This was posted into another thread but is also a good example for this thread and a bump for any newcomers.
First off let me say welcome to the forum, and your screen undertaking both size and environment are commendable. With results very impressive.
Keeping with the new request for subjective comments only I will try and comply.
I took the liberty of capturing your photos off line and tried to rearrange them in a manner that shows what is happening on your screen in terms of real CR and perceived CR, the effect of the ambient light, the screen and the brightness of the projector. I have shown such things before with more of a numerical method but your excellent photos allowed me to show this in more of a graphic manner that doesn't need one to analyze numbers.
What I did to your photos was ONLY crop and cut and paste. I didn't alter one pixel as to brightness or color information.
Your first photo of the full space shows a full range of CR within the photo the spotlights are pure white and the blacks behind the curtains is almost pure black. So depending on the monitor everyone is using to view this image it shows the best CR their equipment can show.
If we look at the projected image of the city and measure the difference between black and white (much the same as what your eyes saw in person I'm sure) that CR would be in the real range of less than 10:1 would be my guess maybe lower. But our eyes and brain allow for perception and show us a much improved image than if the wall was white.
If I were ask everyone in the above image to find the black building on the right hand side of the screen about 2/3 of the way down they could all find it. See blow up below.
And now asked you by eye looking at the black building and the different wall colors to the right of the projected image, what one is close to the black color of the building?
First is the band the projector is masking black plus the ambient. The second is the ambient lit wall. And the third I think is the wall being shadowed by the curtain.
OK has everyone picked a match for the black building. I cut and pasted the building to each different band to remove the influence of the contrasting image around it to make comparison easier to see.
And then a bigger blowup.
I'm not trying to draw any conclusions about anything here except your photos were great at pointing out perceived contrast and gray nature of the paint you used aided in that. How it would have compared to the same shade of gray without the metallic we don't know. And we don't know if the projector would have had enough lumens to support the gray without the metallic. Your off angle shot shows a nice image from the side seats equally as bright. So something ether the wall texture or the paint or both are causing wide angle dispersion of the image. Could you have even went darker with the screen and saw more perception improvement we don't know that ether.
But for a 100 buck and a block wall, I have to say I'm very impressed.
I hope you stay active in the forum, as I read your other post saying this was a one time paint project.