It is apparent that 1080p is the lowest resolution to fall within the recommended seating distance range. Any resolution less than 1080p is not detailed enough if you are sitting the proper distance from the screen. For me and many people with large projection screens, 1080p is the minimum resolution you’d want.

In fact, you could probably even benefit from 1440p. If you haven’t heard of 1440p, you will. Here’s on Audioholics.com. It is part of the HDMI 1.3 spec, along with 48-bit colour depth, and will probably surface for the public in 2009 or so. You’ll partially be able to see the benefits of 1440p at the THX Max Recommended viewing distance and the resolution benefits will be fully apparent if you are just a little closer. I’ve read of plans for resolutions reaching 2160p but I don’t see any benefit; you’d have to sit too darn close to the screen to notice any improvement. If you sit too close, you can’t see the far edges of the screen.

If you are a videophone with a properly setup viewing room, you should definitely be able to notice the resolution enhancement that 1080p brings. However, if you are an average consumer with a flat panel on the far wall of your family room, you are not likely to be close enough to notice any advantage. Check the chart above and use that to make your decision.

ISF states the most important aspects of picture quality are (in order): 1) contrast ratio, 2) colour saturation, 3) colour accuracy, 4) resolution. Resolution is 4th on the list and plasma is generally superior to LCD in all of the other areas (but much more prone to reflections/glare.) So pick your display size, then measure your seating distance, and then use the charts above to figure out if you would benefit from the larger screen size. So be sure to calibrate your screen! I recommend the following for calibration.

- Lee Yuan Ying

TV guidelines

The TV’s size refers to the display screen – measured diagonally. Naturally, the larger the screen, the greater the display area will be. Screen size is primarily a matter of personal preference, along with available space. However, the larger the display the more HDTV excels! This is quite different from the “Big Screen” Analog TV’s of several years ago. Analog TV’s lower picture quality and inherent artifacts are magnified as the screen size increases. But since Digital-HDTV has virtually a perfect picture, increasing the size of the screen enhances the picture quality. Compare different displays and select the size that best fits your situation.

Direct View or Projection

Direct View Sizes range from approximately 30" to 40."
Rear Projection TV (RPT): Sizes range from approximately 40" to 70".
Wide Screen (16:9 ratio): Consider a Wide Screen if most of your viewing will be High Definition Programming. Traditional Square Screen (4:3 ratio): Preferable if most viewing will be standard (NTSC) analog TV.

HDTV Resolutions

The ATSC Standard for High Definition Television requires a resolution of (either), 1080 interlaced lines, or 720 progressive scan lines; or higher. Lower (Digital TV) resolutions – 480i and 480p are both acceptable as SDTV Resolutions.

Although NTSC Analog TV also has 480i resolution, SDTV’s 480i improves the picture quality, since it’s Digital.

A Digital-HDTV Monitor is able to accept all ATSC TV Signals; the incoming DTV signals are converted to the TV’s "native" resolution. However, an External HDTV Receiver is required before an HDTV Resolution can be displayed. At present, Digital TV’s have both NTSC Analog TV and ATSC Digital TV Receivers built-in, allowing display of both Analog TV and Digital (SDTV) pictures.

I’ve read various articles debating the importance of the 1080p. I want to set the record straight once and for all: if you are serious about properly setting up your viewing room, you will definitely benefit from 1080p (and even 1440p.) Why? Because the 1080p resolution is the first to deliver enough detail to your eyeball when you are seated at the proper distance from the screen. But don’t just take my word for it: read on for the proof.

There are a few obvious factors to being able to detect resolution differences: the resolution of the screen, the size of the screen, and the viewing distance. To be able to detect differences between resolutions, the screen must be large enough and you must sit close enough. So the question becomes “How do I know if need a higher resolution or not?”. Here is your answer.

Based on the resolving ability of the human eye (with 20/20 vision it is possible to resolve 1/60th of a degree of an arc), it is possible to estimate when the differences between resolutions will become apparent.

- Geralyn Ong

Trigo Application

Sorry for the Delay, our group was facing a technical error

First method

We use the Pythagoras Theorem to derive a formula for finding the distance between two points in 2- and 3- dimensional space.

This allows for an accurate measure of the closest straight line to the screen

Let P = (x ₁, y ₁) and Q = (x ₂, y ₂) be two points on the Cartesian plane

Then from the Pythagoras Theorem we find that the distance between P and Q is

In a similar way, it can be proved that if P = (x ₁, y ₁, z₁) and Q = (x ₂, y ₂, z₂) are two points in the 3-dimensional space, the distance between P and Q is

2^nd method

Trigon is also a good way of measuring the distance and the angles involved in calculating whether or not someone is in the optimum viewing range. This is especially useful with 3d trigon, as we can arrive at a more conducive result with 2 planes instead of one

We have to calculate the following:

-Current viewing angle: Based on the inputs, this is the viewing angle or arc for your set up.

-Maximum recommended viewing distance: Based on data from Electro home, which suggests a viewing distance of three to six screen widths for video. This corresponds to the point at which most people will begin having trouble picking out details and reading the screen. Probably too far away to be effective for home theatre, OK for everyday TV viewing. Most people are comfortable watching TV between this distance and half this distance.

-Maximum SMPTE recommended viewing distance: SMPTE standard EG-18-1994 recommends a minimum viewing angle of 30 degrees for movie theatres. This seems to be becoming a de facto standard for front projection home theatres also. Viewing from this distance or closer will result in a more immersive experience, and also lessen eye strain caused by watching a smaller image in a dark room.

-Maximum and Recommended THX viewing distances: THX also publish standards for movie theatres to adhere to for THX certification. THX requires that the back row of seats in a theatre have at least a 26 degree viewing angle and recommends a 36 degree viewing angle.

-SMPTE and THX screen widths: Based on the viewing distance supplied to the calculator, these are the minimum screen widths required to meet the SMPTE and THX recommendations discussed above.

-Viewing Distances based on Visual Acuity: These distances are calculated based on the resolving power of the human eye (reference), or visual acuity. The human eye with 20/20 vision can detect or resolve details as small as 1/60th of a degree of arc. These distances represent the point beyond which some of the detail in the picture is no longer able to be resolved and "blends" with adjacent detail.

This guideline would be difficult to exceed in a home theatre, with most vertical viewing angles in the 15-20 degree range. See the diagram below for an example.

The THX cinema standards have no references to a "best" or "optimal" vertical viewing angle. However, normal human vision's optimal cone of vision has a radius of approximately 15 degrees. From this I'd suggest that anything in the range of 10-20 degrees would be good, with larger values causing increased eye and neck strain.

- Ho Zhen Hao