By applying fairly stringent criteria in order to approximate a quasi worst case scenario then you would want a display with a true diagonal screen size that is no larger than approximately (0.61×[Viewing Distance] or) 88 inches for a 1920×1080p display and (0.43×[Viewing Distance] or) 62 inches for a 1280×720p display IF you want to greatly minimize the potential for noticeable picture structure at a viewing distance of 144 inches.
The following details a few of the primary factors used to establish the aforementioned criteria. It is assumed that: (a.) that the observer has good visual acuity; (b.) all viewing will be performed under ideal viewing conditions, i.e. in a dark room with no ambient light that can produce veiling glare or reduce the perceived image contrast; (c.) the display is capable of very good motion resolution (or Moving Picture Response Time,) i.e. motion blurring reduces the effective video resolution; (d.) the picture settings have been properly adjusted–or optimized–to produce maximum image quality (especially image contrast); and (e.) the observer will be viewing a precision resolution test pattern consisting of alternating black and white lines (having the appropriate contrast modulation) that correspond to the native resolution of the display. Of course those who comprise the average TV viewing public rarely if ever sit around viewing test patterns on their televisions. So when it comes to real-world applications you will find that you can actually sit closer or get away with using a slightly larger screen size if desired. Nevertheless, all things considered I recommend that you err on the side of caution and limit your choice of screen size to the maximum diagonal screen size results derived from the simple formulae above. In other words, at a viewing distance of 12 feet you currently have no practical screen size limitation when it comes to common direct-view HDTV’s.
By the way, the chart published as part of the recommended screen size information on the Flat Panel TV Info Website is currently labeled very poorly and the information therein is strictly applicable to 1080p displays only. Furthermore, the information posted on that particular Webpage lacks a proper list of citations or references, which should cause anyone to be circumspect. You will find better information on the topic of recommended screen sizes and viewing distances by using the resources that I’ve listed below.
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What would be the right size TV to put in my room?
https://answersrip.com/question/index?qid=20090629205810AA8I3P9
Carlton Bale
– Home Theater Calculator: Viewing Distance, Screen Size
http://www.carltonbale.com/home-theater/home-theater-calculator/
– Screen Size vs. Viewing Distance vs. Resolution
http://www.carltonbale.com/2006/11/1080p-does-matter/
Chris Collins’ “My Home Theater” Website
– Vertical Viewing Angle
http://www.myhometheater.homestead.com/Verticalviewing.html
– Viewing Distance Calculator
http://www.myhometheater.homestead.com/viewingdistancecalculator.html
Erik Garci
– Pixels Per Degree Calculator
http://home.roadrunner.com/~res18h39/calculator.htm
– Isometric Diagram for THX Cinema Audience Viewing Angles
http://home.roadrunner.com/~res18h39/thxscope.gif
HD Guru Gary Merson
– Lechner Distance: The Number You Need to Know Before Buying an HDTV
http://hdguru.com/lechner-distance-the-number-you-need-to-know-before-buying-an-hdtv
– [PDF] HD Guru Viewing Distance Chart
http://hdguru.com/wp-content/uploads/2006/11/hdtv_distance_chart.pdf
Practical Home Theater Guide Systems Reviews and Home Theater Design
– Screen Size versus Optimum Viewing Distance
http://www.practical-home-theater-guide.com/Tv-viewing-distance.html
High Definition 1080p TV: Why You Should Be Concerned
http://www.hometheaterhifi.com/volume_14_1/feature-article-1080p-3-2007-part-1.html
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THX
– THX Home Theater Display Setup
http://www.thx.com/home/setup/display.html
– THX Certified Cinema Design - Screen Placement
http://www.thx.com/cinema/builtTHX/screen.html
– [PDF] Lucasfilm THX Theatre Alignment Program (“TAP”) Guidelines
http://www.thx.com/library/pdf/guidelines.pdf
[PDF] Screen Size: The Impact on Picture & Sound
http://www.dolby.com/uploadedFiles/English_(US)/Professional/Technical_Library/Technologies/Dolby_Spectral_Recording_(SR)/19_screensize.pdf
[tig] viewing distances
http://tig.colorist.org/pipermail/tig/2004-September/005887.html
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[PDF] Cowan, M. “Image Quality for Home Theatre”
http://www.etconsult.com/papers/Image%20Quality%20for%20Home%20Theatre%20Matt%20Cowan.pdf
Society of Motion Picture and Theater Engineers (SMPTE)
– Westerink, J. H. D. M. and J. A. J. Roufs. “Subjective Image Quality as a Function of Viewing Distance, Resolution, and Picture Size.” February 1989. SMPTE J., Vol. 98, p. 113
http://www.google.com/search?hl=en&q=Joyce+H.+D.+M.+Westerink+site%3Asmpte.org
– Recommended Practice RP 166-1995, Critical Viewing Conditions for Evaluation of Color Television Pictures (Archived 2004)
http://store.smpte.org/product-p/rp%200166-1995.htm
– SMPTE Engineering Guideline EG 18-1994, Design of Effective Cine Theaters, March 1994, (Withdrawn in 2003)