Well, summer finally ended and I found the time to re-paint my screen. I'm also remodeling our basement/entertainment room/Home theater. This thread will chronicle that effort and hopefully provide a bit of new information. A couple of disclaimers first. When i compare this screen to my prior efforts, I am comparing it to just that, MY
prior efforts. I am not making blanket statements about one formula or another.
I started investigating white screens because I just wasn't getting the brightness I needed out of gray screens. Realistically, I should have gone with a smaller screen, more suited to the output of my projector. Oh well! Also, bear in mind that my room is semi-treated--remodeling will bring it back to fully treated--with zero ambient light during movie watching. White would not work near as well in an un-treated room with ambient light.
My first effort began with trying to develop my own screen paint formula. A more difficult task than I had imagined. I came up with something rather complex, and had some promising results. The promising results were tempered with a few problems though. To gauge my success, I researched what might be the best OTS white paint I could find. I came across the Glidden Diamond 450 Titanium White which I learned was in fact the exact same paint as the Dulux Light and Space Titanium White that is so well thought of in Europe. The Glidden was so close to my own paint formula in brightness--and devoid of negatives as well--that I realized it was pointless to pursue my own formula. Plus it is OTS and rolls or sprays like a dream!
If you're going to go with a white screen--as opposed to gray--you are after brightness first and foremost. So, if one white paint is brighter than another white paint, is at least as neutral and does not hot spot, it is a better paint. (Assuming equal ease of use.) Lots of people use the Sherwin-Williams ProClassic Smooth Enamel Satin Extra White because of an article online at Projector Central. So, obviously, it made sense to test that paint as well. Using an i1 Pro and both BabelClor and HCFR software, I analyzed both I analyzed a few other screens as well--including the commercial screen : Carrada Brilliant White 1.4 Gain and Behr 1850 UPW. Here are the results of the analysis of those four screens. (I understand that Behr has changed their formula, so that result is really invalidated.
The first number is cd/m2 with the sensor adjusted for maximum reading. The second number is cd/m2 with the meter lowered about 25 - 30 degrees. the third fourth and fifth numbers are the RGB values. The last number is deltaE from perfect neutral. A deltaE of less than 1.0 is considered perfect. Less than 3.0 is considered to be so close as to be indistinguishable from neutral by the human eye, at least according to what I've read.
Glidden Diamond 450 Titanium White:
36.35 31.6 245,246,243 1.43
Sherwin-Williams ProClassic Smooth Enamel Satin Extra White:
31.25 29.5 240,241,236 2.58
Carrada Brilliant White 1.4 Gain:
36.1 30.8 242,242,236 3.22
Behr 1850 UPW:
35.3 32.05 249,249,246 1.95
One note: This really opened my eyes. Comparing the Behr and the Glidden visually, I would have said the Behr is slightly brighter. The slight color variance can fool the eye; it really truly takes instrumentation to tell the tale.
Visually, I can detect absolutely no hotspotting with the Glidden, Behr, or SW. The Carrada sample is too small for me to really tell.
Personally, I think the Glidden and the Behr are both better choices than the Carrada BW sample I have. Similar gain characteristics and more color neutral. I'd give a slight nod to the Glidden over the Behr, and I'd rate the Sherwin Williams a distant number four. Distant at least when you consider how close the top three are.
So, here are my ratings:
#1 Gliddon Diamond 450, Titanium White, Velvet Matte
#2 Behr UPW 1850, Interior Flat Enamel
#3 Carrada Brilliant White 1.4 Gain Manufactured screen.
#4 Sherwin-Williams ProClassic Smooth Enamel Satin Extra White
BTW: I did do reflectance curves of all the white paints, they are all equally good with the Behr being the brightest white, N9.78. I was just too lazy to save the graphs.
So because of this analysis I decided to paint my screen white with the Glidden. I also encouraged it's use over the SW. I was called on that--rightfully--because I had never actually seen a full screen done with the Glidden. Now I have. So how does my subjective analysis compare to my instrumented analysis? Well, I can best sum up my impressions thusly: WOW!
The straight on shot of the screen was done with a flash to demonstrate the lack of hotspotting. The screenies are of an 8700UB hitting the 138" screen with a measured 440 lumens. I'm hitting it with 1200 lumens now and it's even more WOW.
The Screen is amazing: we watched Avatar again with my new "Light Power Edition" 5020 and this screen. Wow, wow, wow. Not a hint of grain, shimmer, or hotspotting. Just a crystal clear image. My wife--who is not sensitive to such things and swore she'd never notice a difference--was stunned by the picture. She absolutely raved about it. Of course, she was seeing the combined effect of the new PJ and the new screen. The overall improvement--considering both the upgraded PJ and screen-- feels like as much as when we went from SD to HD. Seriously, it's that good.
After getting a 5020, I was thinking I would paint the screen gray because I'm getting 1200 lumens in ECO mode, but I'm absolutely stunned by the picture. Over 20 ftl... Brilliant whites and gorgeous deep blacks. Best picture I've seen yet on a screen. I think I'll be leaving it white!