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Discussion Starter #1 (Edited)
Okey dokey. Thanks to a lot of great help, both here and at the "other" forum, I think I'm close to a solution for my needs. This is a niche screen for sure. I'd say for a 122" screen or smaller WA DW would be a of a lot easier. But for a white 123" to 138" screen size, with a bit of gain thrown in, Titanium Sintra shows a lot of promise, at least for me! :)

This is not ready for release, I need more testing and feedback.

What is Titanium Sintra the solution for? Dark, light controlled rooms combined with a PJ that doesn't have the output to go gray. Ambient light only for casual sports viewing, dark for movies. All ambient light for sports comes from the side.

My screen is 138". I tried 3 full sized screens. In order of appearance: SF V1 2.0, Bare Sintra, and SF V2 HG. I've tried swatches of C&S V1. I have an Epson 8700UB PJ, and I want to run it in THX mode, not Dynamic or Living room. (What's the point of a color neutral screen if you hit it with inaccurate color?) So I've got around 550 lumens to play with. My first screen, SF was too dark. My second screen, bare Sintra, was bright enough, but boy did it hot spot. Even though it was white, ambient performance was just fine with me. Movies in the dark were stunning, except for the severe hotspot. One other con, a little sharpness was lost on the bare Sintra. My third and current screen, SF HG, hot spots. Out of the hotspot it's marginally bright enough. My Swatch, C&S V1, seems to be a match for the SF HG but without the hotspot. Marginally bright enough, good ambient performance for my situation. But what about as the bulb dims?

I decided a translucent coating for Sintra was the direction I needed to go. Something to tame the hotspotting, but keep as much gain as possible.

First I tried spraying Sintra with Liquitex Fluid Matt Medium. Seemed promising. I put up the swatch a few days later, still some hotspotting. Then I tried sanding the Sintra with 400 grit sandpaper, then spraying with the Matt Medium. Zero hotspotting, but a blotchy look under PJ light. No good. then, two weeks later, I mixed 4 parts Fluid Matt medium with 1 part Titanium White Basics--NOT Matt--and 1 part water. Still some hotspotting, but not as bad as the sintra with Matt medium. So I compared the mix swatch with my original Sintra with Matt Medium. Surprise! The original sample no longer hot spotted. The medium needs at least a week to cure, maybe more. So I waited a week and retested the mixed sample--4 parts Medium, 1 Part TW Basics. Hot spotting gone. And WOW, I love the performance. Color tests and screen shots to follow.
 

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Discussion Starter #2 (Edited)
Heres the color tests of Titanium Sintra (TS) and some other samples. Testing was done with an Eye1 Pro and BabelColor. (Trial version.) The curves were done at D50 Illumination, because of the trial version limitations. The RGB values were done with D65 Illumination.

The RGB values are for: (Left to right, top to bottom.)

Titanium Sintra, Bare Sintra, Sintra w/Matt Medium, Cream & Suger V1, Silver Fire V2 HG

The Black line in all of the curves is Titanium Sintra. The red lines are, from top to bottom:
Bare Sintra
Sintra w/Matt Medium
Cream & Suger V1
Silver Fire V2 HG
 

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Discussion Starter #3 (Edited)
The background screen is SF V2 HG. The panels are from left to right: C&S V1, Titanium Sintra, Bare Sintra. Note the hotspotting on the SF HG and the bare Sintra. Also note that the Titanium Sintra is just a bit brighter than the bare Sintra as soon as you have even a tiny angle. BTW, the moire you see is not visible in person, just in these pics.
 

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Discussion Starter #5
Ambient performance. The two Panels are Left to right: TS and bare Sintra. Note the ambient performance of TS is identical to bare sintra, but inferior to the background SF HG. The bottom picture is a screen shot from a bare Sintra screen in ambient light. Plenty good enough for me. All ambient light is sufficient for reading--if uncomfortably--at the seating position. Left of the screen the curtains are open and bright lights are on over a pool table. Typical sports viewing/party conditions. PJ output has been increased to Dynamic in these shots.
 

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Discussion Starter #6
Light controlled screen shot. TS sample against SF HG background. Notice at the lower right of the sample, the darks are virtually indistinguishable between samples. At the top of the sample though, the sky above the tree is far brighter on the TS. BTW, for reference, my C&S V1 sample has identical darks to my SF HG screen.
 

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Discussion Starter #7 (Edited)
Subjective impressions. With the TS sample up and watching a movie, the TS is like a window. Clear, bright and lifelike as you look through the window. I'll be redoing my screen with TS sometime in the next month or two; it might have to wait till after the holidays...

I have no idea what the gain is. It seems to me that gain is slightly higher than bare Sintra outside of the hotspot, and much higher as you increase the viewing angle. So, any guesses as to what that would make it?

Input?

Thanks!

Edited to Add: BTW, the slight loss of sharpness seen with bare sintra is NOT seen with TS, or with any of the other samples above.
 

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Thanks Nak, that was a very nice presentation! :clap: It shows a nice example of what hot spotting is and why it should be avoided.

Mech's smaller samples of Sintra didn't hot spot, but your Sintra clearly does.

It's good to know that the matte medium you used cures to a point that it doesn't hot spot. I do have a question, Liquitex doesn't make a medium called 'Fluid Matt Medium', but Golden does. Could you clarify which one you used?

I honestly don't want this to sound negative, but for the record your C&S™ test panel was off-color and darker than normal. I'm not saying you were at fault here, it very well could have been the base paint was off. Do you remember which C&S™ formula you used (1, 2 or 3)? No big deal, I'm just curious.

Did you test your Titanium Sintra against one of the 'Ultra White' paints?

Again, well done. :T
 

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Discussion Starter #9
Thanks Harpmaker!

I noticed that about the C&S; I'm not sure why it's like that. It's the first formula (#1), and it was definitely the old Craftsmart paint??? I fast dried it with a propane heater; perhaps that caused the difference? Maybe Craftsmart changed the paint before they changed the label...

It's actually called Matt Medium, it's one of Liquitex's fluid mediums.

I haven't compared to an ultra white paint. That's next, along with a WA DW sample. My understanding is that the white paints have a gain of around 1? I'm hoping for 1.3, but who knows? I can't test gain, but a comparison against the WA DW should give me an idea anyways?

My goal was to get equivalent ambient performance and dark performance to bare Sintra, as I was really happy with that, without the hotspot.
 

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Thanks Harpmaker!

I noticed that about the C&S; I'm not sure why it's like that. It's the first formula (#1), and it was definitely the old Craftsmart paint??? I fast dried it with a propane heater; perhaps that caused the difference? Maybe Craftsmart changed the paint before they changed the label...
Several things could have happened to get the off-color C&S™ #1 mix, neither of which would be any fault of yours. That version of C&S™ was the first to be discovered and used a base color from Sherwin-Williams called 'Luminous White'; that base, while not totally discontinued, has been replaced by a base called 'High Reflectance White' in many SW paints. It is very possible that even though you asked for Luminous White you were actually sold High Reflectance White which would cause the blue push to the final mix IIRC. The other thing is, as you pointed out, the silver paint itself could have changed while still being sold in the same bottle design and stock number. This possibility is the main reason we dropped Craft Smart Metallic Silver from any future mixes - you just can't count on any "craft paint" having a consistant color or metallic content from batch to batch. It's too bad to because the old CSMS had some fantastic reflective characteristics. I doubt drying it with a heater made any color change in the mix, it could, however, cause cracking due to the paint drying on the surface while the bottom was still very fluid. I've had that happen when I force-dried a sample or put paint on too thick.

It's actually called Matt Medium, it's one of Liquitex's fluid mediums.
Thanks for the clarification. :T I'm sure you already know this Nak, but to those folks reading this and thinking of trying something similar themselves, be SURE to stir the Matte Medium thoroughly to get an even matte finish. The "flattening agent" added to the medium will separate out and fall to the bottom of the container over time.

I haven't compared to an ultra white paint. That's next, along with a WA DW sample. My understanding is that the white paints have a gain of around 1? I'm hoping for 1.3, but who knows? I can't test gain, but a comparison against the WA DW should give me an idea anyways?
Trying to determine gain by visually comparing two different screens is tricky at best. The problem is that many things can affect how we perceive brightness and contrast with the human eye. You can tell which screen looks the brightest under a given set of conditions, but saying that screen has more gain than the other one... well, maybe yes and maybe no. To be SURE, you have to measure the gain with proper instrumentation. Take a look at the image below, it's very clear that the squares marked A and B are two different shades of gray and that B is lighter than A so it must have more gain right? Nope! Squares A and B are the exact same shade of gray (RGB 107, N4.5) so if their gloss levels are the same they would have the same peak gain.



My goal was to get equivalent ambient performance and dark performance to bare Sintra, as I was really happy with that, without the hotspot.
I think you will find that the 'Ultra White' paints such as Valspar Ultra Premium interior latex enamel and Behr Premium Plus will achieve that goal, but it would be very interesting to see one or the other in direct comparison to the Titanium Sintra.
 

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Discussion Starter #13
I painted a 1' x 4' sample of Sherwin-Williams ProClassic Smooth Enamel Satin Extra White. I found this article: http://www.projectorcentral.com/paint_perfect_screen_$100.htm , so it seemed like a good first choice. I'll add the color analysis and screen shots later, when I have more comparisons. Long story short, good, but not as good as Titanium Sintra. Color neutrality virtually identical, Blacks dead even, Titanium Sintra has brighter colors and whites. By a fair margin too, very noticeable. Ambient performance appears to be identical.

Comparisons against a super secret white paint, WA DW, and Carrada BW coming.
 

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Looking forward to the future comparisons Nak! :T

I will have to admit to being disappointed by that article at Projector Central since they did almost everything "by eye" without bothering to do any actual objective testing with instrumentation . I know that most people will say "hey, I don't watch my movies with a colorimeter or spectrophotometer beside me, it's what MY EYES see that is important to me!". While that is a true statement, the human eye makes a VERY poor colorimeter or light meter. The author said "... the Behr imparted a more obvious color imbalance, biased toward blue"; I find that quite interesting since NO sample of Behr white paint that I have ever gotten has ever pushed blue. It has always been extremely close to the Valspar Ultra Premium enamel white (so close they are interchangeable in a screen mix) and both whites have always measured "warm". It would have really helped for PC to have included at least CIELAB color data, if not a full spectral chart, to back their claims.

One more thing to clear up about that article. Speaking of the difference between their StuidoTek 100 and the ProClassic Smooth Enamel Satin Finish screen they said "A spot meter confirmed what we could already see--white highlights were brighter by about 10%, and blacks were blacker by about 10%". The reason why this could be is because the SW 'Extra White' color is NOT an "ultra white" paint, but is a very, very light gray; this would give deeper blacks over a bright white screen. The added whiteness (or rather brightness) would be due to the SW paint being a satin finish having more gloss than the matte StudioTek thus more on-axis gain.

And I still say they couldn't actually detect a +- 10% brightness change with the naked eye. ;)
 

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Discussion Starter #15
Good info Harpmaker, thanks!

The SW paint was 94 L on the L*a*b* scale; my understanding is that makes it a n9.4 shade? Or am I off base there? For an off the shelf white, it wouldn't be bad I think. Even though it's a Satin finish there is absolutely no hotspotting on it. Like I said though, the TS is obviously brighter. For my purposes that's important; I'm trying to wring every last ftL I can out of a screen. What white paint would you reccomend I compare? I'm thinking of mixing up some C&S Ultra, just so we can get a good reference against a known quantity. On the C&S Ultra, is that the matt Liquitex silver basics? On the other hand, perhaps the comparison against the WA DW and the Carrada BW will be enough. One white against another...
 

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Good info Harpmaker, thanks!

The SW paint was 94 L on the L*a*b* scale; my understanding is that makes it a n9.4 shade? Or am I off base there?
It is also my understanding is that the Munsell N values are the CIELAB L* values divided by 10; in fact, I just read that again somewhere, but forget exactly where (I read too much - one link leads to another and that to another...).

For an off the shelf white, it wouldn't be bad I think. Even though it's a Satin finish there is absolutely no hotspotting on it. Like I said though, the TS is obviously brighter. For my purposes that's important; I'm trying to wring every last ftL I can out of a screen. What white paint would you reccomend I compare?
All of the "white" paints (called 'Ultra White' by a few brands) I have measured have all been around N9.7 regardless of brand (including Liq. BASICS Titanium White). The most neutral white I have measured was Glidden Premium (from Home Depot) with a CIELAB of 96.42, -0.83, 0.72. The brightest was Valspar Ultra Premium 'Ultra White' 97.59, -0.78 , 2.53. In my experience it would be very hard to tell these two screens apart in side-by-side testing accept for the Valspar being warmer in color.

BTW the readings I have for white commercial screens are:
Stewart SnoMatte/StudioTek 100 gain 1.0: 96.07, -0.96, 1.76
Stewart StudioTek 130 G3 gain 1.3: 94.85, -0.82, 3.59
Stewart UltraMatte 150 gain 1.5: 94.76, -0.59, 2.97

The brightest target I have ever measured was a block of magnesium carbonate at 99.60, -0.69, 3.31.

All our specto readings are at a D65 white point using a 2° Observer.


I'm thinking of mixing up some C&S Ultra, just so we can get a good reference against a known quantity. On the C&S Ultra, is that the matt Liquitex silver basics?
C&S™ Ultra uses the regular satin finish BASICS Silver.

On the other hand, perhaps the comparison against the WA DW and the Carrada BW will be enough. One white against another...
It's probably best to compare whites to each other and C&S™ Ultra is a very light gray, but whatever you choose to do is fine with me. :T
 

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Discussion Starter #17
Got my WilsonArt Designer White sample today... Wow, not really impressed. VERY color neutral, which is nice, but it hotspots at least as bad as the Sintra. Plus, there's a "shimmery" look in the hotspot that makes it even worse.

Gain wise, it's hard to say. Outside of the hotspot, it looks like the TS is brighter. I think I shouldn't trust my eyes though, as the color difference could be throwing off my perception. I will say that I don't think the DW is any brighter than the TS, and it seems to be a bit dimmer.

It does show though how big a difference a color neutral screen makes. If I didn't have a way to fully calibrate my PJ, I think I'd be hesitant to go with the TS. However, it's close enough that it'll be easy to calibrate. I'd rather a screen be deficient in blue than in red, as bulbs lose more red over time. Of course, color neutral is preferable, but with a full CMS I'm more concerned about wringing out every last ftL.

I thought the WA DW was supposed to be a good screen? Is it possible that it's changed? I mean, it's a really bad hotspot.
 

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Looking forward to the future comparisons Nak! :T

I will have to admit to being disappointed by that article at Projector Central since they did almost everything "by eye" without bothering to do any actual objective testing with instrumentation . I know that most people will say "hey, I don't watch my movies with a colorimeter or spectrophotometer beside me, it's what MY EYES see that is important to me!". While that is a true statement, the human eye makes a VERY poor colorimeter or light meter. The author said "... the Behr imparted a more obvious color imbalance, biased toward blue"; I find that quite interesting since NO sample of Behr white paint that I have ever gotten has ever pushed blue. It has always been extremely close to the Valspar Ultra Premium enamel white (so close they are interchangeable in a screen mix) and both whites have always measured "warm". It would have really helped for PC to have included at least CIELAB color data, if not a full spectral chart, to back their claims.

One more thing to clear up about that article. Speaking of the difference between their StuidoTek 100 and the ProClassic Smooth Enamel Satin Finish screen they said "A spot meter confirmed what we could already see--white highlights were brighter by about 10%, and blacks were blacker by about 10%". The reason why this could be is because the SW 'Extra White' color is NOT an "ultra white" paint, but is a very, very light gray; this would give deeper blacks over a bright white screen. The added whiteness (or rather brightness) would be due to the SW paint being a satin finish having more gloss than the matte StudioTek thus more on-axis gain.

And I still say they couldn't actually detect a +- 10% brightness change with the naked eye. ;)
When I first read PJC, I thought Evan knew what he was talking about. After a short time, I realized that his articles were pretty generic and his knowledge of the subject somewhat remedial. There are a handful of good and knowledgeable reviewers out there. Unfortunately they don't get the spotlight as much as PJC.
 

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Discussion Starter #19
I recieved my sample of Carada Brilliant White yesterday. :D I am VERY pleased with the comparison to Titanium Sintra. The BW is advertised as 1.4 gain, and has been tested here I believe at 1.3? At any rate, here's my initial observations.

TS is slightly closer to color neutral.
TS is very close to identical--if anything just a tiny bit brighter--at a direct viewing angle.
TS is CLEARLY brighter at off angle viewing. I didn't measure the angle, probably 45 to 50 degrees. As you increase the angle, TS becomes even brighter in comparison.
Blacks are indistinguishable between the two.

Again, I'll post graphs, data and pics later. It could be a while though as life is about to become very busy.

I'll still try and get another sample of WA DW, and I have one more paint sample to do. After that will come pics and graphs. For me though, I'm convinced. Titanium Sintra is precisely what I was looking for. I'll paint a new screen with it and do the comparison samples against the full screen. :D

Thanks to all for your help & advice! Maybe I can talk Mech into doing gain measurements? Whenever you have time?
 

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Maybe I can talk Mech into doing gain measurements? Whenever you have time?
Let me know. I'm at that time of year that I do all this kind of stuff. :T

Whatcha gonna call this diy screen? Gotta have a catchy name. :bigsmile: Also, what's the total cost?
 
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