 12 ft away, and screen width is 8 ft or 96 inches, then diagonal is roughly close to 116 inches(9.6ft) and 65 inches(5.4ft) vertically or the rectangle as 8' x 5.4'.

So if this is the case, is 8'x5.4' screen too much for a 23'x14'x9' room? What do you think guys?

Thanks for the formula

v1rtu0s1ty

Discussion Starter · #9 · Dec 25, 2005

Quote:

Originally Posted by PatrickGSR94
That's not going to happen for awhile, methinks. The top 5 1080p projectors on projectorcentral.com range in price from $10,000 to $20,000, with one of them having a price tag of a whopping $250,000.

I think your best bet would be to probably go for a native 720p projector, like the Panny AE-900U, which is somewhere in the $3K range.

How will a 1080i program such as PBS.ORG's HDTV program like NOVA look on a 720p projector?

PatrickGSR94

· #10 · Dec 25, 2005

I'm sure it would look great. I can't tell any difference between 720p and 1080i on my Sony 30" CRT HDTV.

But also consider that interlaced images only have half of the vertical lines displayed at any given instant, while progressive displays all lines at all times. So with 1080i only 540 lines are displayed at a time, while 720p displays 720 lines at all times.

v1rtu0s1ty

Discussion Starter · #11 · Dec 25, 2005

going back to my question, is 8'x5.4' screen too much for a 23'x14'x9' room? What do you think guys?

v1rtu0s1ty

Discussion Starter · #12 · Dec 25, 2005

hey guys, looking at this calculator( http://www.myhometheater.homestead.c...alculator.html ), my previous value for the diagonal, 116 inches(9.6ft), is incorrect.

It's telling me that it should have a diagonal of 110 inches or 9.2 ft for a final rectangular dimension of 96 inches x 61.5 inches.

So this is the correct dimension right?

EDIT: You know what guys, the 34 degrees is confusing me. I'm getting a different value. What degrees should I use in the screen so I can get the proper hypotenuse of an 8ft wide screen?

Gerry S

· #13 · Dec 25, 2005

a 110" diagonal screen is 96" x 54", assuming a 16:9 aspect ratio.

In other words, it is 16 units long and 9 units high. Just use ratios to get the height or width, given one of the two. For example:

9/16 = 54/x

cross multiply:

9x = 16*54 (or 864)

divide by 9:

x = 96

If you know the length and height, just use pythagorean theorem to get the hypotenuse, or diagonal measurment.

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jamin

· #14 · Dec 25, 2005

110 inch diag yields 8 ft x 4.5 ft 16:9 screen

The diagonal measure is the square root of the sum of the square of the height and the square of the width.

jamin

· #15 · Dec 25, 2005

Oops - cross post, Gerry S beat me to it.

poolboyclay

· #16 · Dec 25, 2005

Quote:

Originally Posted by v1rtu0s1ty
going back to my question, is 8'x5.4' screen too much for a 23'x14'x9' room? What do you think guys?

That screen size will be fine. You definately want to go wider on the room size. You'll need good speaker seperation.

Clay

smithb

· #17 · Dec 25, 2005

A reply from a different perspective is to try and gauge it yourself by looking at a real screen with hopefully a projector similar to what you think you might purchase. The width of your room is more then adequate to get a fairly large screen so the real question is what you prefer. I've read of people using anywhere from 1.0 to 3.0 times the screen width as a proper seating distance with screens measured diagonally anywhere from 80" to 160". Probably the most common diagonal measurements are between 90" and 110".

Screen door effect is one factor. Another is projector light output vs. screen size and ambient light issues. Yet another is motion in full screen pans which can make some feel uneasy.

While there is suggested guidance as mentioned above there is really no true gauge of what you are susceptible to or what would work best for you other then to test it out for yourself. Find a place that has a theater setup or a friend with the same, try and watch something for a period of time testing out different distances and you will have your answer.

I bought a projector before getting a screen and just viewed on a painted wall for a while which allowed us to test out different sizes ahead of time. We had issues with motion, especially with MTV like filming techniques (e.g., Bourne Supremacy, Man of Fire). Therefore, we went with a 92" screen and we sit about 15' back. I also prefer a punchy image so there is no problem with my Sharp 10K lighting up that size screen, even with 1200 hours on it (of course I also have a Silverstar screen).

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Head Shot

· #18 · Dec 25, 2005

As for the lower screen border height from the floor, it all depends if the second row will be on a riser or not. If no riser, the screen must correspondingly be higher off the ground to compensate for the viewing blockage caused by the front row. How much higher depends on the first row seat with viewer profile. In this case it would not be out of the norm to have the bottom screen level about 36"-48" off the ground.

chs4

· #19 · Dec 26, 2005

My room dimensions are similar to the OP at 23'L x 17'W x 9'H. I have two rows of seating: first row at about 12' and second row about 18'. (my "sweet spot" is in the first row) My second row is on a 13-1/2"H riser. I'm using a Panny AE700 firing onto a 110"D DIY screen. Bottom of the screen is about 28" above the floor.

IMO there is no "perfect" screen size for a given room. I took into account the various calculators, formulas, SMPTE recommendations, etc. which got me into the ballpark of where I wanted to be. I then went the DIY route temporarily so that I could see for myself if I chose the right size for me, and I'm glad I did. When I purchase a "real" screen it will definately be in the 120"D range, which is slightly larger than the "recommended" size, but it is what I'll be comfortable with.

For DVD and HD sources SDE is non-existant from my seating distance and picture quality is excellent. Upconverted digital OTA locals are also very watchable from the first row. Everything else (i.e. SD locals and compressed satellite channels) is a crapshoot. While I don't watch much SD at all in the HT, when I was testing it out I had to sit in the back row or it was simply miserable quality-wise.

As others have already mentioned, a lot will depend on your projector and choice of source material. My advice is not to sweat the screen size too much at this point. Get your room set up, decide on a projector and then do some testing to see what works best for you.

Formulas be damned!

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v1rtu0s1ty

Discussion Starter · #20 · Dec 26, 2005

Just came home from a christmas party

Great inputs guys! Definitely, I'm taking your advice to not spend too much time on calculating screensize. I read the review of Panny AE900 and I like it very much. The reason I like the Panny AE900 is that, the Linux based pvr I built is currently driving my mitsubishi ws48313 crt based hdtv via the Air2PC hdtv card and nvidia 6600GT video card. And I'm thinking that it will work with it. However, it's beyond my budget.

I'm trying to stay as close to $1500-$1700 budget but I don't know if I can find a projector similiar to the features AE900 and those features are HDTV support, no SDE even when projected at 8' wide and being viewed 12 ft away.

I guess by that time I move to the new house next year(july), prices might be lower.

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