Lumagen VisionPro - Manual (Page 16)

Vision Pro
™ User Manual and Installer Guide
© 2003 Lumagen, Inc. 13 Rev 1.13
Hints For Optimal Picture Quality
•
Proper calibration, along with the use of high-quality cables, is as important for
attaining the best picture as are deinterlacing and scaling. If you don’t have one,
purchase a DVD setup disc, such as AVIA™, or Digital Video Essentials™ and watch
the training lessons provided.
•
If possible, use a power conditioner for the video source, video processor and the
display. Power line noise is at least as important an issue for video as it is for audio.
•
For fixed-pixel devices, use RGBHV from the Lumagen to drive BNC inputs, when
available, to minimize noise. For RGB, “Luma noise” is distributed across the red,
green and blue channels but for component, Luma noise is all on the Y (Luma) channel.
So, RGB sources can show lower noise levels since the weighting of the three channels
for “Luma” as perceived by the viewer tends to filter out some of the Luma noise.
•
Contrary to popular opinion, most fixed-pixel displays look best running their input at a
resolution higher than their native resolution, such as 1024p, and in some cases 1080i,
for a 720p or 768p display. This is because the process of “down-sampling” the higher
resolution to the display’s native resolution can filter out some of the noise and provide
more detail. Note: Rules for display of Video are completely different than for the
display of PC data. For display of PC generated data, such as spreadsheets, the PC
resolution should be set to match the native resolution of the display.
•
Avoid running video signals through the video switch inside receivers, as these tend to
degrade video quality. The rule of thumb for a video switch is to have 10 times the
bandwidth of the video being switched. This equates to 70 MHz for SDTV and 300
MHz for HDTV switching.
•
Component inputs on some RPTVs and projectors do not work with standard width
HSync pulses. When using component video to drive the display, if there is a “green
cast” the likely cause is a design problem in the circuitry inside the display. Changing
to bilevel sync, and/or making the HSync pulse narrower with the Lumagen HSync
Width command (
MENU 0 9 4 0
) can help eliminate this problem.
•
A system’s “ground loop noise” can cause problems. This shows as a screen-width
horizontal-band of intensity variation. Since the Lumagen case “floats” it may need to
be grounded to the video source and/or display.
•
Component DVD sources provide the best standard-definition picture quality, but
SVideo sources are often a bigger challenge and therefore can show more improvement
using Lumagen. Since many satellite receivers, and other video sources, only have
composite and SVideo outputs, this improved SVideo performance is important for
many installations.
•
Memory A (
MEMA
) and memory B (
MEMB
) can be used to have two independent
configurations, such as for day (bright room) and night (dark room). One difference for
this example is that the black level will be set higher for daylight viewing than for
viewing in a darkened room. To program MEMB to be different, first setup MEMA
normally, use the input copy command to copy to MEMB, than adjust MEMB as
desired. Remember to save changes.