Play with the numerical camera values, because (if I remember correctly) you can get a greater view distance that way than with the visibility buttons. Give it a try.
Btw, I think calling it a "HUD" is not a great idea, since it'll lead to confusion. HUD stands for Heads Up Display, and refers to the data displays on a screen, not the actual view of whatever is being monitored or rendered. It was originally something created for military pilots so they wouldn't have to look down at their instruments to get the information they needed, allowing them to keep their head up, hence the name and subsequent acronym. Ok, enough unnecessary info out of me.
