Choosing the right video cable – not always the easiest
VGA, SDI, DVI, HDMI…the list goes on and on. So how do you choose the right cable for your application? Is there a set of rules for what makes the most sense for different applications? At the end of the day, what are the cables you should have in your workbox to ensure your event goes off without a hitch.
Today we are launching a 4 part series based on our thoughts on video cables from years of experience. First up, VGA.
VGA – Video Graphics Array
VGA is an analog video standard using the 15 pin D-sub connector. Originally 640×480, but it now can support resolutions over 1920x1080p. Although VGA is one of the older standards, it is still very commonly found on PCs, TVs, and projectors. Due to being an analog cable, the signal quality is highly dependent on cable length and quality, particularly at higher resolutions.
Generally speaking with a high quality VGA cable you can run about 100’ at 1920×1080. For longer runs plan on using a distribution amplifier to boost the signal, or use shielded RGBHV cable. VGA has a number of advantages. Due to its popularity it is a safe bet that most equipment you encounter will support it. Also, because VGA is analog it does not carry EDID. Disadvantages of VGA mostly stem from the analog nature of the standard. In addition to cable length and quality concerns, analog color is slightly different than digital, something to keep in mind especially when using analog and digital systems side by side.
An item to be mindful of with VGA is that it does not support HDCP, so protected content such as Blu-Ray discs and purchased HD movies often will not play on a display connected via VGA.
Lastly, VGA has a big pitfall and that is the diversity of the standard. Over time over many VGA display resolution standards have been developed. The most popular standards are VGA (604×480) XGA (1024×768) and WUXGA (1920×1080). It is extremely important when implementing VGA based signal paths that all the equipment in use support the proper standards. For example, if you are planning to run 1080p signal to 2 projectors, you need a WUXGA DA, an XGA DA won’t support the proper resolution.