TV Viewing Distance and Screen Placement in the Home Theater

The optimum TV screen size is directly related to the available viewing distance - but there are other factors as well that must be considered.

Viewing distance: Is it just a matter of personal taste?

Sit too close to the big screen TV and you will be able to see the image build-up structure - scanning lines or pixels forming the image - so distracting your attention and enjoy your home theater experience. But sitting too far away, andthe effect is lost.

There are different opinions about the best way to determine the optimum TV viewing distance for a specific screen size. Just go to the movies and you will soon realize that everything is a matter of personal preference - some would sit at the back. Others would jump to the front row, as they prefer the larger screen and a larger perspective, while others would simply choose randomly located somewhere between these two extremes.

The truthis that there is no scientific rules her. This does not mean that there are no guidelines that you should follow when planning a purchase or a big screen would-be home theater room.

SMPTE Recommendations and the THX certification standards:

The Society of Motion Picture and Television Engineers (SMPTE) recommends that the screen size for home theater use should occupy a 30 degree field of view - the horizontal plan - for the audience. Alternatively, the ideal TV canViewing distance should be such that the screen width takes an angle of 30 degrees to the straight position.

These have been 30-degree viewing angle seems to have adopted widely regarded as the standard in home theater and film.

The SMPTE directive is also in line with the THX certification that the standards recommend that the rear row of seats should have at least a 26 degree angle, and advocates, while an optimal viewing angle of 36 degrees.

It isbelieved that within these limits is a better perspective of the viewer get lost in the action movie itself.

Vision System limitations:

It is also the question of TV viewing distance on visual acuity. This does not represent the optimum viewing distance - but it refers to go to the maximum viewing distance of a few details about the image is lost.

Technically, the visual acuity is a measure of the eye and shows the spatial resolutionangular size of the smallest detail that can solve a person visual system. A person with 20/20 (or 6 / 6 when expressed in meters can solve) normal vision of a spatial pattern from a perspective of one minute arc angle ie 1/60th degree of self to the eye when viewed at 20 feet away. In other words, a person with normal 20/20 Vision is capable of identifying an object with a height of 1.76mm at 20 feet is capable of.

In the television sector distances, these represent the numberon some of the display window will no longer be resolved by the viewer vision system.

So how does all this translate into practice?

A few rules-of-thumb to help put into practice, the above-mentioned guidelines. These rules for viewing distance to screen width, not diagonally across the screen and therefore apply to both 4:3 and 16:9 display formats.

A general rule for TV viewing distance of the SMPTE and visual acuity is based guidelines is thatthe nearest TV viewing distance between you and your big screen TV should be limited, approximately twice the screen width (more precise 1.87 x screen width for a circular circumferential angle of 30 degrees), while the furthest distance, no more than five times the width of your screen.

This rule of thumb should give you a fairly good approximation for your TV viewing distance. It is not necessarily the perfect home theater viewing distance, but the limits within which your TVViewing distance should theoretically from the trouble zone.

In other words, more than twice the width of the size and the image scan lines, points and other video artifacts will be visible too intrusive - which spoil distractions that you will be movies. They continue to move away than 5 times the screen width and your vision system will no longer be able to resolve all the details of the image.

But ...

It is also important to recognize,that these maximum and minimum viewing distances should be seen in the light of the video signal definition.

A fully resolved high-definition TV (1080i, 1920x1080) supports a closer viewing distance than standard analog TV. Thus, while twice the screen width would be the ideal TV away just for an HDTV display, it would be a little too close for standard TV, in the case, three times the screen width would be the better choice.

Even the five times the screenWidth than the maximum visibility, while more than adequate for a standard analog TV picture is a bit too far away for a support person to the smallest detail of an HDTV picture - a three to four times the screen width is shown a practical limit for the maximum viewing distance in the case of HDTV.

These rules-of-thumb work best with large TV screen size in the range 42-inch or more.

If it is analogous to the use of regular size standard definitionTVs in the home theater, ie up to 36 "/ 40" diagonal, the optimum viewing distance is between 8 feet and 12 feet. TVs smaller than 36-inches are not big enough to have qualified for home theater use, its smaller screen size is not the desired effect on the viewer.

Vertical viewing angle and screen height:

For optimal viewing of the viewer's eyes should be level with the center of the screen.

Maximum vertical viewing angle: In the homeTheater setups where this is not possible to beat the SMPTE guidelines, the maximum vertical angle to the uppermost part of the projected image on the seated eye height from the front row middle seat can be measured not more than 35 degrees.

This charge does not represent the optimum viewing angle, but the boundary that are subject to the viewer, an increased neck.

This maximum vertical angle limit is always the extreme measure from the front row, because these areAngle.

Minimum angle: Even if it does not appear to be a specific SMPTE or THX guidelines in this regard, but studies have shown that when the screen size takes less than 15 degrees vertical field of view, the viewer than the small picture is displayed.

Practical considerations:

In a typical home theater set-up, you do not need to make really about neither the maximum vertical angle cares, not even on the minimum requirements for vertical viewing angleeffective cinema experience.

If one of the recommended TV viewing distance of twice the screen width to keep (as set forth in detail the top of the SMPTE Directive of 30 degrees horizontal field of view), you would automatically meet the minimum angle. The reason is that there is a fixed relation between screen height and width to your home theater screen aspect ratio of either 16:9 or 4:3.

And even more: in a typical homeTheater setup, it would be very difficult, the maximum vertical angle from which you are subject to an increased neck strain cross.

Considering that most home theater rooms are approximately 10 feet (3m) is high, the resulting vertical viewing angles well within the normal limit of 35 degrees in the SMPTE guidelines detailed - everything you need to do is just within twice the screen width guideline for your eyes to stay apart.