Thread: Project NiteVision - NiteMax + HUD + carputer

Originally Posted by jammy_basturd

I still don't think I quite understand what the problem is? Is it that your getting a double image?

How is your system currently set up? You have the CRT/LCD going through a lense being displayed on the collimnator?

Really wish I had some of the stuff readily available here in England so I could experiement around a bit!

I don't really have a setup per se. I've just been trying different things to find something workable.

A few setups I've experimented with...
LCD on dash reflecting onto collimnator
LCD projected through projected lens
Viewfinder CRT projected.

It's worse than a double image. The projection source is a lot brighter than the image. So you see an image and then a comparatively sun-like object (the lens) on the screen. Had the same problem when trying to project the lcd only worse as it was a much bigger lens.

I'm sure you've come across projectors in person (slide,film,etc). Picture looking into where the image comes out and how bright it is. That's what's showing up.

Throughout my experiments I found out that projecting was really hard exactly for the same reason. Plus it need space. I am very close in abandoning this project to be honest basically because I don't have the space in my dash to fit ANY type of system without truly gutting it. But I did find out some very interesting things by trial and error. By using two Fresnel lenses of different power on top of an LCD you can magnify the image AND focus it in the distance. This is something like the projectors do. Also this will diffuse the light of the LCD and will probably diminish the double image effect to minimum and you can also use a smaller LCD since you magnify it which means less space needed. I also tried a polarized film on the windshield which worked perfectly but then you have this dark piece of film on the windshield, not acceptable by me. The best colimnator i tried was the HUB glass from Electronic Goldmine, it has a pinkish hew and you can still see it in front of you but at least it is very transparent. If I was going forward with this I would use the Fresnel lenses and the windshield.

Originally Posted by spaceskater

Throughout my experiments I found out that projecting was really hard exactly for the same reason. Plus it need space. I am very close in abandoning this project to be honest basically because I don't have the space in my dash to fit ANY type of system without truly gutting it. But I did find out some very interesting things by trial and error. By using two Fresnel lenses of different power on top of an LCD you can magnify the image AND focus it in the distance. This is something like the projectors do. Also this will diffuse the light of the LCD and will probably diminish the double image effect to minimum and you can also use a smaller LCD since you magnify it which means less space needed. I also tried a polarized film on the windshield which worked perfectly but then you have this dark piece of film on the windshield, not acceptable by me. The best colimnator i tried was the HUB glass from Electronic Goldmine, it has a pinkish hew and you can still see it in front of you but at least it is very transparent. If I was going forward with this I would use the Fresnel lenses and the windshield.

Weird, my hud glass doesn't have any hue, but the side that aims away has a very light spotted look.

I agree it's a *****. I did some experiments with defocusing the image itself, looks like it might work.

I did some research on defocusing and consulted my trusty "Computer Graphics: Principles & Practice by Foley & Van damme", (I'd really like to get the second edition with the code in english, hmm looking it's only $62, I think I paid $100+ for the original).

Most of the stuff I came across was way over done. I mean, this is a special case of depth of field, projecting a plane perpendicular to the viewer at an abitrary focal length, so it's a lot simplier than projecting abitrary objects in an abitrary scene.

The biggest problem I have is that most programs I have access to only allow small filters (ie 5x5) which isn't really enough to creat a large enough "circle of confusion".

I need a bigger matrix, so one of these days, maybe this weekend, I'll write a program to do it. I wish the Imagemagick had a better example of plugin filters.

I tried doing some tests with a camera lens and some printed samples of the unfocused pictures which "kind of" worked. It got a little sharper but not enough, I think this is mainly because I'm using a printout instead of a transparency and hampered by the resolution of the printer.

As soon as I get around to writing the filter program, I'll do more tests. Maybe in the interim, create some hi-res images and get them printed to transparencies at kinkos or something.

On the plus side, if it does work, not a terriblly consuming operation, so realtime is probably well within reach.

If this doesn't pan out, I'm going to just say hell with the hud for now. The plan has always been to have a lcd gauge cluster replacement so I can live without it.

Originally Posted by jarofsonicmen

OK, another stupid interjection:
http://www.rickleephoto.com/rlcoll.htm

How about ditching the HUD part, and just projecting from the LCD onto a single fresnel lens? OK, it kills the overlay (which apparently we're not having much luck with) but as a benefit, it does away with the double-image problem (if you angle the lens at the right angle).

Something like this (pardon my ASCII art - ognore horizontal lines to preserve spacing)
__/ <- windshield
_/__\ <- fresnel lens
/____\
\ <-LCD

It doesn't give you the overlay, and poses some issues for protecting the LCD from sunlight, but it might give you part of what you're looking for. I would fear for the legality of raising the top of the screen above the line-of-sight to the front of the hood though.

It's a thought, but if I'm going to have an obstruction, I might as well just put the lcd there itself. (Well maybe not if I'm worried about theft)

Originally Posted by NiteMax Mark

I'm back from my trip.

Who do I owe what? I remember trying to get the VGA thing to work with the LCD and I also have a bunch of unclaimed lenses here.

Welcome back Mark.

A couple of quick questions when you get the chace. Can you run Svideo directly to the cameras?

And also, the little feature connectors, do you have any with all the wires in or do they all have the others cut?

Crap, i go anitsocial for a bit and i lose pace wiht the thread. Okay,

@shotgun, when did you switch over to the gauge cluster side? I'm not understanding the purpose of your project with the camcorder viewfinder, although

@Alti...where are you man?

More questoions to follow...