Display Screen: Overkill.

[geneb]

After getting my three projectors built, I needed to build a screen, right?

Guess what happens when you screw up your calculations?

You get this:



There are six segments to that screen which is 22.5 degrees short of 180. I didn't assemble the last two segments. The diameter of the screen is right around 24 feet.

Canvas makes a great screen material.



It turns out that the actual diameter for the screen should have been between 15 and 17 feet. Nothing like being off by nearly 9 feet, eh? *laughs* Fortunately, OSB is still pretty cheap and it makes a great building material as long as you understand its limitations.

The above picture also shows the three projectors I built. Each one will get its own tower to hold it in place. With any luck I'll get both the new screen parts and the towers done this coming weekend.

g.

[ANDYSMITH]

"projectors you built"?? please elaborate.

Andy Smith

[Sean Nixon]

"projectors you built"?? please elaborate.

Andy Smith

You read that correctly, projectors he built. I've seen the video!

[geneb]

Andy: I built three 1024x768 short throw projectors for a bit less than the cost of buying one.

I got the optics & light parts from http://www.diyprojectorkits.com.

Each projector is 30" long by 17" wide. They use 400W Metal-Halide bulbs with a color temp of 6500K. The bulbs are good for about 10k hours each and if memory serves, are less than $50 to replace.

If you head over to http://www.youtube.com/f15sim, you can watch a kind of walk-thru video I did on the projectors.

Sean: \o/

g.

[Sean Nixon]

So how come your calcs were so far adrift?

[geneb]

Pick any two:

1) I suck at math

2) I _really_ suck at Geometry

3) I have no idea



g.

[Sean Nixon]

LOL! I suppose it's difficult when you build your own projectors and have no figures for it.

You know about the screen size calculator at projector central don't you?

http://www.projectorcentral.com/proj...calculator.cfm

[geneb]

I didn't see "Gene" on the Brand dropdown.

The focal length for the projector is about 120" and that gives me a screen width of right around 110". The major issue with my original design is that I was trying to keep the projectors from interfering with one another - location is pretty important when the projectors are huge.

The new screen will cover 225 degrees of arc (75 degree FOV per projector) and with any luck I'll get it right the 2nd time. I'm using NThusim Pro to do my pre-warp.

The only down side is that it'll be tricky when trying to set up the same screen system for the F-15C, which is a LOT bigger than my little 109F/X.

g.

[ANDYSMITH]

I am speechless...you are my new hero!!!

Andy

[geneb]

Hehehe. Just let me know who the old hero was so I can run when I see him coming.

Seriously though, there's no rocket science going on - just building on what others have done before me.

What kind of 'pit are you working on?

g.