Optimum size of the TV screen is directly related to the distance available for viewing – but there are other factors that must be considered.
Viewing distance: It 'only a matter of personal taste?
Sit too close to the TV to the big screen and be able to see the image build-up structure – scanning lines or pixels forming the image – in order to distract the attention and enjoy your home theater experience. But sitaway and lost the effect.
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 soon you will realize that everything is a matter of personal preference – some sat in the back. Others would jump to the front row, because they prefer a bigger picture and wider viewing angle, while others would simply choose randomly located halfway between these twoExtremes.
The truth is that there are no scientific rules her. This does not mean that there are guidelines that you should follow when planning an acquisition 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 the home theater would occupy a 30-degree field of view – the horizontal plane – for the public.Alternatively, the ideal distance for watching TV should be the width of the screen has an angle of 30 degrees to the upright position.
These were 30-degree viewing angle seems to have adopted widely regarded as the standard for home theater and movies.
The directive SMPTE is also in line with the THX certification that the standards recommend that the rear row of seats must have at least one angle of 26 degrees, and lawyers, while an optimalViewing angle of 36 degrees.
It is believed that, within these limits is a better perspective of the viewer is lost in the action movie itself.
Vision System limitations:
It 'also the question of TV viewing distance visual acuity. This is not the optimum viewing distance – but refers to the maximum distance to go display some details about the image is lost.
Technically speaking, visual acuity is a measure of Eye power of spatial resolution and indicates the size of the angle to the smallest detail that a person can solve the visual system. A person with 20/20 (or 6 / 6 when expressed in meters capable of solving) normal vision of a spatial model from a viewpoint of a minute which is the angle arc 1/60th degree of self in the eyes when viewed at 20 meters away. In other words, a normal person with 20/20 vision can identify an object with a height of 1.76 millimeters to 20 feet is capable of doing.
Regarding theDistance Vision> TV, this is the frontier, some of the viewing window will no longer be solved by the vision system viewer.
So how to explain it in practice?
Some rules-of-thumb to help put into practice the guidelines above. These rules for viewing distance to screen width, not in diagonal screen and then apply for both 4:3 and 16:9 display formats.
A general rule for TV viewingDistance based on the SMPTE and visual acuity is the discipline that the nearest TV viewing distance between you and your big screen TV should be about twice the width of the screen is limited (to be precise 1.87 x screen width for a angle circular circumference of 30 degrees), while the longer distance, not more than five times the width of the screen.
This rule of thumb should give you an approximation good enough for the distance of TV viewing. It is not necessaryrepresent the ideal home theater viewing distance, but the limits within which the TV viewing distance should theoretically from the area of trouble.
In other words, more than twice the width of the size and image scanning lines, points and other video artifacts will be visible too intrusive – that spoil the distractions that you will be film. Move further away than 5 times the width of the screen and the vision system will no longer Being able to solve all the image details.
But …
It 'also important to recognize that these maximum and minimum viewing distances, in the light of the definition of the video signal should be considered.
A fully resolved high definition TV (1080i, 1920×1080) supports a greater distance than standard analog TV viewing. Thus, while twice the screen width would be the ideal TV for only a HDTV display, it would be a bit ' too close to standard –> TV, in the case, three times the width of the screen may be the best choice.
Five times the screen width of the maximum visibility, while more than adequate for a standard analog TV picture is a bit 'too far for a support person to the smallest detail of a picture HDTV – see three to four times the width screen is a practical limit to the maximum distance of view in the case of HDTV.
These rules-of-thumb work best with big screenTV size in the range of 42 inches and above.
When it comes to regulating the use of standard size definition analog TVs in the home theater, ie up to 36 "/ 40" diagonal, the optimum viewing distance is between 8 feet and 12 feet. Televisions smaller by 36 inches Aren 't big enough to have qualified for home theater use, the small screen size is not the desired effect on the viewer.
Vertical viewing angle and height of the screen:
For optimal viewing,the viewer's eyes should be level with the center of the screen.
Maximum vertical viewing angle: In the home theater set-up in case this is not possible, the SMPTE guidelines suggest that the maximum vertical angle should be measured by the highest part of the image projected on the eye level when seated on the seat Front row can not be half of 35 degrees.
This is not the optimal viewing angle, but the border is the subject of the beholderincreased neck strain.
The maximum vertical angle is always in the front row, because these are measured with the far corner.
Minimum angle: Although it does not seem to be a specific SMPTE or THX guidelines in this area, but studies have shown that when the screen size takes less than 15 degrees vertical field of view, the viewer that the small picture is displayed.
Practical Considerations:
In a typical home theater-upYou no longer need or the maximum angle vertical to worry about, not even beyond the minimum requirements for a cinema effective vertical angle.
If one of the recommended TV viewing distance of twice the width of the screen to keep (as detailed at the top of the Directive SMPTE 30-degree horizontal field of view), would automatically satisfy the minimum angle. The reason is that there is a fixed relationship betweenThe height and width of the screen to your home theater screen aspect ratio of 16:9 or 4:3.
And more than this would be in a typical home theater setup, it is very difficult, the maximum vertical angle from which have undergone a major effort of the neck is exceeded.
Considering that most home theater rooms are approximately 10 feet (3m) is high, the resulting vertical viewing angles and within the normal limit of 35 degrees in the detailed guidelines SMPTE- Everything you need to do is to stay just under twice the width of the screen guidelines for the removal of the beholder.
