Direct TV and Your TV's Resolution Quality

To understand the significance of resolution in Direct TV, let's begin with the television we know - the traditional, NTSC-analog TV. It will help to take a closer look at how the images we see on the TV screen are formed.

In pictures made on film - 'movie-pictures' - images are projected on to the screen as a complete picture, in a single action. Creating video or television pictures is quite different.

The pictures and completed images we see on a traditional CRT (Cathode Ray Tube) TV screen, are really a series of horizontal and vertical lines; (visualize Horizontal Rows and Vertical Columns) with these 'rows' and 'columns' consisting of "tiny" dots or dashes.

The 'rows' are commonly called "Scan Lines" since they are applied to the screen as the 'electron gun' scans from left to right, and top to bottom. (This application of scan lines is sometimes described as 'painting' or 'drawing' the scan lines)

The 'electron gun,' located at the rear of the picture tube, is basically a wire filament that becomes heated due to resistance as electric current is applied. The heating action causes electrons to collect around the filament. By applying a high, positive voltage, the negatively charged electrons are accelerated away from the filament, and towards the phosphor-coated, interior surface of the picture tube. The accelerating electrons are concentrated in a narrow beam which strikes the coated surface of the picture tube, causing the phosphor to glow in that focused area..

Where a picture's scene is darker, the electron beam is 'weaker' - or less intense - and the phosphor 'glow' is less. Where a scene in the picture is brighter, the electron beam is more intense, and the phosphor 'glow' is brighter. The electron beam scans across the surface of the picture tube, in direct coordination with how the original scene was scanned by the sensor in the television camera. As the scan lines vary - changing from bright, to dark, with many intensities in between - images are formed on the TV screen.

As stated above, the "resolution" of a TV is how well it is able to distinguish between the alternating light and dark lines, when these are spaced close together. If the lines are too close together (exceeding the resolution limits) they will appear merged - being neither dark, nor light, but blurred into 'muddy' shades of gray.

A Direct TV that is able to "DISPLAY" TV signals in HDTV-Resolution - 720p - 1080i or 1080p - is "HDTV-Capable." A Digital TV that is HDTV-Capable - AND - has an 'Internal' HDTV Receiver is called an "Integrated" HDTV. A Digital TV that can display HDTV-Resolution Pictures, but requires an 'External' HDTV Receiver is commonly referred to as an HDTV-Capable 'Monitor'.

480i - The picture is 704x480 - (60/2 interlaced frames per second) = 30 complete frames per second.

480p - The picture is 704x480 - 60 complete frames per second.

720p - The picture is 1280x720 - 60 complete frames per second.

1080i - The picture is 1920x1080 - (60/2 interlaced frames per second) = 30 complete frames per second.

1080p - The picture is 1920x1080 - 60 complete frames per second.