HUD...how far out is the focal distance?

[Brad W]

So I'm in a loaner car while my car is in the shop, it has a HUD. It's more of a gee-whiz thing that I don't really see as any sort of safety improvement, almost more of a distraction. It only shows the speed and a few indicators for the adaptive cruise control status
Anyway

It has me wondering something about military HUDs. I know there are lots of military pilots here that will know!

This HUD in the car seems to be focused for a distance somewhere just outside the windshield as best as I can tell. It's hard to tell for sure. I think closer to the windshield than the bumper. Maybe it's double the distance from the projector to the glass. Regardless, I suppose in a way it's better switching my eye's focus from infinity to this point as opposed to changing from infinity all the way to the instrument cluster inside...but it's still noticeable changing my focus back and forth.

It seems to me that this thing would be better if it was focused for something closer to the car that I'm following (or to infinity) so that I can see the display while also seeing everything outside.

So, how are military HUDS set up? Are you focusing on the glass inside the cockpit, or is it adjusted for something else?

 

[AV8R_87]

In the ones I dealt with, it was definitely infinity, or not that far off from it.

In cars, I've noticed the same thing - they seem to be focused ar most a couple car lengths in front, at most. Definitely not infinity. It doesn't make sense to have them focused that far, though. Your eyes are looking at relatively close stuff when driving.

 

[35 AoA]

I honestly don't really understand the question. Mil aircraft HUDs I've flown have been very easy to bring into the visual scan/focus. It is projected onto the vertical HUD glass portion, which sits a couple feet out in front of your face. Yes, like was said above, there is probably some difference in the distance of things and objects you are normally looking at. But on short final, or close-ish to another airplane like a gun attack, I haven't noticed a problem. I've driven a couple cars with HUDs and they seem very different and not at all as easy to scan. For whatever that's worth. I don't know if that means one is focused at infinity or not.

 

[Noah Lorang]

True HUDs are infinity focused, which takes a fair amount of bulky and expensive optics to achieve, or not-bulky-but-even-more-expensive optics. The size & cost is why car HUDs don't infinity focus, and also why you haven't seen HUDs become a thing in smaller general aviation aircraft (yet) -- even if you could swallow the cost, the form factor is tough to make worth.

The Epic Optix Epic Eagle 2 is a true infinity focus HUD targeting light GA, and the cost isn't even bad ($1500), but the form factor is still tough in a normal cockpit.

 

[Brad W]

I did a little more playing with the loaner car this AM. I found that i fI use the car's onboard navigation instead of android auto, the HUD projected quite a bit of actually useful info. Most of it was still focused much too close, but some of the turn ahead arrows and animation seemed to be focused at maybe 2-3 seconds ahead
I take back what I implied about it being a total gimmick.

I figured the real ones would be something like infinity...thanks!

 

[TCABM]

… I found that i fI use the car's onboard navigation instead of android auto, the HUD projected quite a bit of actually useful info. …!

Wife’s car has the HUD. Turn by turn nav, speed (and speed limit signs) and a lot of usefule info can go up there, but I use the declutterred setting.

I’ve found CarPlay lets thru a lot more info and guidance from Apple Maps than any other nav app.

 

[Pinecone]

In the ones I dealt with, it was definitely infinity, or not that far off from it.

In cars, I've noticed the same thing - they seem to be focused ar most a couple car lengths in front, at most. Definitely not infinity. It doesn't make sense to have them focused that far, though. Your eyes are looking at relatively close stuff when driving.

Yes, military HUD is focused at infinity.

BTW, you SHOULD be looking further down the road. Safe driving course teach somewhere around 15 second ahead or more. At 60 MPH, that is about 1/4 mile.

 

[Mikey52]

You really only glance at the HUD in an automobile. Just as if you were checking your speed in the dash or the turn coming up on your center console display. After a little while you learn to see the HUD without concentrating on it.

 

[Brad W]

BTW, you SHOULD be looking further down the road. Safe driving course teach somewhere around 15 second ahead or more. At 60 MPH, that is about 1/4 mile.

I learned the same thing. Most folks focus far to close in they say (and I believe). I try to look much further out. However, since most folks follow too close it's not realistic to really focus out 15 seconds or thereabouts unless the road is empty.

So I rekon the reality is something more like looking ahead of the car you're following...roughly to the car that your leader is following....so real world I find that when I follow 4-seconds behind that is significantly further back tahn most folks so two cars ahead is more like 8-seconds max

But for me anyway, I find that I tend to look ahead of the car at key times but ordinarily my focus is flip-flopping between something out in front of the car that I'm following to the back of the car that I'm following. It's basically keeping that longer but partially obstructed distance in awareness but not usually in focus

You really only glance at the HUD in an automobile. Just as if you were checking your speed in the dash or the turn coming up on your center console display. After a little while you learn to see the HUD without concentrating on it.

I think since it was a new experience for me, it was a distraction and I was looking at it far more often than I really needed to. More often than I would ordinarily be looking at the instruments. That's why I became conscience of refocusing my eyes from near to far to near.... and because of that, it dawned on me that the utility might be better if it was in focus while I was looking 8 seconds or more ahead...or maybe at least 4 or 5 seconds...

 

[Pinecone]

I learned the same thing. Most folks focus far to close in they say (and I believe). I try to look much further out. However, since most folks follow too close it's not realistic to really focus out 15 seconds or thereabouts unless the road is empty.

So I rekon the reality is something more like looking ahead of the car you're following...roughly to the car that your leader is following....so real world I find that when I follow 4-seconds behind that is significantly further back tahn most folks so two cars ahead is more like 8-seconds max

But for me anyway, I find that I tend to look ahead of the car at key times but ordinarily my focus is flip-flopping between something out in front of the car that I'm following to the back of the car that I'm following. It's basically keeping that longer but partially obstructed distance in awareness but not usually in focus

Hmm, sound like you have taken the Smith System Training.

I look as far ahead as possible, sometimes 20 - 30 seconds depending on the road and conditions.

Looking to the car ahead of the car you are following is a good start, but due to people tailgating, may still not give you a safe stop without being hit.