[Maurice Shapiro]

Is there a formula that one can use to establish the optimum viewing distance from seating to the screen?

[Bob McElfresh]

Yes, this Viewing Distance Calculator can be used.

I prefer the THX technique of trying to get a 23 degree view of the screen.

[Maurice Shapiro]

Thank you. This is just the information I wanted.

I appreciate your quick response.

Regards, Maurice

[ChrisWiggles]

Keep in mind that different display technologies and resolutions will support different satisfactory viewing angles. For instance, a high-end CRT projection system you could sit very close to, while a low-end low-resolution LCD would have horrible screen door, and you would want to sit much further away for a pleasing image.

[GeorgeAB]

The THX minimum viewing angle is recommended for the most distant back row in a commercial movie theater. Their maximum viewing angle for film is 45 degrees. Be careful of using recommendations for film exhibition. Film resolution is much finer than the best HDTV in the home.

The ATSC worked from a 30 degree viewing angle in designing the HDTV system for a typical maximum of 1920 x 1080 resolution. Their consensus was that most viewers would not be able to see pixels at that resolution and the gains in using wider images were not substantial for acheiving a sense of immersion in the action.

Most HDTV front projection rigs in homes are using 1280 x 720 chips. I have found in my experience that a 30 degree viewing angle still reveals 720p pixel structure from many LCD projectors. The brightest portions of a projected image will reveal pixel definition first.

My eyesight tends to be a little better than many of my acquaintences. I don't recommend any greater than a 30 degree viewing angle for 720p. That works out to a formula of screen width x 1.87, or seating distance divided by 1.87.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

[John S]

I sort of go with Bob's idea....

I try to set people up, so they get a similar equivelent field of view as from the back of a pay movie theater.

I even have some rectangles of different sized cardboard to illustrate it to them in their proposed setting.

[GeorgeAB]

I "sort of go with" the Society of Motion Picture and Television Engineers (SMPTE), the International Organization for Standardization (ISO), the Advanced Television System Committee (ATSC), and similar motion picture standards and practices governing organizations. These people are the experts in the field of human factors and optimum viewing conditions for motion imaging. Motion picture production, post production, duplication and exhibition all follow industry standards proven effective over decades of research, theory and practice.

All this work was not undertaken to vaunt some misguided opinion of what will work for one or a few individuals. The purpose of instituting and maintaining standards is purely to preserve the integrity of the original art and maximise enjoyment for the intended viewer. Without standards there can be no reliable repeatability of the intent of the program producer. Motion picture industry standards and practices are the foundation of every successful system installation. Any deviation in system design should only be for very specific reasons and an understanding of the potential consequences carefully weighed and justified. Otherwise the full enjoyment of the art will be diminished unnecessarily.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

[John S]

I have to admit, it is rare I get to work on dedicated theaters. Most of what I do is help people do the best they can in their living room and family room environments.


I can only imagine some of the installs your company has done GeorgeAB.....

[GeorgeAB]

Any type of system for exhibition of movies will offer its best performance when designed with an understanding of the system rules as the foundation. This applies to any type of room or equipment. There will always be compromises that need to be made in multi-purpose rooms. With an understanding of the system rules, it's much easier to minimize the consequences to system performance.

I can't overemphasize the importance of one element of the system that few really understand well enough. That element is the viewer. Human visual system characteristics are typically the least understood performance factor in entertainment system design today. Screen size and location, seating distance, display type, lighting, room decor, all have an impact upon the viewer's perception of the image.

One of my most common challenges is working with clients who want a screen that's too large for the primary seating location. Most consumers work from a basis of what they experience in commercial theaters or see in magazines. They really have no concept that there are scientific reasons for both film and video system design. Their pre-conceived notions of what they want have no basis in science. Usually, all they know is what they've experienced. What they think they "like" has no real connection to image fidelity. Even other industry professionals they have spoken to have very little understanding of imaging science, display standards and human factors.

Far too many home theater sales people are eager to sell a larger, more expensive screen, when a customer asks for it. When it's fundamentally wrong for the planned seating distance, the customer should be educated as to why, and what the specific consequences will be if such a decision is made. The customer is not always right! Every customer has a right to be ignorantly or wilfully wrong, but it's the professional's job to let their client know what's at stake when deviating from the system rules. Home theater design professionals who have little formal understanding of imaging science are pretty much "flying blind" when attempting to help a customer make a design or buying decision.

The Imaging Science Foundation, among others, has been teaching these principles for about a decade now. Many people in the home entertainment industry think the ISF classes are just for people who want to become display calibrators and never get the training. The majority of the information in the training deals with the fundamentals of how our video system works, the various display devices available today, what types of displays are best for various uses, human perceptual characteristics, and what constitutes an accurate picture. Then there are others in the classes so focused on just wanting to make a living calibrating TVs that they fail to adequately absorb much of the other information.

Just knowing a lot about equipment is not enough. Successful home theater design is a synergy of many disciplines. Every discipline has fundamental principles that must be mastered as a foundation before growth and expertise are achieved. Anyone who attempts to design custom home theaters without a formal understanding of the pertinant SMPTE standards and practices is just guessing. These fundamental principles are applicable to every electronic display installation, not just dedicated theaters.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

[John S]

Interesting philosphy on it. I don't fully subscribe to it though. Customer preferences still have to come first.

Your basic numbers you posted seem pretty much in line with the so called guesses most of us use and have come up with as well as the industry guidlines in general.
Your spiel is impressive though for sure.

I'd still love to see some of your companies work sometime.

[ChrisWiggles]

What he's saying is what I said briefly up above. There is such a thing as sitting too close to the screen, especially with many of todays fixed pixel displays. The proper viewing angle, or SW ratio away will vary depending on the display type and resolution. As I mentioned above, the displays supporting the closest viewing are high-end CRT projection, and 1080p LCOS displays, which can comfortably support 1x screen width viewing with proper sources. At these distances, the source material can be a problem, I would only suggest sitting this close with very clean HD sources. DVD is too noisy this close, and not enough detail. But the capabilities of the display chain itself support this close.

With 720DLP, I would recommend nearly twice as far away, close to 2x screen widths for elimination of screen door and the best 3-dimensionality, and perhaps a little further still for LCD.

Now, keep in mind that these recommendations are from a more video purist perspective, so the average user may not be so spoiled by high end displays that screen door is normal and not objectionable to them. This is why I believe in helping a user understand the high-end purist perspective, let them see it, and then decide whether they prefer that kind of imaging quality, or are willing to remain with their previous expectations. After all, it is a system designed for someone else's preferences, not our own. As a CRTer myself, I know full well that while I value the incredible imaging of such a device, it is a very rare person for whom a CRT FP is at all appropriate.