CMRA's S-I-L-V-E-R solution starts here: - Page 15

Ryan,

You've nailed it. The reflected light from that ceiling is what's affecting your Blacks. S-I-L-V-E-R is zapping the ceiling with reflected light, and in turn is zapped.

Try this....adjust your lens shift to the lowest level you can to increase the distance from the top of the image to the ceiling. Do this with a paused image containing some real blacks. If you have enough vertical lens shift adjustability, you'll see a difference.

Does anyone know if i can use my old Wagner airless spray gun?
Y have tried it (with a highly diluted mix) and the result is OK. I am wondering how better my screen could be if I trie the Wagner CS.
Is the Wagner CS the only way?

Thank a lot

Well..............it's pretty iffy advice to suggest that a larger nozzle, bulk sprayer Gun like the older Wagners would do S-I-L-V-E-R justice. This application requires several exceedingly thin coats that "gradually" build up translucent layers that each contain diluted amounts of Silver Metallic. As they build up one on top the others, gradually the visual concentration of SM particles increase, filling in empty spaces left between previous coatings.

An older Gun might be (...has worked at times....) Ok to lay down diluted coats of a normal, "dense" paint, and keep it under control enough to effect a nice smooth coating. But the degree of control a Gun like the Wagner CS provides due to it's "HVLP" (High Volume-Low Pressure) design that almost completely atomizes the paint as it leaves the nozzle is pretty much worlds apart from other, more basic Wager designs. That's why I was never a "Wagner-ite" until a fellow member told me of that new developement.

I've never used my $700.00 Comp/HVLP Rig since.

But here's your possible out. When you mix up S-I-L-V-E-R as directed, you'll wind up with almost 3/4 Gallon of Paint. That's loads more than most need unless doing a gargantuan sized Screen. (...and who ever does that? ) So you can getcherself a piece of Thrifty White Hardboard @ Home Depot ($11.95) and give it a try, using the spraying technique as outlined within this thread. If it's a bad result, no worries. (well...that is the price of a Premium Six Pack and Doritos) You can always switch to the Wagner CS and geterdun.

Well that's a "Duh" moment, Camera man! I've seen your set-up, and fur shur...., without that masking Paper, your screen would look appreciably washed out. As it stands now, by masking off the WHITE ceiling, (...and the Side walls too, don't forget...) it looks splendid, even with some ambient light leaking in around the Window shades.



Yeah. I live by the Rule of the Delta SkyMile. That's Ok...it still kicks as a great Tire Inflator.

What's the gain of S-I-L-V-E-R paint?. How does it compare to the Dalite High Power in this area?.

Yes, it is god to know what is the REAL gain of that promising screen.

At present only HE knows for certain.

But a recent showing to some very learned AVS'ers of a 225" example placed the "estimated" Gain at between 3.0 to 4.0.

If true, thats an incredible feat for a DIY screen to acheive, while maintaining a decent viewing cone and not producing any degree of overt Hot Spotting.

However that estimate is not as of yet validated by an actual measurement, but that is forthcoming.....soon hopefully....for the mere mention of such a spec. can cause quite an uproar if it's not confirmed.

And one must consider that I determined that because of the size of the screen, and the distance of the Throw of the PJ (27')....and the low lumen rating of the Pj in use (700), I applied a more densly packed coating that would be otherwise suggested of a more reasonably sized screen. This served to increase the gain considerably beyond the already determined 2.0 level.

Considering that comparisons made to a DaLite HP suggested that a normally done S-I-L-V-E-R resulted in it being judged as being entirely comparable in gain to the former (2.8) there can be no large difference in play.

So if one was to err conservatively and state that S-I-L-V-E-R comes in at 1.8 / 2.0 gain average, depending upon the amount of paint applied, and the effectiveness of the underlying substrate (bright white)then such a statement is not in danger of being labled as an excessive estimate.

Basically, the gain acheived will be determined by the manner in which the Screen is made. Someone else hase made a S-I-L-V-E-R, tested it in the approved manner, and then posted a Gain figure of only 1.4 but since the making of that example was not itself validated as being correct, that determined figure is not really dependable as it does not jive with the results so many others have acheived.

The 225"er was squirted by your's truly, so when that figure is published, I'll stand by that result....high or low.

Until that occurs, you'll have to make your own determination based upon examples like the ones below. Remember....225"s diagonal ......27' throw.....700 lumens
.....you don't see the results shown below with a screen size that huge that only has a gain of 2.0




....and here are some ones in total darkness.









.....and these last two in almost complete darkness....but not quite.

Hi all,

I've been a voyeur on this site for a few weeks now grabbing knowledge that you all so kindly share with the masses. I am totally new to the projector world but when we decided to finish our basement I wanted to get the biggest screen possible at the lowest price like us all on here! Picked the optoma hd65 about a month ago and since then have been struggling with what to do about a screen. Our room by the way will have a couple of scone lights on during viewing and quite possibly a lamp on by the seating area also which will be about 18 feet away from the screen. I am planning on a 133 inch 16:9 screen. I first thought that laminate might be an easy and effective way to go until I read about RS-maxxmudd and was stuck on that until I read about Silver and now I am just a little CONFUSED! I thought I might lean on the good people on here to give me some direction on what may be the best way to go for my application and projector. My best beer drinking buddy is pretty handy with a paint sprayer so I am able to apply the paint that way if needed.
Any suggestions or help would be greatly appreciated.

If true I agree, that would be incredible. Especially with the nice wide viewing cone SILVER has... to have that wide of a viewing cone and if the gain really was 3.0-4.0 that would be amazing.

Just out of curiosity (and not an uproar) but how did you come to the estimated value of 3.0-4.0? We measured SILVER to have a gain of around 1.36, so it would be fair to round up to 1.4

I'd have to say that's pretty accurate too because so far all of our gain tests have been dead on with every known commercial screen and what they are stating as their gain. All the gear is calibrated and testing is industy standard.

Don't get me wrong and go off or anything, 1.3-1.4 is a very respectable gain, especially with DIY. I just had to jump in though because I don't know how you came up with 3.0-4.0. If it was a guestimate by eye, that's understandable but also shows how much our eyes can fool us and aren't an accurate way of determining things like this or even color balance... but not to worry, SILVER doesn't have a bad color balance either. It's not dead on D65 neutral, but also isn't out of the range of good screen, especially for a lighter shade screen.

I do see where you mentioned the 1.4 gain value but stated an opinion that the screen wasn't made correctly or validated as being correct. All the directions were followed so it really should be representative of the typical results others will get. Of course you are right when you state if a different substrate is used or different base, it could affect the gain, but it isn't going to be that big of a difference, not a 2.6 increase in gain.

Someone who has done a quality S-I-L-V-E-R screen needs to get a sample of the Dalite High Power and compare. Providing the projector is positioned correctly it will tell you instantly which has the higher gain. That's what I'm interested in, more so than the actual measurement.

The problem is that these two screens work in totally opposite ways so in real-world situations there can be no fair comparison in relation to gain. The High Power is retro-reflective (light is reflected back toward the source) and the S-I-L-V-E-R screen is specular reflective (light is reflected away from the source).

Another problem trying to pin a specific gain figure to a S-I-L-V-E-R screen is that due to the mixes nature two screens will rarely be the same. The criteria for making these screens is lax enough (not necessarily a bad thing) that no two screens would be alike unless more stringent protocols were put in place.

S-I-L-V-E-R is especially susceptible to varying gain from screen to screen since it is a layered application. The mix is simply a given amount of mica-based silver paint mixed in a given amount of clear medium. The percentage of silver paint to clear medium is quite low (from 5% to 10% if I understand correctly) which means the mix is anywhere from 90% to 95% clear medium and the screen must be built up spraying layer upon layer until the desired affect is achieved. One layer too little or one layer too much will change the gain of the screen. How much is open to conjecture.

It was indeed an estimate, made by a couple individuals in attendence who have enough practical experience to venture such a determination without being too far off the mark. But as stated, it was an estimate, made by consiering the size screen, and the PJ's luminosity output and throw. What really thew everyone for a loop was two things....how bright and effective the huge thing was under ambient light, and how considerably wide the viewing cone was despite the apparent high gain. A lot of head scratching went on....I'll tell you that !


No, I didn't say it wasn't made correctly, only that I could not validate how it was made and if the measured gain was truly representitive of the application's potential. I didn't dispute the figures obtained either, only that they could only represent that particular effort, and therein should not be offered up as being definative of all such S-I-L-V-E-R s Some efforts, like the one above could be considerably higher in gain, while others might not make it much over 1.0

And really, that makes sense because in DIY, things are bound to vary to some little or large degree. In the tested example for instance, if the Screen was made exactly correct, (...most likely was...) and a gain of 1.4 was measured, that in and of itself is an accomplishment when accompanied by such a wide viewing cone.

I do beleive the reason the viewing cone is so good is that the properties inherent in the multi-layered translucent Glaze coats work to scatter a good deal of light comining from off the reflective particles, all the while as those particles are also directing a perponderence of light directly forward. Sort of the same thing as Light Fusion, but with the effect all contained within the Surface instead of coming from a complete penetration of light through the paint, and the subsiquent mirrored reflection and re-fusing of attenuated light with the original image. The latter helps maintain gain, the former (S-I-L-V-E-R) does far more to actually increase gain.

And in review, I did state that instead of using the 95% Glaze - 5% Silver Metallic formula, I had upped the SM ratio to 10%. I also did a heavier coating (IE: A MORE DENSLY PACKED AMOUNT OF SM THROUGHOUT, BUT ESPECIALLY NEARER THE SURFACE) than a normal S-I-L-V-E-R would receive, knowing that the incomong light would not be nearly as high in level as normally encountered. Both would serve to increase the normally realized Gain potential S-I-L-V-E-R would usually provide.

All of that factored into the estimate that was made. And it was an estimate that in no way should be construed to being applicable to a normally configured S-I-L-V-E-R.

I hope that helps to quantify my previous remarks


.

Well, that is eactly what was done, and the results reported. However at the time....and still in the present....it seemed a bit "risky" to hearld such news as being completely precise, so we simply moved the figure downward to to 1.8 range. The subsiquent test being refered to above came up with 1.4 gain.

So in fact, the explination I gave above does in some ways relate to the more normal version of S-I-L-V-E-R used in the "comparison" test. Viewed directly from the front, S-I-L-V-E-R was completely comprable to the HP. Viewed from the side at a point where the gain from the HP dropped of considerably, much more so than the S-I-L-V-E-R , it seemed to point out that the S-I-L-V-E-R must in the very least be producing the same amount of gain, if in fact actually more if the common formula of Drop-off percentage was considered.

So all of that presented a quandry...and mystery of sorts. And being so mysteriously unexplainable, it seemed wise to embrace a much lower figure that while still high, was more in keeping with conventional wisdom and acceptable levels.

As many others, I must await precise gain figures on the above screen. But in the same respect....it's a "One Off" example, so what it represents is potential, not conventional and normal results.

....but at least we all know it shows pretty clearly what CAN be done, and that is something exceedingly exciting of note.

A quick post note made after I posted and then read Harpmaker's own missive;

I'm just too slow on the Draw being so slow on the Keys. While I slowly respond to wbasset's reply, (almost 90 minutes of stroking keys) Harpmaker has said almost the same things I was trying to relate....only in shorter verse. Once again, my "Hunt & Peck" efforts have come up lagging in the race to post up in a timely manner.

Yet another post script;

Actually, and as related in my comments, S-I-L-V-E-R seems to be both screens rolled (...well, sprayed really...) into one, and do both things at the same time. Hence the quandry as to how to measure and accurately describe what is going on with the crazy thing.

Anyone who knows my typing speed knows I simply could not compose all of the above in the time frame shown after Harp's own posting and my own. It's flat out impossible! Crikey! It took me almost 20 minutes just to type my two Post Scripts!

.

.

To quote the Immortal Bard, "Brevity is the soul of wit."


At the great risk of being pummeled unmercifully for bringing too much science into things, S-I-L-V-E-R cannot be retro-reflective in the slightest way since none of it's components are retro-reflective. S-I-L-V-E-R (and all other non-retro-reflective screens) exhibits a combination of specular and diffuse reflection, with most of the reflection being diffuse otherwise it would hot-spot very badly. When S-I-L-V-E-R is sprayed, every layer applied will increase the specular reflection of the final screen.

Specular reflection is like a sheet of highly polished metal. If you shine a flashlight straight into it it will reflect most of that light back at the flashlight, but if you angle the flashlight most of the light will be reflected off the surface at the opposite angle at which it strikes the metal.

Diffuse reflection is like a pile of talcum powder or cornstarch, no matter what forward angle the light from the flashlight strikes the powder it will be reflected at all angles equally.

Retro-reflection is rare in nature, the primary example of it is the light reflected back from a person's or animal's eyes when using a camera flash. It doesn't matter at what forward angle the flashlight strikes the surface, most of the light will be reflected back toward the flashlight. Retro-reflection using glass beads (such as in the High Power screen) isn't 100% efficient so some light is reflected off the prime axis; also, the glass beads on the screen have a white surface behind them which is exhibiting diffuse reflection which makes the screen work (although far from it's best) when a projector is ceiling mounted and the viewer is sitting.

It isn't difficult (after one gets the proper measuring devices) to measure screen gain, but it is time consuming.

You'll be able to see if one is brighter than the other but that's also a tricky topic as you mentioned. The HP is a retro-reflective screen and SILVER is an angular reflective screen. Set the PJ high, and the HP won't show optimal, set it low and then the SILVER won't be optimal... it's hard to compare like that but I understand what you are saying.

The thing about gain and color balance is our eyes and brain try to auto correct, plus everyone sees things slightly different. That's why going solely by eye can't be done. At least not accurately.

Actually SILVER and Designer White were pretty close to each other, with SILVER having a slightly higher gain and slightly lower viewing cone. Where SILVER really 'shines' in my opinion is with larger size screens that exceed the sheet size of the laminates. The 1.4 gain and ability to spray it large make it a great option for anyone with the patience and skills to make it work.

Gain is just a tool to achieve the recommended fL for a specific setup. It's not a control knob or the end all beat all spec. Whatever gain may work for one person and setup may be totally horrible for another person's setup. Now color balance is universal, but as I mentioned SILVER isn't bad, it's not dead neutral but still a very viable screen option if you have the skills to make it.

I think one of the 'missing' or 'overlooked' factors in this whole gain discussion is midtone support. When you have a brighter screen with good contrast, it is usually easier to identify the differences between midtones. With that fact in mind, if one screen shows the differences between midtones better than another, (and they are not side by side) the eye assumes it must be brighter, because the brain associates (past experience) brighter with the ability to differentiate midtones. (at least that's my guess.....) And that causes people with a LARGE amount of screen viewing history, to assume a gain, that the measurements may not support. In other words, it's not 100% about how white the whites are, or how black the blacks are, but how easy it is to distinguish between two very similar shades of the same color.

With that being said, I'll attach a picture that I DO NOT WANT TO START A WAR with. So, please any comments directed at this picture, be polite...

This is a picture of a draper luma 1.0 gain, in front of my painted concrete block wall. By eye, I'd say both are close to the same gain, and it's possible the draper may even measure higher. (not sure how it couldn't 'measure' better considering the texture of the block.) However look at the circled trees.... It's all about the trees in this picture. On my laptop screen all of the trees have definition, and do not look like a green blob. On the draper, it's green mush, on the concrete block, it is not. Gain of the block up or down vs the draper -- it's easier to view the block, (wow, how weird is that to say...) and that is the surface I'd prefer to watch 50' away.

Wouldn't centring the projector with the screen, no v/h offset, cause the SILVER screen to reflect it's full gain axis back to the projector thus aligning it with the full gain axis of the High Power sample?.

Three years ago I sprayed my wall with the Mmud mix and was very happy indeed. With my BenQ PE7700 zero offset DLP projecting from the ceiling at a 118" screen and a fading lamp, I was excited at the prospect of higher gain and contrast (pop) in my totally light controlled room.

The results are very pleasing. One thing to mention is that the wall (surface) must be completely flat. The wall protrudes ever so slightly which is located about 3/4 across the screen and about 3' down due to a stud. With the new screen, this has caused a "shadow" to the right of the stud visable during light colored scenes. The shadow disappears as you go off axis to the right. I have some minor hot spotting in the middle of the screen towards the top but this does not affect viewing.

Thanks to the original poster and to MississippiMan.

Looks like I might have a new formula to spray on my wall later this year! Thanks, guys.

Hi Scoob!

Hows every little thing in Joisey!?! Your Post is a great "Welcome back" to see upon returning from a long "Butt Buster" of a plane ride!

At least I know your no slouch as far as wanting something special, and being willing to do what it takes to get it.

Don't be a stranger....besides, I'll be back in Wayne, NJ soon and it would be great to hook up witcha!

MMan

PS, Isn't almost everyone in "Joisey" alien?

Naw....., he said "later on this year". That implies within another 3 months, 29 days on the calendar.

[quote=MississippiMan;16929269] 3 months, 23 days

I must say WOW,WOW I built this screen for my Sony hw10 and it makes the pics jump out atcha. Truly a wonderful screen I highly recommend, and no hot spotting to note. I did do one different thing tho I made mine out of canvas instead of sheet rock. I went that route cause I do things on my own pretty much and the gysup board was to heavy to take up the stairs. And the screen is 120". Anyway colors are vibriant and 3D like. Thanks for this thread!!!!!!