Many consumers get so snowed by the terms being thrown around they forget to grasp the basics of video technology and home theater. But we all started out with the same dual speakers and long playing records. Here are some old-school video and audio rudimentary concepts explained to help make the connection between the tape-playing Sony Walkman generation and the many-texting Sony Bravia ‘tweens.
A video display is made up of pixels. Video displays can be screens, monitors, and were formerly called CRT’s. Television tubes were much different than original computer monitor technology, but today a technological convergence has taken place.The methods for picture tube delivery to a visual effect now involve static and dynamic convergence, grayscale and inline adjustments.
Plasma TV and 3DTV are the highest level performance video television devices available for home theater use. Some have enhanced audio capabilities, and come are merely devised with output and inputs for specialized sound equipment. Light and color are discussed in circuitry as luminance and chrominance. Distance of the viewer to the screen becomes important when assessing these technologies for home theater use.
Separation of video and audio signal and voltage elements has given rise to a specialized technology originally necessary to bring both product from the sound and screen together with the highest quality result. Yet RF-amplifliers (radio frequency) selects and amplifies signal and current to deliver a unified frequency output per bandpass. Audio sound wave degeneration (dull sound) and oscillation (that feedback whine) can occur.
The computer monitor of today inside a modest desktop computer package might be a high definition unit resolutional dimensions above what sits on the kitchen counter. A pixel has three dots, red blue and green. Merging these three colors produces white. Gray scale adjustments to produce a neutral white screen effect work to optimum picture result. The front projection or rear projection unit has differing setups for the source and amplitude of signal.
Video resolution is termed in quality as dpi, dot per inch. Dot pitch is the distance between center points of a video module or CRT’s adjacent horizontal pixels and is usually rendered for TV screen specifications in millimeters. The smaller the distance between these centers, the higher the screen resolution is. Thus a 54 inch color TV with .48 dpi does not have as good a picture quality as a 28 inch TV with 1080p.
Amplifiers are required for high performance audio sound quality because the channeling of circuit signal can introduce internal noise from within and external noise from without. Noise gets canceled by the amplifier and the quality sounds get enhanced. Depending on the environment, even cellphones, electric appliances, and power lines can create noise inside the channeled sound circuits from their EMF fields.
Projection televisions work with projections of light to specialized receptors. Luminescense over signal takes priority in projection video products. Distortion and focus of the light beam emerge as controlling factors in picture quality. Visual impedance can occur when distance distorts the projection array, and a “blur” forms. Calibration of the TV device controls maybe necessary to adjust these results.
Discussion of interlaced scanning involves the rasterized result of vertical and horizontal lines of TV signal. The bandwidth or channel frequency of signal that conveys video information informs this interlaced combination of vertical and horizontal e as a picture. The continuous re-informing of the picture via signal per vertical and horizontally scanned location, and the refresh rate of the screen image renders the picture continuously as video.
Non interlaced scanning causes all the raster locations, vertical and horizontal, to change (per refresh). Since interlaced scanning only refreshes half the lines at a time, the result is faster but not as accurate. These changes of information visible on-screen render a smoother effect with less flicker. Progressive scanning is another name for non-interlaced scanning.
HDTV is a different technical standard of television video than most of us grew up with. High definition video captures the whole breadth of change per video frame, and the enhanced ability to convey signal allows for the entire change per frame to be transmitted. Previous TV and video technologies were limited by what signal could be conveyed to reasonably constitute picture capture limits. HDTV allows for ultimate transmission of visual frame data.
