HP LP2480zx Using the HP DreamColor LP2480zx Monitor for Professional Video Ap - Page 3

Video Black Level - dreamcolor professional display

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 The monitor is fed an analog signal via the composite, component or S-Video inputs. These signals must be converted to an RGB progressive signal and input via one of the digital inputs, such as HDMI. When a video source that meets one or more of the above criteria is sent directly to the LP2480zx, a warning will be displayed onscreen and the color space presets will be disabled in the On Screen Display (OSD) menu indicating that they cannot be selected. In this mode, the monitor is operating in its "native" mode, at the full panel gamut and with no tone response, gamma, or other corrections applied. The resulting image will typically be highly saturated and will not match the expected levels. Fortunately, Gefen converter interface mentioned above can compensate for all of the above conditions. Usage and Application Applying proper color gamut remapping allows the HP DreamColor LP2480zx to accurately emulate the display characteristics of a broadcast video monitor. Color space emulations are provided for both high definition (ITU-R BT.709) and standard definition (ITU-R BT.601) formats. These color spaces can be easily selected via the OSD's "Color Space" menu.  If you are working with high definition sources (either 1080-line or 720-line), you should choose the Rec.709 color space and the monitor will be configured to match the characteristics of a high definition broadcast monitor. Remember that any interlaced or PsF sources must be converted to true progressive source or color gamut mapping will be disabled.  If you are working with standard definition sources (typically either NTSC or PAL), the color space you choose depends on how you convert the signal prior to feeding it to the monitor. The Gefen converter allows for three different methods of conversion for these signals. (We will discuss these options in greater detail at the end of this white paper.) - Choose the Rec.601 color space if you output the signal from the Gefen converter as either a 486/59.94 or 576/50 signal. - Choose the Rec.709 color space if you output the signal from the Gefen converter as any of the "Graphics" formats (ex. 640 x 480, 1024x768, and so on). - Choose the Rec.709 color space if you output the signal from the Gefen converter as any of the High Definition formats (ex. 1080p/59.94, 1080/50, 720p/59.94, 720p/50, and so on.) Video Black Level Depending on your video source, some additional adjustment of the HP DreamColor LP2480zx may be required. In the computer and print worlds, black and white are considered absolutes. "Black" is assigned a value of 0 (zero) for each channel and it is not possible for anything to be blacker than black. Likewise, "white" (assuming 8 bits per color) is assigned a value of 255 for each channel and it is not possible for anything to be whiter than white. (This corresponds to the print world where white typically means no ink has been applied to the page and black means that all of the ink has been applied.) Similarly, LCD monitors are designed to treat black and white as absolutes in order to attain the widest displayed contrast ratio possible. (CRTs do not treat black and white as absolutes as they are analog devices that can be calibrated to display a wide range of voltages and display those voltages at various levels of light output.) In the professional digital video world, however, black and white are not treated as absolutes. Instead, it is possible for a video signal to contain portions that are "blacker than black" and even that are "whiter than white." The existence of these is due primarily to the desire to preserve aspects of the analog signal. "Blacker than black" voltages are used in analog signals for synchronization Using the HP DreamColor LP2480zx for professional video applications 3

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Using the HP DreamColor LP2480zx for professional video applications
3
The monitor is fed an analog signal via the composite, component or S-Video inputs. These signals
must be converted to an RGB progressive signal and input via one of the digital inputs, such as
HDMI.
When a video source that meets one or more of the above criteria is sent directly to the LP2480zx, a
warning will be displayed onscreen and the color space presets will be disabled in the On Screen
Display (OSD) menu indicating that they cannot be selected. In this mode, the monitor is operating in
its “native” mode, at the full panel gamut and with no tone response, gamma, or other corrections
applied. The resulting image will typically be highly saturated and will not match the expected levels.
Fortunately, Gefen converter interface mentioned above can compensate for all of the above
conditions.
Usage and Application
Applying proper color gamut remapping allows the HP DreamColor LP2480zx to accurately emulate
the display characteristics of a broadcast video monitor. Color space emulations are provided for
both high definition (ITU-R BT.709) and standard definition (ITU-R BT.601) formats. These color spaces
can be easily selected via the OSD’s “Color Space” menu.
If you are working with high definition sources (either 1080-line or 720-line), you should choose the
Rec.709
color space and the monitor will be configured to match the characteristics of a high
definition broadcast monitor.
Remember that any interlaced or PsF sources must be converted to true progressive source or color
gamut mapping will be disabled.
If you are working with standard definition sources (typically either NTSC or PAL), the color space
you choose depends on how you convert the signal prior to feeding it to the monitor. The Gefen
converter allows for three different methods of conversion for these signals. (We will discuss these
options in greater detail at the end of this white paper.)
Choose the
Rec.601
color space if you output the signal from the Gefen converter as either a
486/59.94 or 576/50 signal.
Choose the
Rec.709
color space if you output the signal from the Gefen converter as any of the
“Graphics” formats (ex. 640 x 480, 1024x768, and so on).
Choose the
Rec.709
color space if you output the signal from the Gefen converter as any of the
High Definition formats (ex. 1080p/59.94, 1080/50, 720p/59.94, 720p/50, and so on.)
Video Black Level
Depending on your video source, some additional adjustment of the HP DreamColor LP2480zx may
be required. In the computer and print worlds, black and white are considered absolutes. “Black” is
assigned a value of 0 (zero) for each channel and it is not possible for anything to be blacker than
black. Likewise, “white” (assuming 8 bits per color) is assigned a value of 255 for each channel and
it is not possible for anything to be whiter than white. (This corresponds to the print world where white
typically means no ink has been applied to the page and black means that all of the ink has been
applied.) Similarly, LCD monitors are designed to treat black and white as absolutes in order to attain
the widest displayed contrast ratio possible. (CRTs do not treat black and white as absolutes as they
are analog devices that can be calibrated to display a wide range of voltages and display those
voltages at various levels of light output.)
In the professional digital video world, however, black and white are not treated as absolutes.
Instead, it is possible for a video signal to contain portions that are “blacker than black” and even
that are “whiter than white.” The existence of these is due primarily to the desire to preserve aspects
of the analog signal. “Blacker than black” voltages are used in analog signals for synchronization