Epiphan VGA2USB Pro - Manual (Page 146)

18. Advanced topics Configuring VGA modes
Page 146 Epiphan Frame Grabber
However, configuring VGA modes can be useful if you have
special requirements or if the VGA source and Frame Grabber do
not automatically select the VGA mode that you want. To resolve
problems like this you can configure VGA modes to either limit
the standard VGA modes that the Frame Grabber can operate in
or you can add one or more custom VGA modes and configure
the Frame Grabber to operate in a custom VGA mode.
Figure 43:Configuring VGA Modes
The Frame Grabber acts like a display device. Many VGA sources
set the VGA mode that they use by checking the VGA modes the
display device can use and then setting their VGA output mode
to match. So if you can control the VGA mode that the Frame
Grabber uses you may be able to control the VGA mode that the
VGA source uses.
If the Frame Grabber and the VGA source cannot automatically
select the VGA mode that you want them to use, you may be able
to resolve this by only allowing the Frame Grabber to operate in
one or some standard VGA modes.