User manual

Appendix - Still Images and Computer-
Harmony 2ES and 4ES 79
Progressive vs. Interlace (Field Rendering)
Computer monitors use progressive interlace, which means
that each scan line is done in order from the top of the
screen to the bottom.
Video monitors use interlacing, which means that the even
lines are followed by the odd lines.
• It is important to avoid single horizontal lines, as they
will flicker. This flicker comes from the fact that the line
is off on one field and on in the other. Use anti-aliasing
on all lines and/or use thicker lines to avoid this flicker
problem.
• Most computer graphics programs have an option for
“field rendering”. This should be selected if the
animation will be displayed on a video monitor or
television.
Color Issues
The range of color that NTSC can produce is different from the
range of RGB values that a computer monitor can display.
Color produced outside the range of acceptable NTSC values
are called “illegal values” because they have the potential to
interfere with broadcasting parameters and can cause
problems like interference with adjacent channels.
This can also happen in cable channels where the text from
“bulletin board” type displays can bleed into another channel.
In particular, excessive red can cause severe problems on a
television screen or video monitor.
• It is best to keep any value for red, green, or blue under
a value of 234. For example, pure red for video
purposes should be 234,0,0 (hex EA0000), and it is
preferable to make it more of an orange color.
• Pure white should not exceed 234,234,234, but it is
better to avoid pure white because it can cause text on
top of it to flicker excessively.
• Pure black works well as a background for most colors,
but pure black (0,0,0) should not be used. Television
black should be 18,18,18 to stay within the legal range
of colors.