We almost got rained out again last night, and the structure was a little wet, but we proceeded nonetheless with the test, hung the projector from the top of the dome on the bracket mounted on the threaded rod. I used a grid distorted at the top into a 1920 x 1080 near circle as a test pattern:
The results were terrible. The image almost covered the dome in height, but was sort of pie shape and very narrow on the width, with tremendous distortions and light fall off top to bottom:
So much for my Bourke Paper based vertical projection concept. Christophe had a problem to deal with on the phone, so things dragged on, and Randy had to leave rather disappointed.
Finally, after taking down the projector, Christophe tried HIS more simple concept of placing the mirror in the center of the floor and projecting horizontally, and that actually worked beautifully. The image was in focus all over (a little soft for a still image because of the large area covered, but Christophe could see individual pixels, and moving video should look sharp enough), most of the half dome was covered, there was no light fall off, and distortion was very limited:
The only difficulty may be to get a continuous seamless image where the two projections blend, though I think this may be a built in feature of the software for those projectors . A black background would make it easier of course:
The results were terrible. The image almost covered the dome in height, but was sort of pie shape and very narrow on the width, with tremendous distortions and light fall off top to bottom:
Finally, after taking down the projector, Christophe tried HIS more simple concept of placing the mirror in the center of the floor and projecting horizontally, and that actually worked beautifully. The image was in focus all over (a little soft for a still image because of the large area covered, but Christophe could see individual pixels, and moving video should look sharp enough), most of the half dome was covered, there was no light fall off, and distortion was very limited:
Even the architectural image looked beautiful, with the ceiling edges almost straight and square:
We were pretty excited. There are some adjustments left to be made for sure (squashing the image about 10% vertically, and adjusting the curvature of the sides to fit the half dome exactly), but I am totally confident now it can work. We could build a 6 ft platform in the center of the big 44 ft PTTR dome to put the half sphere mirror with two projectors on it. The VJ's and computer station could go underneath.
My 20 ft half dome looks bright enough with one 5K projector, so the whole 44 ft dome would require (5K x 4) x 2 = 40K . So two Barko 20K would be required(or two new 1920 x 1200 Panasonic 20K's that just came out and are half as big and heavy, and require half as much power as the standard Christie and Barko):
The only difficulty may be to get a continuous seamless image where the two projections blend, though I think this may be a built in feature of the software for those projectors . A black background would make it easier of course:
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