top of page
Digital Cinema Concepts
Digital Cinema Concepts HD979: 1080i - CRT HDTV
1080i is directly compatible with some CRT HDTVs on which it can be displayed natively in interlaced form, but for display on progressive-scan—e.g., most new LCD and plasma TVs, it must be deinterlaced. Depending on the television's video processing capabilities, the resulting video quality may vary, but may not necessarily suffer. For example, film material at 25fps may be deinterlaced from 1080i50 to restore a full 1080p resolution at the original frame rate without any loss. Preferably video material with 50 or 60 motion phases/second is to be converted to 50p or 60p before display.
Broadcasting standards - broadcast applications
For live broadcast applications, a high-definition progressive scan format operating at 1080p at 50 or 60 frames per second is currently being evaluated as a future standard for moving picture acquisition. EBU has been endorsing 1080p50 as a future-proof production format because it improves resolution and requires no deinterlacing, allows broadcasting of standard 1080i25 and 720p50 signal alongside 1080p50 even in the current infrastructure and is compatible with DCI distribution formats.Digital Cinema Concepts sell
Digital Cinema Concepts: Full horizontal detail
Interlacing provides full horizontal detail with the same bandwidth that would be required for a full progressive scan of twice the perceived frame rate and refresh rate. To prevent flicker, all analog broadcast television systems used interlacing.
Format identifiers like 576i50 and 720p50 specify the frame rate for progressive scan formats—but for interlaced formats, they typically specify the field rate (which is twice the frame rate). This can lead to confusion, because industry-standard SMPTE timecode formats always deal with frame rate, not field rate. To avoid confusion, SMPTE and EBU always use frame rate to specify interlaced formats, e.g., 480i60 is 480i/30, 576i50 is 576i/25, and 1080i50 is 1080i/25. This convention assumes that each frame in an interlaced signal contains two sub-fields in sequence.
Dynamic contrast - Brightness
The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions.
Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen. Digital Cinema Concepts HD979 for sale
Digital Cinema Concepts HD979 for sale:Methods of measurement for contrast ratio
Many display devices favor the use of the full on/full off method of measurement, as it cancels out the effect of the room and results in an ideal ratio. Equal proportions of light reflect from the display to the room and back in both "black" and "white" measurements, as long as the room stays the same. This will inflate the light levels of both measurements proportionally, leaving the black to white luminance ratio unaffected.
Some manufacturers have gone as far as using different device parameters for the three tests, even further inflating the calculated contrast ratio. With DLP projectors, one method to do this is to enable the clear sector of the color filter wheel for the "on" part and disable it for the "off" part This practice is rather dubious, as it will be impossible to reproduce such contrast ratios with any useful image content.
1080i is directly compatible with some CRT HDTVs on which it can be displayed natively in interlaced form, but for display on progressive-scan—e.g., most new LCD and plasma TVs, it must be deinterlaced. Depending on the television's video processing capabilities, the resulting video quality may vary, but may not necessarily suffer. For example, film material at 25fps may be deinterlaced from 1080i50 to restore a full 1080p resolution at the original frame rate without any loss. Preferably video material with 50 or 60 motion phases/second is to be converted to 50p or 60p before display.
Broadcasting standards - broadcast applications
For live broadcast applications, a high-definition progressive scan format operating at 1080p at 50 or 60 frames per second is currently being evaluated as a future standard for moving picture acquisition. EBU has been endorsing 1080p50 as a future-proof production format because it improves resolution and requires no deinterlacing, allows broadcasting of standard 1080i25 and 720p50 signal alongside 1080p50 even in the current infrastructure and is compatible with DCI distribution formats.Digital Cinema Concepts sell
Digital Cinema Concepts: Full horizontal detail
Interlacing provides full horizontal detail with the same bandwidth that would be required for a full progressive scan of twice the perceived frame rate and refresh rate. To prevent flicker, all analog broadcast television systems used interlacing.
Format identifiers like 576i50 and 720p50 specify the frame rate for progressive scan formats—but for interlaced formats, they typically specify the field rate (which is twice the frame rate). This can lead to confusion, because industry-standard SMPTE timecode formats always deal with frame rate, not field rate. To avoid confusion, SMPTE and EBU always use frame rate to specify interlaced formats, e.g., 480i60 is 480i/30, 576i50 is 576i/25, and 1080i50 is 1080i/25. This convention assumes that each frame in an interlaced signal contains two sub-fields in sequence.
Digital Cinema Concepts review
Dynamic contrast - Brightness
The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions.
Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen. Digital Cinema Concepts HD979 for sale
Digital Cinema Concepts HD979 for sale:Methods of measurement for contrast ratio
Many display devices favor the use of the full on/full off method of measurement, as it cancels out the effect of the room and results in an ideal ratio. Equal proportions of light reflect from the display to the room and back in both "black" and "white" measurements, as long as the room stays the same. This will inflate the light levels of both measurements proportionally, leaving the black to white luminance ratio unaffected.
Some manufacturers have gone as far as using different device parameters for the three tests, even further inflating the calculated contrast ratio. With DLP projectors, one method to do this is to enable the clear sector of the color filter wheel for the "on" part and disable it for the "off" part This practice is rather dubious, as it will be impossible to reproduce such contrast ratios with any useful image content.
bottom of page