# Help with Screen Size



## Kekegenkai (May 11, 2021)

Here are my room dimensions












My seating distance I would prefer be 14'-15' for the first row the second row will be on a 12" riser back about 18'-19' from the screen.

The room is pitch black no light what so ever. It will be mostly for watching movies and some TV when we do watch TV / Sports there will be some light (enough to see the guy next to you). As for now https://19216801.onl/ https://routerlogin.uno/ I have no projector selected, but was thinking of going with an Epson 8350. Any thoughts? Here are some numbers I figured from another site.












I believe I will need to add more gain to the screen if I go larger. Thats another concern I have should I do a DYI screen or buy one.


Also wondering what you think of this set up for a mid- level first time HT build speaker audio set up. I'm trying to work in a budget and achieve a really nice 5.1 surround sound. Is a 7.1 worth the extra set up for my room? Here is what I am looking at? Any thoughts would be greatly appreciated.


Polk Audio Monitor 70 Series II Floor standing Loudspeaker.

Polk Audio CS2Series II Center Channel Speaker

Polk Audio Monitor 40 Series II Two-Way Bookshelf Loudspeaker

Onkyo TX-SR609

Do you think I would need a sub for the room? Looking at a Dayton Sub 120.


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## Oleson M.D. (Feb 3, 2010)

Our theater is 24 feet by 20 feet. Seating is 3 rows, each on risers.
Our DIY screen is 155” diagonal.


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## Da Wiz (May 8, 2019)

You are talking about UHD video being your high quality source. Recommended viewing distance to see all the detail in UHD video is 1.5 times the height of the viewing area of the screen. For you to get a screen that size suitable for 14-15 foot viewing distance, you would want a 16:9 screen 16.5 feet wide/198 inches wide. So you have a problem with your layout already... your room isn't 16.5 feet wide. You also have to consider "throw distance"... how far back will the projector be from the screen. And lumens... there's literally NO home cinema projector under $100,000 that will make a satisfying bright HDR image on a 16.5 inch screen. Further... if you use a SUPERWIDE screen, you will likely have to use an acoustically transparent screen because there won't be space for speakers to the sides of the screen. Acoustically transparent screens APPEAR to have similar Gain specs as non-acoustically transparent screens. Most of them say their Gain is 1.0 to 1.2. Unfortunately, NO acoustically transparent screen manufacturer provides ACCURATE Gain numbers for their screens because they would appear to have a "worse" product than everybody else. I typically measure 1.1 gain acoustically transparent screens somewhere in the 0.7 to 0.83 range meaning that you lose 17% to 30% of the light that reaches the screen. So an inexpensive projector with modest light output, say 1800 lumens, wouldn't even be able to produce 10 fL on a 16.5 foot wide screen. People seem to have a MASSIVE FETTISH for HUGE SCREEN SIZE plus DISTANT VIEWING that demands a projector with 8000-10,000 lumens but they only have a budget for 2000 lumens. That's going to be a massively disappointing theater. When I was doing calibrations, I measured an incredible number of theaters as having only 8 fL available on-screen for 100% white. Today, for satisfying UHD/HDR images, you want your projector to deliver 32 fL to the screen. This is the new reality for producing a worthwhile modern home theater. That means if you can afford a 2000 lumen projector, you would need 4 "stacked" projectors to produce images bright enough. 

Epson's first 4K Laser projector was $8000 and only produced 1800 Lumens. If the projection screen was more than about 7 feet wide, the images were just too dim and even at 7 feet wide, a solid screen with 1.0 gain looked too dim. That projector would have needed at least 1.3 gain to look decent on a 7 foot wide screen. Going above 1.3 gain almost universally results in images with hot spots... whatever part of the screen you are paying attention to appears to have a round blob about half the diameter of the height of the screen will appear to be a swarm of mosquitos in front of the image causing it to look unnatural. So there isn't a whole lot you can do with screen gain to get images bright enough... a good portion of the extra light you need to make UHD/HDR look good is going to HAVE to come from the projector. And the larger the screen, the brighter the projector has to be. I would suggest on settling on an 8-9 foot wide screen, solid material and move your seating so the "front" row is 8 feet away. The screen will give you the same viewing angle as a 16.5 foot wide screen you sit 15 feet from. Then there is the consideration of throw distance. Some projectors (Benq is one I recall) have little or no zoom capability on the lens. Placement from an 8-foot wide screen was limited to about 11 feet. When the projector has a wider zoom ratio there is potential for more flexible placement BUT zoom lenses cause loss of light at some zoom settings and less loss of light at other zoom settings... so you have to use caution so you don't lose any of the limited brightness a budget projector can deliver. I have screens that are 8 feet wide and solid and 11 feet wide and acoustically transparent. There aren't any projectors I've used with a lower than 3000 lumens for the factory spec that produced satisfying images on the 11-foot wide acoustically transparent screen. My viewing distance is 8 feet and distance to the L-C-R front speakers is also 8 feet to the main center seat. With the distance from those main 3 speakers being 8 feet, I hear much more DIRECT SOUND from the speakers than I would hear sitting 15 feet from the speakers. At 15 feet there is a HUGE amount of time for reflected sound in the room to be MORE of the sound you hear than the direct sound from the speakers. This makes the SOUND MUCH WORSE and much less localized to specific locations. When the speakers are 8 feet from the listeners, direct sound from each of those speakers arrives at the main seat BEFORE all of the reflected sound energy in the room. You want the direct sound to be more prominent than the reflected sound for best clarity and spatial location. This is a frikkin complicated topic that I just about NEVER see described REALISTICALLY for anybody thinking about this.

Also understand that for $3000-ish, you can purchase a 85-inch diagonal flat screen TV that can produce 100% white at 3000 nits, on screen (about 875 fL). I'm not sure what the price of the Epson model you mentioned is, but if it happens to be their $5000 laser projector... check the lumens... if it is below 2000 lumens, you really need to downgrade your screen size ambitions to around 8 feet wide at most. If it is 2000-2500 lumens, 9 feet might work, but UHD/HDR will be better on the 8-foot screen. And if the lumen spec is 3000-3500, you could get away with 10 feet but again, the 8-foot screen would be better because it would be brighter. It used to be we setup projection systems so 100% white was 12 to 20 fL. That was for standard dynamic range... all the way up to 1080p.

With the advent of UHD HDR content, the general thought is 100% white should now be 32 fL for projection. So the flat screen TV option gets you 885 fL for 100% white, while the projection system can MAYBE do 32 fL for the same measurement. Now, you never see a screen-full of 877 fL white unless somebody made a mistake... because that is WAY WAY too bright, uncomfortably, look-away-from-the-screen bright. The way UHD/HDR works on bright video displays is that almost the entire image is presented between 0% white and 50% white. But on the 875 fL TV, 50% white is set to perhaps 35-40 fL. That's where 100% white was set for 1080p or 720p content. All the remaining light available to the flat panel TV is used to expand the colors that the TV can reproduce. That 875 fL TV will display pretty near 100% of the larger color space defined by the DCI/P3/D65 standard currently used for UHD/HDR content. The projector that produces 32 fL will be setup so that what USED TO BE 100% white at 16 fL nominally and the remaining light capability the projector has from 16.1 FL to 32 fL is used to expand the range of colors the projector can reproduce. Note that the projector has only 16 extra fL to expand the color gamut while the flat screen TV in this example has 830 or so fL that can be used to expand the color gamut for UHD/HDR content. Guess which one looks best while reproducing UHD/HDR content. It is this limited luminance capability of projection that is KILLING PROJECTION. We are already seeing LED screens the size of cinema projection screens. In 10 years, I think at least 50% of the worlds theaters will have direct-view displays without projection. Even if there were projection light sources that could put 875 fL on a projection screen, it would not work because all the reflected light from the screen will bounce around and a lot of it will go back on the screen reducing contrast and clarity of images. So projection relies on the room not being too bright in order for projection to work. UHD/HDR works better the brighter the video display is. Fact of life. You cannot "make" projection as good as direct view displays for UHD/HDR content--it is simply not physically possible. Some of these new LED screens are snap-together modules and the final screen can have FAR MORE resolution than 3840x2160 (UHD) even if the source is no higher than 4K, the images on these so-called modular screens will be as good as or better than what people can achieve at home. 

Lots to think about here--no matter WHAT anybody else says, what I laid out here is pretty much the reality of the situation. I'm an optical systems engineer for 34 years and professional home theater product reviewer since 1995, and I calibrated home theater systems for 5 years. I review multiple projectors and flat-screen TVs every year and the demise of projection has been coming since 2015 or so. The cost of the cinema-size direct view screens is still a bit challenging. But like everything else, the cost of the tech gets lower every year. At some point, the cost of direct view LED screens will become manageable for theaters to install in in all auditoriums at multi-plexes. Movie theaters have a hard time now because enthusiasts own large TVs that produce better images than theaters can currently produce. Theaters don't like that... one of their "draws" is that they give you a viewing experience you can't have at home but if your $2500 home TV produces better looking movies... why pay $20 to see it in a theater unless just being with a human audience is worth that cost to you.

I'm reviewing a $25,000 projector right now. Setup a 75-inch flat screen next to it, and play the same content on both screens and the projection setup (oh, this 75-inch TV on hand was only $1800 full retail. The projected image is BIGGER (on an 8-foot wide screen). But the COLOR and vibrancy and clarity of the images was better on the 75-inch TV and if I move the 75-inch TV close enough to have a 45 degree viewing angle, just like the projection screen, the images on the 75-inch TV appear to be the same size as they are on the movie screen... sitting closer to make the images appear larger is just as visually enveloping as viewing a larger screen from a farther distance.


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## freud16g (Jan 13, 2022)

Here is a calculator that I used years ago. I was not the author but it may be helpful to you and fun to play around with. Check it out here: Home Theater Calculator: Viewing Distance, Screen Size – Carlton Bale .com
Jay


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