If you need to use a video extender with a video adapter or converter, you should position the adapter or converter as close to the video source as possible. For example, if you need to take a VGA signal from a computer and send it 200 feet to an HDMI projector, you should convert the signal from VGA to HDMI and use an HDMI extender.
Note: For more information on when to use cables or extenders, see the following FAQ: http://www.startech.com/faq/video_signal_converters_when_to_convert.