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Discussion Starter · #1 ·
Hi All,


I am beginning construction on my Dedicated Home theater. My finished Room Size will Be 20' x 16' x 8'-6" ceiling. I am completely new to the DLP projectors and my last Projector was an Ekei Powerhouse 1 LCD Projector.


I want to do a 10 foot wide 16:9 screen Approx 140" Diagonal. I want To see what HD DLP projectors will work for this size screen at about 15' - 18' from the Screen. The projector will be hung on the ceiling.


I am trying to stay under $5k for the projector and get the best picture possible.

Also any suggestions on fixed Wall Screens will help too!


Any suggestions will greatly help!


Thanks

Ruben
 

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Are you sure you want a 10' wide screen?


That is 56.25 sqft of screen - assume you shoot for an average 12ftL - that requires a 900 lumens lamp with a 1.0 gain screen.


Only the Infocus SP72xx will do that.


Of course you can do a higher gain screen - but you need to be concerned with your viewing/throw angles to see if it will work.
 

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The Optoma 79 will place your projector between 15 and 18 feet and it will cost you less than 5K. In regards to gain, I would go with a 1.3 white gain screen assuming you have total light control. The 1.3 gain screen would be for example the Stewart Studiotek 130 or the Dalite

Cinema Vision.


Some people are big fans of 1.0 gain screens and they do work in certain environments, but unless you have weird viewing angles, a 1.3 gain will work very well for you. If you want an even brighter image, then I would go with something like the Vutec Silverstar which although is rated at 6.0 gain, its more in the 3 - 4 neigborhood. It would be more sensitive in the viewing angel, but many people use this screen and really love it
 

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Daniel


900/1.3 =692 - so a 1.3gain would only work in H79 brite lamp mode which burns up quicker.


So I think you would want to go a bit brighter screen than that! SilverStar does not come that big. A DaLite High Power might work for 1.5gain with a ceiling mount, or use Dalite Pearlescent 1.5 gain if you can stand the sparkles. Viewing angle needs checked out on both of those. Keep in mind with the wider screen you want to check the viewing angles to the edges as well to avoid hot spotting.


I only use 1.0gain screen for the reference calculation - then it is easy to figure out what you really need from there.


From WSR...


"I measured the light output of the projector using my D65 gray scale calibration with the White Peaking turned off. In the high brightness lamp mode, the projector produced 775 lumens, which is equivalent to 35.4 footLamberts (fL) from my 85.3-inch wide, 16:9, 1.3 gain Stewart Studiotek 130 screen. In the low lamp mode, the projector produced 578 lumens, which is equivalent to 26.4 fL from my screen. The full-field (on-off) contrast ratio measured about 2900:1."
 

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Discussion Starter · #5 ·
How about BenQ 8700? Will that work?
 

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You have to research out reviews of the HT verified lumens and do the math - anything can work given enough gain and limitations on viewing angle.


I doubt the BenQ8700 is brighter than the Optoma though. I would guess more like 400 lumens based on past BenQ's. For that Draper M2500 material would work well - again if the viewing angle works out with no dead seats or hot spots.
 

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Discussion Starter · #7 ·
I have No windows in the Dedicated Theater room. It will be completely Black in the Mid of Day. The Color Scheme and Layout will be Similar to Art Sonneborn's new theater.


The Room will be Accoustically Treated as well.


The Optoma H79 is 1000 ANSI Lumens

The BenQ PE8700 is 1000 ANSI Lumens

The Toshiba MT800 is 1100 ANSI Lumens
 

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Do a 9' wide DaLite Cinema Vision 1.3 gain screen, use an H79, change your bulb early if it seems too dim and you'll be happy like I am! Can't wait to go home and watch a movie with the wife! Perhaps we'll sip a chocolate martini and watch Chocolate'.................
 

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SandMan


Those are marketing specs that have nothing to do with how you will use the projectors in their movie modes. They are at least 2x off - aside from the Toshiba which is an Infocus clone.


So in reality it is more like


The Optoma H79 is 600 HT Lumens

The BenQ PE8700 is 400 HT Lumens

The Toshiba MT800 is 900 HT Lumens


This is why you cannot ignore the right screen gain.
 

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Discussion Starter · #10 ·
I completely should of mentioned that I don't have to have the projector that far away from the screen (ie. 15 - 18 feet) if its gonna kill the brightness. I can also put the Projector closer to the screen if that helps in brightness. I just figured, the further away from the screen the bigger the picture would be. But Realistically, I don't Mind putting the Projector 2 feet to 20 feet from the screen. Can a Projector do a 10 foot screen at at 5 feet away?


It's a new construction, so I can run the wires anywhere while the ceiling is open.


THanks for all the great input guys!


Ruben
 

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Throws are typically 2x screenwidth - but each differerent projector is on the short or long side of that.. 140" diag is unusually large. You certainly can find a screen with gain to work with any of the projectors - the question you need to address is the gain viewing angle an issue for your seating - you need screen samples for that.


The other consideration is seating distance - a 10' wide screen should have seats no closer than 13'4".
 

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Quote:
Originally Posted by SandmanX
I completely should of mentioned that I don't have to have the projector that far away from the screen (ie. 15 - 18 feet) if its gonna kill the brightness. I can also put the Projector closer to the screen if that helps in brightness. I just figured, the further away from the screen the bigger the picture would be. But Realistically, I don't Mind putting the Projector 2 feet to 20 feet from the screen. Can a Projector do a 10 foot screen at at 5 feet away?


It's a new construction, so I can run the wires anywhere while the ceiling is open.


THanks for all the great input guys!


Ruben
Whatever projector you pick out, it will only be able to project that 140" image within a certain range, also known as the throw distance. And that probably will be in the 15-18 ft range that you mentioned. So you won't be able to mount the projector closer than the minimum throw distance for any particular image size in order to gain brightness (that's your 10 foot image at 5 feet away example). So if your image size requirement is fixed, then so is your projector mounting distance. And for the sake of this discussion, your available lumens with the resulting ftL image is fixed as well (and only goes down from there with age).


This should narrow down your choice of projectors rather quickly. The only other variable under your control is screen gain in terms of image brightness (ftL). Just pull out a calculator and calculate the lumens you need in order to produce what you want (12ftL for movie brightness or 36+ftL for TV screen brightness). Then compare this lumen number with actual real world measured lumens of the projectors you are considering. Should be pretty clear cut.
 

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Discussion Starter · #13 ·
Well according to the Projection Calculator at Projector Central, The Optoma H79 Requires to be mounted 21.5 Feet from the Screen to give you a 138" Diagonal Screen.


The BenQ PE8700 Requires 16.6' from the Screen to d a 138" Diagonal screen and will be bright enough with a 1.3 Screen Gain.


The Toshiba MT800 Requires 20.6 feet from the Screen to do a 138" diagonal screen and will be bright enough with a 1.0 gain screen.


So this Kind of narrows my search down to the BenQ PE8700. I was just using these 3 projectors for comparison because they seem to be the top 3 highly recommended projectors at ProjectorCentral.


Is There any other projectors I may want to consider? inFocus?
 

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sandmanx, I suggest you do research by not going to projector central. Go to the actual manufacturers websites and get as much info as you can. There have been posts in the past that have found projectorcentral to have misinformation.
 

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SandmanX...


Do yourself a favor and download the spec sheets for each of these projectors directly from the manufacturers websites. You should be able to find the "throw ratio" for each projector pretty easily. This will be expressed as a range that is defined by each projector's zoom range. Fit your image size (probably the image width) into the equation to find the range of throw distance.


Projector Central's calculator is odd. I think the numbers you have quoted are the MAXIMUM throw distances. In other words, this is the furthest distance away that you will be able to mount the projector to obtain your desired image size. For your purposes, you should also familiarize yourself with the MINIMUM throw distance for each of these projectors. For example, I have an InFocus 7210 (which I believe is similar to the MT800). I am projecting a 133" diagonal. I could have the projector mounted as close as 16 feet or as far back as 20 feet for the same image size. So for your 138-140" diagonal, it should be somewhere in that range. And then people have opinions on whether you should mount at the wide end or the tele end of the zoom range. Brightness of the picture should be the same to our eyes.


So, you really owe it to yourself when you are thinking about dropping $$$ on one of these babies to get your information directly from the source. And get as much as you can. If you go to the InFocus site, there are throw calculators, screen calculators, schematics for dimensions of the projector....so you can have everything measured out. Every manufacturer should have this info in some form. When it comes to the actual installation, sure there is some wiggle room...but it helps tremendously to have a fairy detailed account of what you need in mind. So keep working through it and don't be afraid to keep bouncing your ideas off your family here at AVS. Having just worked through a lot of this for myself, I have to say that it's been a wondrous education...but what a gratifying experience and end result! And the people here are great! Good luck!
 

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SandMan


Please do not use the PJC ftL calculator! They use the marketing specs for lumens - and may only derate it for the low power lamp mode.


Most projectors are at least 50% off their marketing specs in HT Mode (the specs are in their brightest mode which is usually distorted greyscale and colors). Then lamps themselves drop 50% over their life.


Only Infocus and Runco are providing realistic numbers - for the rest you must search on trustworthy HT reviews. And for HT lumens you cannot trust PJC reviews either - they are woefully inconsistent and unrealistic.



The projector numbers I provided above are probably correct - but you need to derate them for lamp fade a bit. Increasing the lumens required to 16ftL will do that.



jwsteng,


The manufacturers site will not have the HT lumens specs other than Infocus - they will only have the marketing specs. But they usually will link to the good HT reviews.
 

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SandmanX,


I don't understand your seating arrangement. Will your primary seating be in the back row at 18' or the front row at 15'? When the ATSC designed the standards for HDTV they determined that a 1920 horizontal pixel structure would not be visible for the average viewer at a 30 degree viewing angle. That equates to a seating distance of approximately 18' for a 10' wide screen. Your planned projector will only provide 1280 horizontal pixels! Have you spent time in front of a 720p projector to determine what your personal viewing distance should be?


A person's visual acuity can vary from the theoretical average used by engineers for industry standards. I invited a client to my demo theater so he could verify what his actual viewing distance would need to be. He wanted an Optoma H79 with DarkChip 3. His eyesight was not as good as mine and could sit 2' closer than I would. My optimum seating distance for 720p DarkChip 3 is close to the 1.8 multiplier for a 30 degree viewing angle. His ended up at 1.64 times screen width. He was happy to get a wider screen.


You may prefer quantity over quality when viewing a projected image. Many people do. However, if image fidelity is a primary concern, it's a good idea to spend the time needed in front of a similar projector before you settle on screen size. Just stand at varying distances from the screen until you can no longer detect pixels in the brightest portions of the picture. Then measure the viewing distance in inches and divide by the screen width in inches. That will give you your personal viewing distance calculator figure. Decide where your primary seating will be, measure to the screen wall and divide that distance in inches by your calculator figure. That will result in the screen width.


If you have others in your household that will be using the home theater as much as you, and they have better eyesight, you may want to use them as your reference. It's nice to have a big, panoramic image when viewing movies. However, we all know what sky is supposed to look like. My sky doesn't have texture. That's distracting for me and it takes the realism out of the movie viewing experience.


Regarding screen brightness, be careful when referencing film vs. video viewing standards. Film standards are for a dark viewing environment. Our human visual system is adaptive. The SMPTE film standard for screening rooms is 12 ftL. As our eyesight adapts to a dark environment, we become more sensitive to the bright portions of a projected image. A low MEASURED light level will be PERCEIVED as much brighter.


Video standards are for viewing environments with some ambient lighting. We can tolerate brighter images in a lit environment. Professional direct view CRT video monitors are calibrated to 30 ftL, but used in environments with ambient lighting. Even large screens can induce eyestrain if the image is bright enough in a dark room.


Our human visual system has limited contrast. We do much better at resolving shadow detail in darker environments. As brightness is increased, we lose our ability to detect detail and color in darker portions of the image. A great example of how this works is to sit across from another person in a room, away from a window, during daylight hours. Then, have that person sit in a chair between your point of view and a window. You will notice that, with the bright window behind them, it's much harder to make out details in their face. It's certainly possible to have TOO bright of an image when viewing in a dark theater, as contrast increases.


It's always best when designing a home theater to start from a foundation based upon principles of imaging science, display standards and human factors research. There's room for accommodating individual viewer characteristics, such as visual acuity and taste in decor, but sticking close to the system rules will preserve image fidelity and the program producer's original intent. If you don't find image fidelity of particular importance, then the consequences of deviating from the standards doesn't matter much in your case.


Some people would rather make system design decisions based upon what they think they "like." That's perfectly legitimate for them but they may end up realizing the consequences later on, especially after they settle in and use the system over time. Sometimes it takes living with the equipment a while before folks start to notice the details.


Anecdotal experiences, individual opinion and intuition are not reliable imaging system design tools. Imaging industry standards are well researched, proven over decades and designed to preserve quality and consistency. A knowledge of equipment specifications is not enough. How will the image produced by the system be perceived by the viewer? The room and the viewer must also be understood as vital components in system design. Unfortunately, few home theater professionals, and even fewer non-professionals, have a firm grasp of human perceptual factors when specifying system requirements.


When considering where to mount the projector, it's important to understand a few things. Lenses have a "sweet spot" at their center. The farther out you go from the center, the less optical quality will be realized. Focus is less precise and chromatic aberations begin to show up. The best location for projectors with zoom lenses is at the farthest point from the screen, if optical precision is top priority. This will keep the image closest to the lens's sweet spot. I don't prefer projectors with lens shift for this reason. Any lens shift moves the image away from the center of the lens. Besides, those projectors usually require that the center of the lens be no higher than the top of the screen, when they're mounted on the ceiling.


Projectors with a "projection offset" can be mounted higher off of the floor. A recent example was an InFocus 7210 I specified for a client. He was able to mount it about 8" higher than another model he was considering. Since he was planning a hush box, and his back row was elevated, this was a major advantage.


Best regards and beautiful pictures,

G. Alan Brown, President

CinemaQuest, Inc.


"Advancing the art and science of electronic imaging"
 

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Sandmanx,


With regards to accoustically treating your room, I just went through this with my CEDIA intaller and was told NOT to do it untill an audio system was picked out and calibrated even then it is not recommended. You can do more damage to your sound with accoustical panels than with just sheetrock and paint. I have heard of people that did treat their rooms and then got standing sound waves from their sub and could not get rid of it until they removed the panels. Always look and listen before you by additional room treatments. My room sounds great and it saved me thousands on something I didn't need after listening to my equipment in my room.
 

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Quote:
Originally Posted by krasmuzik
The manufacturers site will not have the HT lumens specs other than Infocus - they will only have the marketing specs. But they usually will link to the good HT reviews.
Absolutely, Kras! I guess I was referring to info about throw, image offset, etc... The manufacturer's website usually is good for this. Lumens and contrast ratio are probably the most inaccurate numbers given by manufacturers for whatever reason. For this type of information, I try to glean pearls from people here like you who have the luxury of comparing projectors side by side and doing measurements. Good HT reviews are also valuable for absolute measurements, but it's relative performance that is most noteworthy.


Static information like throw ratio and image offset which I think are vitally important to planning an installation are usually easily obtained from manufacturer literature. But I have seen Projector Central to be inaccurate with this info as well.
 

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jwsteng


Offset is often hard to find - and not a consistent measure. But it is important to know - generally lens shift projectors are placed within the screen, lens offset projectors above. How much should be found in a manufacturers calculator.
 
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