Hacker News Reader

There is a reflective tape you buy specifically for cars that came with HUD from the factory. You could also measure the tach signal for a tachometer too.

(http://www.ebay.com/itm/Head-up-display-OBD-II-HUD-S-200-Typ...)

View on HN

From the pictures it looks like the projection is focused on the film (also true for OP's link), where as in newer HUDs (such as my 2013 BMW) it looks like the projection has infinity set as the focus thus achieving the result of it looking like it's floating in a distance, and I don't need to adjust the focus of my eyes to look at the contents of the HUD. But I have not reviewed the tech spec, it just seems this way and the videos/pictures in OP's link and your link look way too jarring.

OP uses a fresnel lens and gives instructions on how to focus the HUD at infinity to avoid this problem.

Reply on news.ycombinator.com