I just got this PM so its time
(come on man !
spill the beans !
I got three gray hairs just from this morning .)
At 11:58 EST on 10-31-06 member extracheese aka Ken PMed me with the correct answer. So I have to declare him the official winner.
Below is a thumbnail of the setup I used. It's taken facing the projector but the screen side is the same flat black craft paper as on the back side. The reason I moved the screen so close to the projector was to demonstrate the neutral gray concept to its maximum potential. Neutral grays run between white and black. The point I was making with this experiment is to show that the percentage of black added to white does not limit the screens ability to accurately reproduce the whole spectrum of colors. As the screen shots show white can be projected from black given enough lumens. I didn't have a 50,000 lumen projector handy so the logical step to use for experimenting is moving the screen closer to the projector.
And yes the out of focus image is caused by the projectors limits on short focus. Given an add on lens the image would have shown very sharp. The other mode of the experiment was to show the ratio of good lumens to bad and how that effects ambient light.
IMO We will always be looking at a ratio of this type. There are a few simple straight forward things we have learned on this forum to date. We have learned how to improve gain at the cost of viewing cone. We have learned that screens can have improved efficiency while appearing darker to improve our perceptions of contrast. And I hope we have learned that the percent of gray in of itself does not crush whites to grays and alter colors. And darker screens with extra lumens tips the balance in favor of ambient rejection not really the correct term a better term would be ambient competition.
I know this example is not the answer to your dream screen to be used in your back yard on a sunny day, rather the point I wanted to show is that it is possible.
The gain of my little screen would be something like .01 or 100 times the light striking it as coming off. That's a waste of a lot of power in order to view in bright lights and I don't suggest anyone do that.
I do hope this helps people visualize this concept that black is just the darkest shade of white.