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A Simple Screen Paint Solution - Page 3

post #61 of 143
I agree.. great example and a change of 5 doesn't seem to be as big of an effect with Red and Blue, but the Green really shows it... which goes back to what you said before Prof about a slight green deficency not being bad, but it really shows with even a slight push.
post #62 of 143
Here you go:

post #63 of 143
Thread Starter 
Prof55 Thanks for posting them.
If nothing else you are pointing out the difference to me between my LCD monitor at work and my CRT at home and lack of calibration on both.

But actually like a screen shot they are all seeing the same effects of my monitors at the same time and I think the blended gradients are a great way for us to get our hands around the feel of this. By that I mean I now have a ball park idea at least of the magnitude of change we are talking about.

For those out there reading and viewing these strips what they are is two distinct different colors slowly transitioning across the strip. The color on the left is a true representation of a neutral gray and the color it changes to on the right is the measured values of lampblack mixed with UPW per my post number 61. I'm referring to the 3 strips prof55 posted in post 65. The neutral value on the left I came up with by averaging the 3 numbers in the RGB value we got by actual testing a sample.

Anyone viewing these keep in mind the color you see is only as good as the monitor you are using and its calibration.

My screen is actually very close to the 211 207 221 LB gray in the top strip and looks pretty close to what I see in the left hand side of the top strip.
See thumbnails below





The big question is this. How far apart are the two ends of the strips in terms of real world PQ?

I went into my settings on my projector the other day after the project to black ok very dark gray experiment to make sure everything was back to where it was and I noticed I was at color temp 7500 deg not 6500 that I thought I was at. Sometime on my projector when you change between canned cycles such a s movie or game etc the color temp changes back and forth. I was almost always in custom and in that set at 6500 I thought.
I changed it back to 6500 and didn't like the image at all I tried several DVD's that I know have very lifelike skin tones to my eyes and 7500 was what I wanted it to be.

I believe these type adjustments on the projector are much greater changes than what I'm seeing across these slides.
post #64 of 143
Thread Starter 
Tiddler

I think what you are trying is very interesting and it's the right approach to take. If you look at the point on the color wheel the combined RGB of any sample is and then look at the point 180 from it most likely that's what has to be added to draw the color to neutral.

You and I have had the talk before as to what color all the different whites really are and UPW has become the kind of hallmark white around here and as we see
UPW is 253 244 253 from testing. So within itself there is a 9 point spread. Other whites I'm sure will change also.

It would be nice if prof55 could submit some of the whites we talk about a lot to testing just to get a feel of that also. Kilz primer is one that would be interesting to see. I used American Traditions version of a UPW base.

I know there is a great desire among some of us that think about this a lot to nail a perfect RGB mix and to be honest the gallon of paint is going to cost the same if we find a drop of this or that is what's needed. The closer we make the baseline the more unplanned variability wont change the outcome a significant amount.

My goal as to neutral grays hasn't changed although my understanding of them has somewhat. I still hope to get to a point that everything I outlined in post one can happen for people seeking a simple paint mix with the added performance a gray adds. Within the limits of their projectors. The basics of the beginnings of this thread you have reiterated over the last few weeks. The first being the benefits of extremely low gray levels in an otherwise white screen. And two the benefits of slight poly enhanced top coats.
post #65 of 143
Thread Starter 
Thinking about colors here.

Another member has posted a few screen shots on another thread to a screen that measures in the good neutral gray range and his mix was

Sherwin Williams Gray Screen SW7071
BAC Colorant 02 32 64 128
B1-Black - 20 1 -
Y3-Deep Gold - 5 - 1

RGB is 199 203 203

I see numbers around 20/48 a lot in the LB part and it was interesting (deep gold) was the balancing act in this one. Gold / Yellow Oxid. Both are close on the family tree I would guess.

And this gave thought to something. We all know that in the end it will be imposable to make a paint mix plan that has no variability to it. We have many white bases to start with and all the pigments have some variability in both content and mix rates. We are pretty sure LB alone will make a fair neutral gray but we also know without trying to hard we can do better.

Here is my thought. If we get a color push in some direction and we don't have a handle on what direction we end up with something lacking in color balance. If it is a blue push where would we see it? Our eyes work by comparison to known samples we keep in our brain. So now I have a blue push and I watch a movie of sky or water or trees the blue slight blue might even add to making the image look better to our brains and at worst it would just look like it belonged. If the push was red fire might look better and faces would look a little more red but that's naturally correct color to add to skin tones yellow also.

I'm proposing we try and reach neutral gray and then if anything we error on the side of skin tones. That's the one thing I always hear about paints with strong blue pushes the skin tones look muddy. With all the reading I have done here I have never heard the ocean had a strong blue push or the trees had a strong green push. I think content plays a role in this somewhat. I think PB_Maxx has tried to point this out a few times also. And the advanced mixes seem to get a pinch of gold if I remember right.
post #66 of 143
Quote:
Originally Posted by bud16415 View Post

Thinking about colors here.

And the advanced mixes seem to get a pinch of gold if I remember right.

A "pinch" to grow an "inch".

That is all.
post #67 of 143
Quote:
Originally Posted by bud16415 View Post

When raw umber was the corrective agent of choice I couldn't detect any difference with it in the mix or replaced with LB. Now that it may become yellow oxide I guess I'll have to try it and see.

Although I have no experience with yellow oxide, I have worked with lamp black, black paint, silver metallics and raw umber. What I found was the higher the concentration of LB, silver metallic, black paint or mixtures thereof, the greater the blue push. That is, given a high enough concentration, the blue push became obviously visible. Likewise, the addition of raw umber offset this blue push. However, I did (not) test to see what corresonding proportions of raw umber were needed to best offset any given blue push and to avoid any other adverse effect.

That said, it's good to see the effort has continued for a better simple paint solution. One thing is for sure... these newer solutions are defintely more neutral and thus better than "misty evening" (ME). Progress has been made.
post #68 of 143
Thread Starter 
Prof55
In the last 3 strips you posted, that represent the LB grays.(post 65) There is a 10 point shift between R&B where R is the lower of the two, and in both cases G falls lower than the R by about 4.

When comparing these by eye to the earlier strips you provided (post 62) at least to my eyes the 10 point shift off of the mean true neutral gray is far less noticeable.

This could be a couple things. It could be the lower green having some ability to change how I'm seeing the shift, or it could be when I averaged the 3 RGB numbers when I asked if you could post them in doing so I gave you a lower neutral gray value for the comparison to be made to.

Any thoughts on this anyone? Is it the math or the color?

1Time
Thanks for the input. What you posted was pretty much what I have been reading from day one here as to what raw umber adds. Who knows it could be a blend of gold, yellow, and umber that pulls things right on center neutral.

Like you I don't have any tool to measure where I'm at other than my eyes. The truth lies in someone with an analyzing machine willing to by trial and error or computer modeling home in on the balance of center neutral.
post #69 of 143
Quote:
Originally Posted by bud16415 View Post

Prof55
In the last 3 strips you posted, that represent the LB grays.(post 65) There is a 10 point shift between R&B where R is the lower of the two, and in both cases G falls lower than the R by about 4.

When comparing these by eye to the earlier strips you provided (post 62) at least to my eyes the 10 point shift off of the mean true neutral gray is far less noticeable.

This could be a couple things. It could be the lower green having some ability to change how I'm seeing the shift, or it could be when I averaged the 3 RGB numbers when I asked if you could post them in doing so I gave you a lower neutral gray value for the comparison to be made to.

Any thoughts on this anyone? Is it the math or the color?

I think the reason we perceive less difference in the last set of strips is due to our mind's ability to do its own "calibration". A push in a single direction is easily seen and identified, but an overall imbalance is less evident.

For example, if you set your monitor or projector to 5000K, it will look very yellow - at first. But over time, your mind will "auto white balance", and it will appear fairly correct.

The problem lies in the fact that when screen and projector are mismatched in any way, we suffer a major hit in performance. A single push is again obvious, but an overall imbalance gives us an acceptable but dull image. When everything is in sync, performance is drastically improved - and that's the goal!

Garry
post #70 of 143
Thread Starter 
Tiddler noted in an above post that he was finding some yellows (yellow oxid.) mixed in roughly a 4:1 or 3:1 ratio with lamp black were correcting the gray to what to his eye compared favorably with neutral gray samples. He then put this to the test painting out his home screen and then final top coat of Behr flat clear poly. By all reports and looking at his screen shots it looks like a very good neutral mix.

On another thread Wbassett used an over the counter paint mentioned above. He had done actual RGB tests to the paint and found it to be extremely neutral and he also put it into practice with excellent results. His paint is:

Sherwin Williams Gray Screen SW7071
BAC Colorant 02 32 64 128
B1-Black - 20 1 -
Y3-Deep Gold - 5 - 1
RGB is 199 203 203

This paint looking at this as a reverse engineering process yields the closest to neutral to date that has actually been tested I believe.

Can we now assume using a Sherwin Williams white base and a ratio of 4:1 Blackeep Gold we will get a close to neutral gray each time?

I also don't understand the (BAC Colorant 02 32 64 128) measurement scale. When he posted 20 and 5 are they in 48th of a oz or 32nd ?

Ether way the proportion rate is the same?

Can someone suggest a way to test a variety of samples in the 4:1 ratio? And also the number of points along the neutral gray scale that would be a likely area that many projectors would fall into?

What I'm looking for is how many shades? And a starting and finish mark along the grays?

I originally asked this same question of the people with vast experience here a year ago. Someplace on the first page of this thread. All the answers were basically off topic at that time. Much knowledge on my part has been gained between now and then but it was interesting reading back thru those posts again. Hopefully we will be able to put together the neutral gray scale / top coat scale that someone could find their projector on and go buy the paint they need and be done. That is if their projector falls into the range that these paints can help.
post #71 of 143
Thread Starter 
As of late I am coming more to the belief that the slight tweaking required of any lamp black mixed into a white base to obtain a close to true neutral gray is dependant on what white base and what manufacture that white base comes from.

I base this around reading all the threads of late involving finding and painting screens with neutral grays.

And in part I base this around a conversation I had at the paint store the other night with this guy that has been mixing paint for 20 plus years. I'm in the process of repainting the living room and dining room and went and selected paint chips for the new colors. The chips were from different manufactures and I prefer painting with one brand I have used a lot and grown to trust. So I ask the guy can you mix all these out of base from brand X. he said sure no problem all the tints come from the same machine and the color coding is the same, BUT he said I cant guarantee the paint will match that card 100%. He went on to say he would bet that it wouldn't match but using the correct base it would. I said is brand Y a better paint and he said nope both are good it's just that the base effects the color slightly. He even pointed out he wasn't talking about sheen as the chips are all a pretty low luster. He did say 99% of the people that come in the color would be close enough.

So what does this have to do with neutral gray screen paint? It's becoming apparent that lamp black and white when tested has a slight push to blue. Even though the screen I'm using is just that. It's common belief now that performance can be improved thru tweaking the push out and its been demonstrated thru testing that small amounts of pigment can be added and R=G=B numbers can be found.

Wbasset thread looking for off the shelf neutral grays and also some that Tiddler has identified and going way back to the very first neutral gray threads tweaks have been suggested.

The pigments that keep coming up are Yellow Oxid, Deep gold, and Raw Umber, etc. They all fall on the opposite side of the color wheel from offending push and dependent on what brand of paint and how close to R=G=B you hope to get the ratios seem to be 1 part correction pigment to 4 parts lampblack. (In that neighborhood)

I'm at this point only reporting what I have learned and until such time I get a spectroscope (not likely) or I figure out another way to determine RGB gray neutral paints. I'm way beyond what my eyes or anyone else can see as neutral.

It's been 8 days from my last post without input so, I'm assuming the major thrust and interest in a recipe you could walk into a paint store based around your projector, your room and your screen size and walk out with a gallon of easily to roll paint all in one can, has about run it's course.

There is a lot of good information for a newbie in this thread and I would suggest it as a good first read for anyone. But please start at the beginning (post 1) as I have tried to update that post from time to time.
post #72 of 143
Thread Starter 
Todd
Your assessments are all very true I believe.

And if I had to list the steps to follow they would be these.

Pick some white base paint as a starting point. You mentioned Behr UPW #1050 and that's a fine starting place I would think. As long as its widely available throughout the areas that most members are located.

Find a tinting combination of two tints if possible lamp black and tint X and a ratio of the 3 that produces a neutral.

Test the neutral at the high and the low end of the darkness scale and confirm that it remains neutral.

Subdivide the range into some number of steps and assign a mix to each.

Find a way to make a recommendation of what mix works with what projector based on controlling factors.

Then when that step is done or at the same time follow the same steps pertaining to the addition or the use of poly. And once again maybe one poly should be selected to have some control over the consistence of outcome.

This is pretty much the plan I laid out back in March 2006. With the addition now of correction to the lampblack only mix I used. I still have no idea why LB only worked in my case could be the American Traditions white base or it could be my projector, but I'm actually viewing at 7500 color temp. I know of two others with the exact same projector that used the same mix and both of them never got a blue push also.
I used Olympic clear matte poly in my mix.

The wbassett found color was a Sherwin Williams Gray Screen SW7071 that came in pretty neutral but I'm sure that was made with a SW white base.
What is the closest UPW based neutral that we have actually seen test numbers on?

As for the black test I will try it out. I have the flat black stage paint already so a quart of Behr flat poly is all I need.

I have had similar experiences with putting clear over a color. I once painted a set of rims with this spray paint that was supposed to look like chrome. It turned out awful and I was about to take it off and try something else when I tried spraying some clear over. It went from ugly to the most beautiful satin chrome look I ever saw.
post #73 of 143
Thread Starter 
Opening post edit
post #74 of 143
Thread Starter 
I posted into a different thread about getting a Munsell color reference book and having the color cards scanned in with a good quality paint store scanner, one that actually formulates the pigment around a certain brand of base. I thought I could have this done for several different Munsell's and then in several different brands of paints. This would be an attempt to find both the correcting pigment but also a way of seeing the variability in the white bases of different manufactures.

If I cant get my hands on the Munsell charts my second thought would be to get some paint chip cards for some of the close to neutrals such as Sherwin Williams Gray Screen SW7071 and have the cross reference done. If anyone has access to the Munsell reference charts or has a willing paint store mixologist please feel free to gather any information and post back.

Even if we had Sherwin Williams Gray Screen read in and reformulated say into a Behr base it could tell us a lot. I think.

Too bad a mixing program wont take a RGB number and spit out a paint mix..
post #75 of 143
Dumb question, but why are you trying to reformulate Sherwin Williams Greyscreen into a Behr base?
Why not just use the Sherwin Williams Greyscreen w/o the fiddling since it seems to come the closest? Or do a quick coat of clear poly satin over it and be done w/ it? Most people would probably be happier w/ the minimal amount of work...and Sherwin Williams is a better paint than Behr anyways ;-)
post #76 of 143
Just an FYI, you have to get the matte finish by the gallon, if you want it in a flat finish you can still get that by the quart for around $12 (I just called to confirm that), so it's not really any more expensive than getting a flat version done with UPW.

I understand what is being done and it's a great idea, but we'll need to get it tested since it's going to be made with a different base and color pigments. I'm not arguing or disagreeing, just saying it's not really that expensive unless you specifically get the matte finish. (which is a very nice finish BTW) Plus there are 10 stores listed within 25 miles from me as compared to 6 for HD, so in my case there are actually more SW locations. I'd say use the store locator for either place you want to go to find the closest store.

Bud same as what you said in the gray thread, I'm not trying to hijack anything, just maybe clarify a couple items.

Pretty much it's back to a preference thing. If you want it in a flat, then there is no price difference between Behr and SW, so if it were me and there was a local SW I would just go there. If someone wants the matte finish then it's a bump up only because you have to get it in a gallon, but I am sending out some of what I have left to some people... so you can defer the cost right back down to the same if there is someone close that wants to try it and split the cost.

kenyee I don't think they are trying to create the same color, more like figure it out so some intermediate colors can be made. Bud you can correct me if I am wrong on that...
post #77 of 143
Thread Starter 
Sometimes I think kenyee is right I think most people haven't seen the slight change in a shade of gray and the PQ improvements it can make.

When you think about it a paint like (silver screen) by all accounts a pretty bad representation of a neutral gray and it was widely used and liked by a lot of people.

Goo offers just a couple shades and nothing in the way of doctoring the topcoat. And they are a successful company selling it by the barrels.

Only one or two of any homemade DIY advanced mixes have more than one mix.

So we could just say here it is world, you can shoot to killz2 primer or Sherwin Williams Greyscreen. And be done with it. Maybe 99% of the world would go thanks and go paint one and enjoy. We should stipulate under 1000 lumens use killz2 and over 1000 lumens use Sherwin Williams Greyscreen.

That would be the short answer to this and I'm assuming kenyee was asking a serious question. But as Tiddler pointed out, we think there is valued improvement in a breakdown of less than two. This situation is coming up in a thread I have been following dealing with the counter top laminates being used as a screen. Some of the reports are coming in with glowing results using the gray material and then some are seeing problems. How can that be, well there are about a 100 different projectors being used and 20 different screen sizes, add to that different placement of the projectors and varied ambient light levels and the combination of conditions for viewing are astronomical.

What we are trying to do or at least what I think would be nice is to give a person coming here the benefit of the collective knowledge here in a format they can use to quickly select a DIY application. And not just a ok application but a correct fit.

When you buy shoes there are about 20 size combinations to pick from. Would we be happy if when we went in they said we have size 10's only. If you have small feet wear more socks if you have big feet they will stretch.

When you go to subway for a sandwich. We have white rolls, meat balls and coke that's it.

Even Volkswagen couldn't keep going building just the one type bug.

Well enough of my ramblings I couldn't get many interested in a tailored approach to screen painting 9 months ago and I still see pretty limited interest at this point. The approach has been used by many and that is in itself a good thing.
post #78 of 143
Don't give up on that spreadsheet Bud, it is an outstanding idea. Kick it up again and I think it may take root this time. Look at the laminate thread, that isn't a new material, it was used before and got buried in the archives. This time around it took off.

We do have several Munsell shades available, but not a very wide variety. I looked and I really couldn't find anything that matched the step colors. Well I did, but it was a totally different paint company and I don't think it's a good idea to start mixing and matching different manufacturers with different base components etc...

kenyee this is what I think Bud is trying to do, find a way to fill the void for the intermediate step colors. That's not reinventing the wheel at all, it's improving on it.
post #79 of 143
Very interesting info tiddler!
post #80 of 143
Thread Starter 
Todd

So if understand this correctly the parent company has a paint color number that is universal. They do this because they know all the satellite paint companies may or may not have the same bases or even pigments to mix the color from. What they do is a conversion from these numbers based around what they are trying to make and I could be in Asia and get the same color as if in Canada. The paint may be made from different stuff but the color will be correct.

It seems these numbers give a location on a color chart much like a RGB would and then combine that with reflectance and intensity.

Did they give you some indication that mono gray is another name for neutral gray or munsell gray.

It is interesting how the colors black , yellow oxide and red oxide keep popping up and in about the same proportions.

On a slightly different note I have long been puzzled by why my projector on a lampblack only gray shows no blue push nor do any of the other XR10 users that have made my same screen. Even though I'm running at 7500k color temp. well there has been some discussion about the 10X's actual color temps and some testing has been done and its been found that the 10X along with most projectors are not 100% truthful in having a actual reading correspond with what things are set at. Seems most projectors lean in the direction of whiter whites and that involves blue whites. All these specs are like shell games including lumens and none of this makes matters easier because they don't all tilt things the same way.
Just like our belief that along with none of the white bases being white actually are also not true to each other.

So in my case it was actually desirable to possibly have a slight blue push, seeing as how that push kept me in the center of almost all my calibration adjustments. The end result is a great image.

Up and until this point I had a gut feeling projectors had variability but had hoped that those variability's would be contained to lumens or mostly lumens.

This could go back to Wbassett's observation of the slight vee curve to almost all commercial screens and to my thoughts that gray error should fall in a predertimed direction and maybe even over shoot neutral on purpose. If you remember me saying what colors do our minds compare whenever we see a projected image. Its always the warm skin tones.

I remember my mother yelling at my dad circa 1965 as he was down on all 4's with a little screw driver turning little knurled posts in the back of the Magnavox. She would say Wait till they get a close up of a face. That was always the standard to adjust to.
PB has always commented on flesh tones also in screen shots. I guess all the other things we see in an image can be off a little and we don't see it like we do black, white and skin tones.

I think at this point anyone that wants to make a study of this like a few of us here have has the knowledge to know what needs to be done and how to tweak to a final result. The question is, how do you convey that thought process to someone and eliminate all the trial and error steps and still label it simple?
post #81 of 143
Bud an interesting thing I noticed with the 'V' curve is that as the color gets darker the green deficiency decreases(starts moving back toward neutral). The red and blue values pretty much fluctuate the same, but never exceeding a 5 point push or deficiency. It appears they are tweaking the screen to be warmer or cooler temperature but basically keeping it close to a neutral midpoint. Pushes/deficiencies with red and blue beyond a temperature setting for the screen to me is for:

1 To aid with some minor incandescent lighting and
2 A slight blue push beyond temperature control could be to aid in brighter perceived whites.

Green is the big variable and like I said it goes from a 9 point deficiency to a 5 point deficiency as colors get darker and depending on the manufacturer. This kinda supports what I was thinking/saying that the color variance of the screen isn't as critical with lighter colors, but going darker needs to be more balanced, or at least closer to that neutral midpoint level.

Here is what Gary said when I was originally questioning the 'V' curve and the desire for neutral colors--
Quote:


I think the commercial screen green deficiency is due to several factors:

1. Too much green makes skin tones look bad; too little is not very noticable.
2. Titanium dioxide/lampblack/raw umber are inexpensive, nontoxic pigments.
3. Effective green pigments are expensive and toxic (cadmium, etc.)
4. A truly neutral screen is ugly when the lights are on.
5. True neutral is only a small advantage - meaningful to us, but probably not to them.
6. A true neutral color would require extremely close manufacturing tolerances.
7. We are the only ones who are crazy enough to care.

Mere speculation on my part, but I believe these factors are enough to prevent the big guys from producing a neutral screen. It is most certainly possible to create one - it's just not that advantageous for the big companies.

Garry

So neutrals aren't a bad thing, just harder to achieve and getting to that 98-99% performance which is typically only 1-2% beyond most really good commercial and DIY applications. If I understand Gary right it's more to do with cheap and easy to get the best performance/profit ratio.

Now based on that, neutrals will work, and we know the 'V' curve will work very well too... so in my opinion I would use the Munsell levels as the neutral midpoints and work the V from there... slightly larger green deficiency with an N9 shade and decrease the green deficiency as the shades go darker.

I do have some ideas and created some color swatches based on some 'V' curves I worked out, but I want to do further testing and research on that before getting into them on any threads in here.

It sounds like Tiddler has already found some excellent information for this thread to sink its teeth into.
post #82 of 143
It seems we keep leaning towards Home Depot options which is great for me (I have one just 2 miles from my home). So I emailed Glidden and summarized what the last 3 pages have basically stated. I assume they must have some "color engineers" who would readily have access to RGB numbers. Even if they do not generally deal in RGB , they could surely convert to these values somewhat easily.

My setup is a Mitsu HD1000U in medium ambient light shooting a 90" screen, often with two 60 watt ambient lights approx 12 feet from the screen in back of the room. Of course they are off for cinema, but lots of HDTV sports will be watched also. I am willing to compromise some ultimate performance in the dark for a decent picture during the day with my so-so ambient light control. I am looking for an N7.5-N8 value- perhaps a bit darker than most may be considering as a result. Hopefully I will get the name of someone who answers and we will be able to continue to harass this poor soul... ;-)

My request to the Glidden technical people was a baseline neutral gray 185 185 185 to 195 195 195 as that is the shade I desire and I then detailed that a mix like 189 185 190 is ideal - "Classic V" with a slight red drop relative to Blue for my incandescent lighting.

I can't help but think they must have some sophisticated modeling programs that they could give us a custom spec to give to the HD counter, even if there is no specific name for the color. How about PiotroProjecto? That ought to sell at least 2-3 quarts with a name like that. ;-)

The auto reply from Glidden says I'll get a reply by Monday 12/18. LOL. I'll advise what I hear.

P.S. I don't want to mess up the simplicity of this thread but my ultimate goal after finding the right gray is a "fancy topcoat" Maybe 5% SM in Poly or 5% SM in Faux glaze- still have not figured out the difference between the Faux glaze "depth" vs the poly "depth" as they seem to be extremely similar in function. Or even one of the two with some tint of the magic Glidden color the experts are feverishly working on for me now! (I can dream can't I?) I will likely shoot both with an HVLP.
post #83 of 143
I actually like Glidden Evermore paint a lot....it covers very evenly (Behr IMHO is very blotchy, but some people swear by it). Benjamin Moore and Sherwin Williams are even better than Glidden in terms of smooth coverage.

Yes, my question was serious. It just sounded like Bud was going through hoops trying to get Behr to match what is a close to ideal for this application Sherwin Williams color. I do appreciate all the work though ;-)

FYI, the "standard" for color matching is Pantone colors. If any of you guys has access to a graphics department, they can look up the official name for the baseline neutral gray or the classic V color. Glidden no doubt matches all their colors to the Pantone set, I'd bet. Anyone who does printing/graphics applications does...

Looking forward to mpiotro's Glidden reply. Since it's in all countries, it sounds like a good choice for everyone to standardize on... :-)
post #84 of 143
Thread Starter 
Mpiotro welcome to the discussion and AVS. Your comments are very interesting and we all await any information you can bring to this topic.

Kenyee welcome back as well and also some good input.

Wbassett as always some thought provoking reads.

Tiddler I'm reading thru your latest offerings again and if we can get some of these tested I think we'll have some good base points.
Your point is well taken that once we do find a path be it in some base white starting point. We have to find a way to distill this information down for the average Joe

Wbassett mentioned the other day that maybe we should take another run at the spreadsheet program. For those that are new here. Member Movielvr2006 and myself had at one point started to devise a type of calculator/ spreadsheet that would let average Joe enter a bunch of fields and answer a list of questions. And the program would provide him with a neutral gray paint mixture for his specific application. Most of the work was done by Movielvr2006 and we put the project on the back burner because we didn't feel we had enough data points to do a good job of it at that time. I know that's a way off still but I want to stay in the sprit of the original concept of this thread. Even though the target of what is neutral may have moved from my original starting point somewhat. I want the end outcome of this (if possible) to be a visit the forum and find a set of directions that lead you thru some logical process. Armed with the directions you go to a paint store and buy one item mixed by them as simple as if it were a named paint.

That should be step one step two should be just as easy if needed and that would be to apply a topcoat to it if for no other reason than to protect the surface. But hopefully to give an added PQ improvement.

Everyone is aware there are advancements beyond these screens but I think all the work Todd has been doing this is where the simple line has to be drawn.

And lastly don't let me get in the way of anyone's ideas or input here as far as I'm concerned there is no off topic as long as the end result is simple in concept and in the ability (skills) required to put it into use. And it's a neutral gray that can be customized by need.
post #85 of 143
I'll add this, my first screen as a guess from the silver screen. Project Optoma HD72 in a light controlled room.

Behr UPW #1050 base, flat.
LB 0 12 0
UMBER 0 4 0

Testing using a calibration meter (spyder 2 and hcfr) has revealed a heavy blue push. So much that blue must be decresed to -12.
Also on the CIE charts the greens and reds are over saturated, meaning too much. Plus the gamma curve is way off at 90% severly spiked at 90%, but generally to high for the entire profile.

My thoughts, test a forumla such as:
LB 0 22 0
Yelow Oxide 0 5 0
Umber 0 5 0

Any ideas or suggestions as to the above mixtures/ratios???
Where can I find the RGB for SS?
post #86 of 143
Thread Starter 
Quote:
Originally Posted by bean-66 View Post

I'll add this, my first screen as a guess from the silver screen. Project Optoma HD72 in a light controlled room.

Behr UPW #1050 base, flat.
LB 0 12 0
UMBER 0 4 0

Testing using a calibration meter (spyder 2 and hcfr) has revealed a heavy blue push. So much that blue must be decresed to -12.
Also on the CIE charts the greens and reds are over saturated, meaning too much. Plus the gamma curve is way off at 90% severly spiked at 90%, but generally to high for the entire profile.

My thoughts, test a forumla such as:
LB 0 22 0
Yelow Oxide 0 5 0
Umber 0 5 0

Any ideas or suggestions as to the above mixtures/ratios???
Where can I find the RGB for SS?

Good info bean-66

The RGB for silver screen is 207 202 215 as posted in the wbassett thread

http://www.avsforum.com/avs-vb/showthread.php?t=704900

SS mix rates are black 0 20 0 raw umber 0 20 0 and X red 0 2 0 per gallon

Tiddler has had some success with the LB and yellow oxide mixed in the 4 parts LB to 1 part YO. But I don't know if those samples have been checked out on a spectroscope yet.

As a point of interest pure UPW has been measured at RGB 253 244 253 and LB at 47 45 49. It's my contention that the small percent LB that is used and its relatively low RGB number work together to not reflect much light and something that doesn't reflect much light plays a small part in changing the reflected color.

SS used a high good amount of raw umber in the mix and by many accounts had an awful blue push and its RGB numbers seem to prove that out.

Lamp black only grays made in UPW measured thus.
5/48 LB/qt = RGB 211 207 221
11/48 LB/qt= RGB 201 198 213

Both have the Vee curve and also the high blue point.


Bean-66 : It would be interesting to see the mix you suggest tested. But what gave you the idea to try a umber / yellow combo?
post #87 of 143
Thread Starter 
Quote:
Originally Posted by tiddler View Post

I also ran across prof55's readings for Da-Lite High Contrast Matte White, 208/203/209. My (3:1) LB + YO samples look remarkably similar to the HCMW sample I have.

I don't know what to make of it ether. Some paints exhibit this green deficient slightly tipped Vee curve and are excellent commercial screens and or excellent DIY screens while others with a very similar Vee but slightly more pronounced suffer the blue death.

I wouldn't have guessed the last poster bean-66 would have seen what he reported with that moderate LB , umber mix.

Anyone have any ideas???? Do things like sheen, gain and texture play any roll in this????
post #88 of 143
taking a look at try'gs thread... it becomes clear what happened in bean-66's case. not all stores use a lamp black that is entirely black. in fact, the lamp black found at many retail outlets has a deep blue tint to it... hence the recommendation of umber to bombadil grey to make it more nuetral.

bean-66's case was probably a worse case scenerio.

the oversaturation of green and red also makes sense... and it can be attributed to the umber that was used.
post #89 of 143
Thread Starter 
Quote:
Originally Posted by pb_maxxx View Post

taking a look at try'gs thread... it becomes clear what happened in bean-66's case. not all stores use a lamp black that is entirely black. in fact, the lamp black found at many retail outlets has a deep blue tint to it... hence the recommendation of umber to bombadil grey to make it more nuetral.

bean-66's case was probably a worse case scenerio.

the oversaturation of green and red also makes sense... and it can be attributed to the umber that was used.

PB
What one of Trygs threads should we look at? Can you tell us what retail outlets of paint use blue biased lampblack? Is it a certain store or brand of paint that we should stay clear of? This is the first I have heard of a variability problem in lampblack. Has this been widely known for some time? I was placed under the misassumption that there was some standard governing pigments. Even thought its widely known there is variability from brand to brand given the same formula. I assumed we would be fairly close. The drastic difference we are talking about here is all the more reason to work within on manufactures brand. And even then it may be imposable if the variability takes place at a store level.

Bean66
Can you tell us where you bought your paint so someone can look into this blue lampblack issue?
post #90 of 143
Bud:
I purchased this from my Local HD store.

I came up with the mix based upon what the paint person told me about the mix of the Behr silver Screen. And I not wanting to add a lot of other stuff to the mix decided to only add the umber in a smaller amount.

I came up with the idea of adding yellow based upon the prior posts regarding SS rgb leves, reading that adding yellow to the mix should conteract the blue push and my own experience during measuring that there is indeed too much blue being reflected. This is pretty obvious during displays of dark images.


PB.. I'm not sure about the color pigments for the LB. All I can really say is this particular combination produced a significant blue push and also an oversaturation on the green and red. Blue was a bit undersaturated after I performed calibration using the spyder. The net result of each calibration (multiple attempts due to the learning curve) was that the blue gain (contrast) had to be reduced at least 10 to 15 units (whatever those are on the optoma hd72) below the other colors in order to get even close to a 65k color temp.
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