# Thread: My Collimated Screen Concept

1. ## Re: My Collimated Screen Concept

Alrighty, so it's been a while since I last posted. In that time I've finally put together my own ray tracing worksheet. Right now it's not very user friendly, and it doesn't quite jive with what I've seen of wledzians work. I'm going to continue plugging away. Unfortunately all the free time I've enjoyed is about to evaporate as I'll be comin' off of leave and headed back to work. Hooray for Army Professional Development COurses! (not at all...). But, as I get more work done I'll post when I can.

P.s.

I'll work on getting the equations all put together so other folks can at least use them to work on their own stuff in a few days as well.

2. ## Re: My Collimated Screen Concept

This may be a silly question but why are you not reflecting your rays off of the spherical surface representing the mirror? I'm pretty sure that is the only way to size and place the screen i.e take 2 or more parallel rays (like you have) and reflect them off of the spherical surface and where they intersect defines a point on the screen. I may be totally misreading your diagram so forgive me if I am. I am definitely not totally up on the optics but followed Mike Powell and wledzian's examples. BTW, where in Alabama are you?

Best Regards,
Tim

3. ## Re: My Collimated Screen Concept

After talking to wledzian, I think that I was working under a completely different set of equations and assumptions. For what I was doing, it's correct. You'll see the reflection the way you're supposed to for the purposes of drawing a mirror...but...it won't give you points of intersection other than passing through somewhere around the focus of the mirror. I'm not super well versed in optics either, so I'm learning this as I go.

In so far as where in Alabama, I'm livin' it up in beautiful and balmy Fort Rucker.

4. ## Re: My Collimated Screen Concept

I see, the lines intersect around the (non perfect) focus of the sphere. Your design looks really cool and I hope you finish it. There doesn't seem to be any one thing that is too difficult about building these types of displays but it all adds up to a pretty good project. Of course, that is only the case after Gene and WLedzian actually figured out how to do it.

I used to fly a Saab SF340 into Dothan back in the 80's when I flew for NorthWest Airlink and passed by Fort Rucker many thousand times. Balmy is definitely understating it.