2 Place Collimated Display

[wledzian]

Sounds like what I'd expect a rear-projection screen to look like. You're correct; the projectors beam through the shiny inside surface and diffuse on the exterior surface. The reflections on the inside are just the reflections of other parts of the screen - the bane of highly curved rear projection screens. Basically, contrast is reduced because in addition to the direct light from the projector, you're getting lots of scattered light from the rest of the screen. If you can make the inside surface highly reflective to off-axis light, you increase the contrast, since less of the scattered light gets through to the viewing surface.

Some quick work with my calculator comes up with a mirror radius of 9.5 feet, which just happens to be a radius that Barco offers.

I'm not entirely surprised that the screen is not perfectly round; I'm sure the pros have some more advanced tools to calculate an acceptable screen shape that produces a better image for both pilots.

[xplanematt]

The more I learn about this screen, the more I like it.

When you say 9.5ft, are you talking about the mirror at its deepest point, or do you mean one of the bows? If the latter, that is almost perfect.....my Sabreliner is 12ft long (including radome), the pilot's head is going to be about 1 to 2 feet from the back of the cockpit (depending on where the seat is positioned), and I can get at least another foot of clearance by pulling the radome. And I was planning for a 20ft wide building, but I may be able to squeeze in 24ft or so to allow for the mirror support structure. I assume the shape of the mirror should match the projection screen's profile exactly?

Alright, I'm off to the backyard to get new measurements for the shop!

[wledzian]

9.5 feet is the radius of the sphere that defines the mirror. The lower bow will be closer in, at about 84 inches radius.

[xplanematt]

Awesome, I think I can work that. I'm guessing the Sabreliner 60 nose is close to the same size as the Lear 60 nose, hence the choice of a 9.5ft screen (just the right size to go in front of the cockpit).

This changes my shop layout a bit. I will be doing a 24x25ft floorplan (my city allows a max of 600sqft for outbuildings...), that should provide enough space for the mirror structure, plus the trailer/sim setup.

Wayne, thank you again for all the info, it is invaluable! I am sure I will be back with more questions once the shop is built and I begin the mirror build.

Matt

[geneb]

If they have a max for outbuildings, just make it an addition to the house and make it bigger. g.

[xplanematt]

That is exactly what my wife suggested! Unfortunately the only side of the house that has room for expansion is also where all the utilities come in....gas, electric, cable, even the AC unit is situated next to that wall, AND the sewage line goes right next to it! I don't really see a way to make it work.

Matt

[geneb]

That sucks. Can you make the outbuilding 2 stories? That way you could have a workshop above... Better yet, you could move. g.

[xplanematt]

The poopie-heads thought of that too...10ft walls max, 15ft max roof peak! I tell ya, having been raised in the country, this city living is a rude awakening. And this city is actually pretty loose and non-restrictive compared to many other places, and there is no HOA (I would *never* live under an HOA). Where I come from, if you wanted to build something, you go to the lumberyard, pick up what you need, bring it home and start building the same day.

Moving? Now THAT is taking the hobby to an even further extreme! :P Naww seriously, I like my house too much, and the fact that it's safely below my means...yes I want a quick mortgage payoff. Though I do have an idea in the back of my mind to eventually buy some property in the country and build a bigger shop for more sim projects...........

Matt

[geneb]

Can you have two pole-barn style buildings made and use one for a shop and one for a sim room? g.

[xplanematt]

Yes, two 300sqft buildings.... :/

I applied for my building permit last week, and discovered that even though I generally only have to be 10ft from the back of the property and 5ft from the side, my property has a "utility easement" that requires 10ft from the side! I am now down to a 21x26ft building and sacrificing a fair portion of my second, full-length driveway (where the Sabreliner currently resides). HOPEFULLY they will at least approve THAT.

To keep this somewhat O/T....this weekend at CockpitFest I discovered the importance of isolating my visual system from stray light. My old sim has, until now, only been used indoors. We had everything in a hangar at the Cold War Air Muesum in Lancaster, with the doors partially open. The daylight mostly washed out my projection screen. My enterprising wife helped me come up with a temporary cover for the sim and screen, which made it usable. I think I will either not put windows in the shop, or use some sort of window-blind assembly that provides a complete light seal. Any ideas?

Matt