There are a few reasons why this could be happening. The VGA connection is probably giving you a brighter or "more true" quality picture because VGA doesn't hold as much video content as a HDMI cables does.Every display device or interface has its own RGB color range that the device can manage or read. This is why there can be compatibility issues between different devices. HDMI cables are capable of streaming Full 1080p HD video, so the number range of colors are higher than standard streaming video. So if your projector's RGB color range is different and offset from its source, such as, a computer then it would read the incoming color different then the original images color. For example: A TV's RGB color code for Black may be RGB-16-16-16 and it's incoming signal is coming from a Computer that has a Black RGB color code of 0-0-0. This would account for the change in picture from one device to another.


To try to fix this problem, access your computer's display settings. This is most likely under your Control Panel/System Preferences. Then locate the Graphics card driver and if you are able change the cards range to the appropriate RGB color range.

Ben
Lead AV Tech, AA Rental