Originally Posted by RobZ
I would think the same but this shot looks pretty good. What gain is the DIY screen?
From the very start, after having posted a Thread on my intentions toward the making of this screen. The Really Big picture Show http://www.avsforum.com/avs-vb/showthread.php?t=854134
..........it was oft stated that it would be impossible for the RS-1 to deliver a decent image at such a size, even if a 225" "High Power" was available. But'cha know, there wasn't many options to choose from, and since most everyone was certain Calbear was SOL, there wasn't much to lose in trying.
My original intention was to use what was called "Silver Fire HG*" *High Gain
Silver Fire was/is originally intended for use in ambient light situations, and the HG derivative was developed for low lumen output PJs that still had ambient "issues' to deal with. As compared directly "side to side" to a High Power Screen sample, the SF-HG DIY mix's gain was estimated at a minimum of 1.6.
That seemed like it would be enough, because what with the RS-1's "honest Injun" 700 lumens, it's actually a pretty bright PJ, so the risk of complete failure was low enough to allow Calbear and myself to give it a shot. Besides, if a SF-HG screen could also work to enhance the perceived "on screen" Contrast beyond 15k, we'd accomplish having the "Best of Both Worlds".
But sometimes things are not what you want them to be.
Upon squirting a 2' x 4' test panel of SF-HG and using a 2' x 4' reference "White" panel, what was noticed was that the lumen levels available would in fact deliver a very bright image with the SF-HG. However, the appearance of the "Whites" on the SF-HG panel was not to Calbear's liking when compared to the pure "White" screen sample. Side to side, the SF-HG's whites looked light Gray.
This came as no shock to me, nor should it to anyone familiar with how any shade of Gray affects pristine white performance. The RS-1 does not have enough uber-lumens to compensate for the White Level attenuation, and basically, neither of us really wanted to tweak the RS-1's gamma/CR settings to the point it "might" compensate.
As one might postulate, reducing the size of the screen wasn't an option either, nor was moving the PJ significantly closer. But I was there (... lusting over his cars and drinking beer...) and a Screen needed 'making'. My past experience with CMRA's "S-I-L-V-E-R" solution told me where to look for more gain and brighter whites. But Gol-Durn it....S-I-L-V-E-R can be a tricky squirt on a "normal size" surface. (...ya know...120" to 144"
) ...let alone a 16' Wide - 9' High Billboard size screen. (Just try doing the sideways "Mississippi Shuffle" across two interconnected 2' x 12's, while keeping your distance and height level constant.
) To err would mean to "stripe" and with a translucent DIY Mix like S-I-L-V-E-R, there is little if no leeway for error.
Calbear looked at me with an earnest AND expectant gaze that told me he was depending on S-I-L-V-E-R to come through.
The first order of business was to accomplish getting a 16' x 9' surface that had NO blemishes. Building a perfectly flat surface was easily enough done using Aluminum Framing and Drywall. But all Kudos belong to the erstwhile and accomplished "Jack of all Trades" Juan Carlos for his "Mop On De Mud" technique (...the entire screen was prone on the floor!) and his "Mouse Sanding" efforts.
With about 6 people helping, the screen was lifted and got hung into place and the squirting commenced. It must be stated again, that I do NOT think the project would have been possible without the use of the "electric" Wagner Control Spray HVLP Gun. It's rate of Paint delivery, the ultra fine spray pattern it produces with a thinned material, all combined with the required technique to create a exceptionally smooth painted surface.
So how much gain does S-I-L-V-E-R produce? To my approximation at least 2.0
or all the commentary about how impossible the task at hand "is" would be obviously borne out by photographic imagery that would not look like the example above. It is most likely 2.2
.....maybe more, but too much speculation without hard data doesn't bode well under Forum Peer review.
But absolutely, it would be great if anyone attending Calbear's "Premier Presentation"
that has the equipment to make such a measurement could bring it along and settle that little bit of speculation.
What really matteres most of all is that the end result would not be any lessor degree of quality than all the rest of Calbear's efforts. After all, "The Big Picture" is the center of attention.
So Calbear got his "Blazin' Whites, and S-I-L-V-E-R's Silver Metallic/Glaze content provided both gain, and some additional enhancement of Color "PoP" and CR. All of which easily and effectively compensated for both the size of the Screen itself as well as the distance the PJ had to be mounted from the screen (27' I think?)
To be involved in any way with Calbear's project is/has been a distinct pleasure. Meeting the Wife and extended Family, and cookin' BBQ for 'em was a delectable treat.
For dessert, I really want to be there when he cuts the "Ribbon".
Be sure to check in before you start to trim off those Fiber Optic lines.