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A Simple Screen Paint Solution - Page 2

post #31 of 143
Quote:
Originally Posted by jilebi View Post

Hi Bud,



Am I missing something ?

Thanks.

Most likely Bud himself unless he changes gears and decides to post again.

Poly is a "Clear or "Clear Satin". No one has ever advocated Poly in Clear Gloss form.

Paints that exceed the sheen in Eggshell also jave never ne used with any results except Hot spotting.

Even Eggshell has specific limitations, but can effectually help a Lower lumen PJ's gain.

What's happening with Bud's 50-50 ratio is a considerable thinning of the pigmented paint, something none of the aforementioned varieties in your post adhere to.
post #32 of 143
Hi MississippiMan,

Thanks for the prompt reply. A couple of things

1. What is the difference between Poly Satin and Poly-Gloss ? Aren't both of them 'clear' ? i.e Woulden't poly gloss in lesser proportion ( say paintoly gloss of 70:30 or 80:20) be equivalent to poly satin ?

2. So the reason eggshell base for white would not work is that while providing the gain at the top coat, the pigment is not getting thinned out. Why is thinning important ?

Please forgive if the questions above sound naive. I am indeed very ignorant about both paints and screens ! But I am willing to learn.

Thanks.


Quote:
Originally Posted by MississippiMan View Post

Most likely Bud himself unless he changes gears and decides to post again.

Poly is a "Clear or "Clear Satin". No one has ever advocated Poly in Clear Gloss form.

Paints that exceed the sheen in Eggshell also jave never ne used with any results except Hot spotting.

Even Eggshell has specific limitations, but can effectually help a Lower lumen PJ's gain.

What's happening with Bud's 50-50 ratio is a considerable thinning of the pigmented paint, something none of the aforementioned varieties in your post adhere to.
post #33 of 143
jilebi,

i also did something similar to Bud but my poly to latex ratio was smaller (25% poly, 75% neutral gray latex). my screen looks pretty good in my opinion.

about your idea to use other sheens of the latex, i have been kicking around that idea also. sure, the poly thins the pigments and makes the paint less opaque, but is it necessary?

in the spirit of this thread, what is being asked is there a simple solution and your idea would be just as simple as adding poly to latex so i think it is worthy of a try.

you could try an experiment that i've been thinking about. first, determine what shade of gray you think you need. the size of your screen and your projector output should tell you which shade. if you want, send me a Private Message and i will walk you through the same process i used in picking the shade. once you have your shade picked out, then buy 1 quart of the gray in "flat" and 1 quart in "eggshell". with both sheens in hand you can mix them in different proportions to get the desired affect that you want.

i don't think you are missing something, just asking an interesting question.

Quote:
Originally Posted by jilebi View Post

Hi Bud,

Great thread that you have started. What you have stated makes eminent sense to me, from the science perspective. Start with pure white, add black until the shade of gray just makes the whites a bit dull but adds to the blacks and then add poly until the gain matches what you need.

Here is my follow-up question on the above. When you started out out with the base white, why did you choose the the flat version instead of eggshell, satin,semi-gloss, gloss or any other sheen ? If eventually you are going to add poly to add to the 'gloss' for increasing gain, why not have that in the base white itself ? Would it not produce similar effect but in fact be cheaper by reducing the cost of poly ? In the mix cost, the base istelf costs only 10 bucks a quart, but the poly costs 15-16 bucks for a quart, which is quite expensive relatively. And if you need grades of poly, then the base white paint comes in five levels of sheen at Lowes ( flat, eggshell, satin, semi-gloss, gloss ). Surely one of them must be equivalent to levels of poly-satin ?

Am I missing something ?

Thanks.
post #34 of 143
Hi movielvr2006,

Thanks for the feedback. I would certainly like to do the experiment on base gray with sheen, to make a simpler mix. I will follow-up with you via PM.

Thanks.
post #35 of 143
I believe every brand of paint has their 'base.' You can usually find this base on the shelf advertised as their flattest white. Everything else comes by adding color or shine to this. For Behr I guess this is Ultra Pure White. But its not any more ultraer or whiter than anybody else's white

I just painted on some Behr Silverscreen. WHen I was buying I asked the lady what colors were in it, and she showed me that it had a squirt of red and of 'umber' which she characterized as brown. It was brown. I asked if she had some paint with just black and white and we both had a laugh at the thought of anyone painting any room in their house with such a color. SO the answer was no. Furthermore at McDepot's they want to push the button. I wasn't offered any kind of color matching as I had brought my Dalite HCCV sample with me

If you want to see hotspotting try watching a hockey game. That ice really can shine up the surface of your screen. I wont be using a 2nd coat of silverscreen as mine is satin and I obviously should have gone with the Flat. But I wanted some shine to add gain since the greyness would be toning down the reflectivity. Bad choice.

Tomorrow, if they are open, I'm going to Lowes and see if I can't talk my way into an intensity match against my HCCV, and hold the color.

I taped a line on the wall with my laser level and painted a ~100" 16:9. I bought some flat black and im going to somehow add another tape line and paint on a black border. So I gotta work quick before this tape is on too long and does not come off clean.



By the way, this is a screen for my son so I don't have to watch him. He will eventually have his way with my screen. I'm sure of it. When company comes over Ill whip out the 110" dalite HCCV DIY screen...
post #36 of 143
The Stock Behr Silverscreen in Satin is dry now and looks relatively good. Its hotspotting somethin fierce though. A coat of flat SS tomorrow should clean this up.
post #37 of 143
Ahhhh......, but new people often need guidance and direction to maintain the frevor they themselves have generated.

I know of few here who recommend anything based on a whim or chance of the Draw. In my own case, I can esposse about the virtue of a "one can" solution to he who needs to focus on such, while turning around and presenting something else for someone else becuase his criteria, budget, and abilities deserve consideration in overall view.

In DIY, sour grapes can always become sweet wine except in cases where the instructions or proceedures failed somewhere if the grower huses significant care & feeding.
post #38 of 143
Yeah MM it's those that flipflop on a whim or what I am calling 'flavor of the week' that can really confuse someone new on here.

After spending some time reading (usually a couple weeks) I think new people start weeding out the Earl Schieb's of the DIY world, but that flavor of the week still raises it's ugly head now and then.

Tiddler is trying to cover the basics which is along with the FAQs is a much needed asset to the forums.

You're right though, some people may just want a simple off the shelf one or two coat solution and be completely happy, while others want a more high end application... and other's may be hooked on the neutral gray idea. I guess in the end all that matters is what works for someone and makes them happy is then the best application for their needs.
post #39 of 143
Ok. What is a simple solution, not necessarily one-can but simple enough to apply with a roller on drywall.

I have read both of your post MMan, wbassett, as well as tidler, pbmaxx and many others for the last 3 months but have yet to find a mix that isn't too dark, too blue, or too flat/dull.
The last iteration which I thought was getting close was Lowes pure white (quart) with 2 units of lamp black mixed 1:1 w/ satin poly and 3 oz of water. My logic followed bud's and others that white with just a touch of black should make a neutral grey. However after reading prof's thread I can now see why I don't have enough adjustment in the panny 900 to overcome the blue push since this color is actually a shade of blue and not grey. (btw: room has rust walls and cream ceiling - no windows).


I guess what I and so many other's are looking for is where do we get the most bang for the buck? Surely we don't have to try every formula or iteration (I am up to 12 coats).
If Silverscreen is too dark and a white/lamp black mix is too blue and white is not dark enough what would you guys recommend for an alternative?
MMaxmud, black flame, Whispy grey, universal grey, SS/WOP/Poly, which is the formula of the month? Given all environments are different it would seem that the best place to start would be a neutral grey with additives to create "pop"and adjusting the pj to compensate for the deficiencies.
post #40 of 143
My experience with Silver Screen wasn't totally positive for me... other's love it, I just think there is too much blue push and color shift for my setup and tastes.

Tiddler is covering the basics, so he's the paint man to talk to for easy to intermediate paint solutions. MM and pbmaxx are the Rembrandt's in here and well... what they do takes practice and paitience. Some may be able to do it their very first time, some may not. But if you are interested in their techniques PM them, both are very approachable and helpful.

Bud and Prof, along with Tom have researched the neutral grays and are great sources in that topic. Plus if you have any questions about colors Prof and Ericglo can provide a wealth of information.

Ericglo and Clarence introduced me to Wilsonart, although laminates are not something new on the forums, I'm starting to test different colors out hoping to bring it back to the forefront as a viable option for some. Right now thanks to Clarence we already can see what the Designer White looks like...

There are many many others on the forums with incredible experience and knowledge... I did not mean to exclude anyone, but right now these are the most active people posting so they would probably reply quicker than someone that hasn't been on in quite awhile.

I'd say first assess what your skill levels are and that will determine a lot of what you want to try. Next would be your screen size and projector... for instance do you need a contrast boost, things like that. Last would be how much time and money do you want to put into it. At that point I'd PM one of the active people currently on the forums and get some more details and instructions more tailored to your particular setup.
post #41 of 143
Thread Starter 
Davedeal
I understand what you are saying and feel for what you are going thru with some of this.

Just thinking out loud here if you went with 2/48 LB per quart and I was at about 5.5/48 per quart and then we were about the same at the 1:1 poly mix.

I'm trying to get my hands around a large blue push from such a small amount of LB. I personally haven't seen the blue push but maybe something is different. The gray you used is really slight and about what I would think you would want with the 900.

What did the image look like with just the 2/48 gray without the poly? Or did you go straight at it with the top coat mix?

You bring up an interesting idea and I'm going to state it here now and maybe some of the light pros with testing equipment will post into the discussion.

The reason the sky is blue and deep water is blue is because? I'm thinking back to my school days here. All the light spectrum is absorbed up to the blue wavelength and that's what is reflected back is how I think it works. The deeper and clearer the water the darker and richer the blue. Everyone assumes the blue push is caused by the LB (But) could it be the poly. Possibly a prismatic effect with the light striking the screen at an angle.

Food for thought anyway.

I'll post more if something pops in my head. Maybe someone will want to comment on the poly affect.
post #42 of 143
Quote:
Originally Posted by bud16415 View Post

Davedeal

You bring up an interesting idea and I'm going to state it here now and maybe some of the light pros with testing equipment will post into the discussion.

The reason the sky is blue and deep water is blue is because? I'm thinking back to my school days here. All the light spectrum is absorbed up to the blue wavelength and that's what is reflected back is how I think it works. The deeper and clearer the water the darker and richer the blue. Everyone assumes the blue push is caused by the LB (But) could it be the poly. Possibly a prismatic effect with the light striking the screen at an angle.

Food for thought anyway.

I'll post more if something pops in my head. Maybe someone will want to comment on the poly affect.

Bud I know Prof could answer this one with ease... next time he's on I'm sure he will
post #43 of 143
WBasset - thanks for the feedback. I subscribe to the majority of active threads. I also applaud the efforts of those you mentioned, without them us noobs would be nowhere.

Tiddler- here is my log, hope this helps.
Room is 14x14 w/ rust colored walls and cream colored ceiling and white'ish carpet - I know not the best but it's all I have to work with. Pj is a panny900 3mos old mounted 6' off the floor and 11' from the screen surface. Seating is 13'. Screen size is 104" diag (51x90).

Project in order of completion:

(used 9x1/4" foam roller and fine/super fine sanding sponges for all applications)

Skim coat joint compound on new (painted) drywall to flatten and smooth.
2 coats kilz2
* kilz was too bright and muddy looking

next day added

2 coats UPW flat w/ 1:.5 poly mix
* color was good but blacks were too light - washed out w/ ambient light

next day added

2 coats UPW exterior gloss wet-sand before and between coats
2 coats SS flat (HD ignored my request and used deep base instead of UPW)
* blacks too dark - no shadow detail, colors too purple, also has same muddy look

5 days later added

3 coats SS/Delta pearl/Poly also w-sanded between (16oz/8oz/8oz)
* blacks still too dark, colors not quite as bad but human lips are still too purple, muddy look gone, contrast looks good, whites are acceptable

3 weeks later added

3 coats Lowes Am Trad white base matte (quart) with 2 units lamp black mixed w / 24oz poly w-sanded before and between.

* this seems to be the best so far blacks are just about right with blacks being black not grey and good shadow detail. Whites are good and bright but not washed out. Colors still need some work, seems to have a strong blue/green push. Human lips are still purple and north atlantic ocean scenes water is deep blue not greyish.


For comparison I have a syntax 37" LCD in the next room (prof calibrated) while not perfect it does offer a good representation what the intended image should be. Same feed distributed - I can view same image at the same time on both displays.
I also have 12" samples of Carada Brilliant Wht, Classic Wht, Gray, Dalite HCMW, Damat, HP.
and 12" samples of several laminate colors (Designer white, folkstone gray, ash grey, etc., I have also been in contact with three laminate mfgs to find there offerings in a "neutral" grey. will update ). I'm not trying to match any one of these but have tried to use them to get an idea of discrepancies etc.

It seems that I am getting real close with the white/LB/Poly mix, but not sure which direction (color) to go to offset the heavy blue push.
Should I be looking into the metallics (mmaxmud, BF, etc). It's my interpretation that these have more to do with reflectivity than color/contrast.

Bud- you bring up an interesting point with the poly.
post #44 of 143
For what it's worth....

I had a similar adventure as yours - with the same projector (AE900) on a white drywall.

I found happiness just this week with a 1:1:1 mix of SS/Poly/Delta Pearl + Silver Metallic. Haven't noticed purple lips yet - but I'll certainly look for it tonight.

The only thing I noticed is going from straight SS to this mix is my whites are too bright - a simple calibration should fix this though. I'll probably do this over the weekend.

(If anybody has a sample calibration for AE900 with this screen, I'm all ears!)
post #45 of 143
Quote:
Originally Posted by tiddler View Post

Have you calibrated your projector each time you changed the paint?
The SS mix should have been (1:1:1) SS + Poly + Pearl. That would have lightened the SS more and given better gain.

Is the screen a very light gray now?

Yes


Quote:


A mix like (1:1:1:1) flat white latex + Minwax Clear Satin Polycrylic + Pearl + Delta Silver Metallic would produce a surface that was light grey with good white performance. In these pics the left is a flat white latex and the left is a flat gray + poly + Pearl + Delta SM (1:1:1:1).

What color is the flat gray? Is it a custom mix or a prefab?


Quote:


This mix is still fairly easy to roll.

I was actually surprised at how well the Gray Mix compared to the flat white in the dark.

This looks like it may fit my setup for the time being

Quote:


The Panny 900 is suposed to be fairly well calibrated out of the box (if I remember the reviews correctly). You may want to reset the projector for each new screen.

Yes


Quote:


I would suggest you watch my thread and don't rush out and try something right away.

Unfortunately I doubt It have that much patience - besides I am on a "roll"
post #46 of 143
Quote:
Originally Posted by tiddler View Post

It is Glidden "Wispy Gray". It was mixed in a flat white primer for my demonstration samples.

WISPY GREY FORMULA

CIL == Glidden
CIL DULUX Int. Latex -Flat
WISPY GREY (50GY 62/029)
Pure White (2110)
Per GALLON
B 0 22 0 Lamp Black
C 0 08 0 Yellow Oxide
D 0 02 0 Thalo Green

Thanks! I will post my results.
post #47 of 143
Thread Starter 
Quote:
Originally Posted by davedeal View Post

Thanks! I will post my results.


Dave
How did this ever work out for you?
post #48 of 143
Quote:
Originally Posted by bud16415 View Post

Dave
How did this ever work out for you?


Sorry Bud but I abandoned the paint and started investigating the laminate (DW) solutions.
Currently I have a sheet of Designer White tacked on the wall for evaluation.


DD
post #49 of 143
If there's one thing I've learned from you esteemed posters, it's that PQ is pretty subjective. I know for a fact that none of the screenshots you guys are posting are accurate to the naked eye view, so those are entirely a write-off too.

I got my 4805 in July 2004. Based on the comments here, I switched plans from building my own DIY screen to just painting one on the wall. I went to HD, got a can of Behr silver screen, taped off my bluescreen image, and painted two coats.

The results have been nothing short of astounding. I like my PQ. I can watch TV in the middle of the day with the shade pulled, and at night, with a single 60W bulb, the ambient light is just right and my PQ doesn't suffer. In darkness, DVD viewing is simply nothing short of phenomenal.

So thanks for the SS idea, guys! Keep the hardcore analysis going!
post #50 of 143
Thread Starter 
Edit to opening post.
post #51 of 143
Quote:
Originally Posted by tiddler View Post

It is Glidden "Wispy Gray". It was mixed in a flat white primer for my demonstration samples.

WISPY GREY FORMULA

CIL == Glidden
CIL DULUX Int. Latex -Flat
WISPY GREY (50GY 62/029)
Pure White (2110)
Per GALLON
B 0 22 0 Lamp Black
C 0 08 0 Yellow Oxide
D 0 02 0 Thalo Green

Excuse my ignorance... I am finally getting ready to try a paint solution, and I want to try Flat Gray, Poly, Pearl (1:1:1), or the Flat Gray, Poly, Pearl, SM (1:1:1:1). From the screen caps, it looks like GPPSM offers a narrower viewing cone than GPP, but other than that, the differences are slight correct me if I am wrong).

I have an 800 lumen PJ showing on a bright white DIY artist canvas (unprimed, un-gesso'd), so I am looking for something new.

Questions: when you say "It was mixed in a flat white primer" what does that mean? Was it mixed by you, or does it come mixed when you buy it? What percentage is the paint/primer ratio? And what is the brand/model number of the primer?

Thanks...
-T
post #52 of 143
Thread Starter 
Quote:
Originally Posted by T-Bone View Post

Excuse my ignorance... I am finally getting ready to try a paint solution, and I want to try Flat Gray, Poly, Pearl (1:1:1), or the Flat Gray, Poly, Pearl, SM (1:1:1:1). From the screen caps, it looks like GPPSM offers a narrower viewing cone than GPP, but other than that, the differences are slight correct me if I am wrong).

I have an 800 lumen PJ showing on a bright white DIY artist canvas (unprimed, un-gesso'd), so I am looking for something new.

Questions: when you say "It was mixed in a flat white primer" what does that mean? Was it mixed by you, or does it come mixed when you buy it? What percentage is the paint/primer ratio? And what is the brand/model number of the primer?

Thanks...
-T

T
Wispy Grey is a Glidden color and is a fairly neutral gray I am told. What Tiddler did I believe and I'm sure he will post in but rather than having a gallon made just to run some tests he used white matte primer as the base adding LB Yellow and Green. The yellow and green I gather are to undo a blue push that is caused by something in the white I'm assuming.

You are right in your assumption of what the Pearl and SM add to the mix. IMO they both give the paint a combined angular gain increase along with an efficiency increase.

The above you will see the whites and colors stay about the same when viewed on axis to the white sample but on the white sample the blacks are falling off. To get this improvement you pay the price when viewing off angle.

A fairer comparison is to compare it to a neutral gray of the same grayness without the added pearl and SM. That testing was done in the Tiddler link I added this morning to the opening post to this thread.

Personally I'm still using the original mix I had when I started this thread and haven't found improvement yet. That was 22/48 oz LB in a gallon of paint, 2000 lumens on a 120 4:3 screen.

You have a lot less lumens and you didn't mention screen size so I'm assuming you might benefit more from the 1:1:1 or the 1:1:1:1 mixes. Keep in mind the SM adds a gray component to the visual look of the mix. And that gray look is what helps with the perceived contrast.
post #53 of 143
Bud,

The rated 800 lumens is spread across a 16:9 110" screen... in reality, I probably have about 400 actual calibrated lumens.

Just so I am clear, am I correct in assuming that I can just buy Glidden Wispy Grey and just add Poly, Pearl, and SM in the correct ratios and not even worry about primer?

Thanks again...

-T
post #54 of 143
Thread Starter 
Quote:
Originally Posted by T-Bone View Post

Bud,

The rated 800 lumens is spread across a 16:9 110" screen... in reality, I probably have about 400 actual calibrated lumens.

Just so I am clear, am I correct in assuming that I can just buy Glidden Wispy Grey and just add Poly, Pearl, and SM in the correct ratios and not even worry about primer?

Thanks again...

-T

T
I haven't personally tried this 1:1:1:1 wispy gray mixture. And with that big of a screen and 400 lumens I'm assuming you are in total light controlled setting.

I know the wispy gray is one of the lighter grays and the additives should improve gain for you. And the short answer to your question is yes you can just buy the paint using that name and the paint number Tiddler provided. In the lowest luster base. Matte or flat.

If you read this thread or at least the beginning what I was hoping for never happened and that being once someone found success with a mix they would report their results for others to use and build upon. My thoughts were to start with the simplest of grays and go from there. But there has always been little interest in cataloging results.

I wish I could tell you do this mix and you will have the best but I can't say that. And others with vastly more experience never wanted to offer up starting points.

I would say give it a try and report back what you find. You said you were looking for something new over the bright white you are shooting to now. By something new do you mean better darker blacks and you feel you have a little more power than you need on the bright end? I always try and play it safe and mix a small sample when I can and paint a test and view it in several different modes before I commit to the whole screen.

Hopefully someone with a low lumen projector will post that has some feedback for you.
post #55 of 143
Bud,

Thanks for providing additional feedback... appreciate it.

I am in total darkness, but only starting from the late afternoon and beyond. We have 2 6'x6' windows in our dedicated room, and each is covered by those Pleated Shades (look like accordions) that are total Blackout type, so no light passes through the actual shade. Unfortunately, I have some light leakage around the edge of the shade. One option was to put put curtains to block the light spill, and I may still do that.

The main reasons I want to try a painted screen surface: the canvas I am using lets light pass through... I'd estimate about 10%. I really do not want to put up curtains, so I was hoping to prevent all light from passing through the screen (that alone should provide a 10% bump in gain, and even more with a 1:1:1 mix), as well as improve ambient light rejection (there is little ambient light, but any light at all, IMO, reduces blacks).

-T
post #56 of 143
Thread Starter 
T

You are right plain canvas isn't a bad screen surface but it takes a lot of lumens. Light going thru it is pure waste and if you see 10% going thru there is a good chance a lot is getting absorbed in the fibers. With paint you will get a much better surface reflection and it should buy you a lot.

If it was my screen here is what I would do. Seeing the cost of a 1:1:1 mix or 1:1:1:1 mix and knowing how much paint canvas soaks up I would prime it first anyway. Gesso is the recommended thing to prime canvas with but I experimented and found regular latex paint soaked in and bonded to the canvas fine. I would first prime the screen with just flat white or kilz2 primer and try viewing it for a while maybe even take a few screen shots to get a feel where you are with your lumens. Then the process of selecting the next step will be a bit easier IMO.

You will also be able to compare night viewing with the light leakage you will see during the day.
post #57 of 143
Thread Starter 
This thread from day one was about a one can paint solution that anyone in the world could go into any paint store or hardware that has a measured mixing machine and ask for a gallon of paint be made the brand of paint was not as important as the outcome of the mix. We all know you can go to any paint store and find a paint color and ask the mix person I like this color but can you make it out of this different paint company base and they say sure no problem. So what they really need is a code to put into the machine and a base to start with in the correct luster.

I posted the below to another thread and it was somewhat off topic so what I would like to do is bring that discussion over to this thread where it's more appropriate. If anything of substance becomes of it I will then update the opening post to clearly explain what we come up with.
So below is a cut and paste from another thread and the direction I would like to take the efforts of this thread.
---------------------- --------------------------- ------------------- --------------------

I have advocated for a long time forget the silly commercial paint names and forget looking for a magic color chip at your favorite paint store to be a neutral gray. All these paints are formulated to please the eye and in order to do that some subtle color is required. No one paints a room flat black normally and no one wants to paint one a devoid of color neutral gray. I advocated lamp black in white base as did Bombadil

http://archive.avsforum.com/avs-vb/...threadid=344875
http://archive.avsforum.com/avs-vb/...threadid=418361

His first thread was LB and white and he devised a simple numbering system I always liked to identify the level of gray. He then identified that LB and white was not a true neutral and somehow felt raw umber was the magic bullet. I never quite bought into the raw umber but had no way to disprove its claims also.

Now we are learning yellow oxide may be a better pick. That's been a long time in coming and as Tiddler said it's a fall out of the experimentation over in the RGB thread. I don't have access to color testing equipment, but I would hope and ask of the members that do to see if a closer neutral gray can be made of paint store pigments white base, LB, and yellow oxide. The white base being a constant, then some constant proportion of the other two equated to a RGB outcome.

The additional item of improvement I chose to include in my simple solution thread was the addition of poly alone to the paint as a sheen adjuster. That's what I was really adding or trying to add beyond the Bombadil threads. That and a detail of the methodology one could follow to achieve a simple screen paint in one can that is easy to apply and would be adjustable to many projectors and screen sizes with different ambient levels of room light.

Like all things there are limitations to this and it's really for the guy that's able to be around the unity gain maybe a little more or a fair amount less.

One question I have had in the back of my mind and it deals with how pure a RGB number has to be to be considered good. I'm pretty sure a RGB of 180 180 181 would be good but really how bad is a 180 180 185 say?
Does anyone have the ability to look at the average projectors ability to correct for tiny changes in a neutral gray RGB and say we are grasping at straws when we worry about a change of X amount. I noticed the commercial screens tested all are far form neutral based on the exacting standards we seem to be placing on ourselves.

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.
post #58 of 143
Thread Starter 
Here is the data I have to date on lamp black only.
(I believe prof55 did the testing and the data has been widely reposted)

Pure LB = RGB 47 45 49

Mixed in UPW
5/48 LB/qt = RGB 211 207 221
11/48 LB/qt= RGB 201 198 213

Pure UPW= RGB 253 244 253

And we all know pure white 255 255 255
And pure black 0 0 0


Just looking at this small data set quickly all have the highest number in Blue all have middle number in Red and the lowest value is Green.

That's the data now how do we determine the effect of yellow oxide?
post #59 of 143
Quote:
Originally Posted by bud16415 View Post

One question I have had in the back of my mind and it deals with how pure a RGB number has to be to be considered good. I'm pretty sure a RGB of 180 180 181 would be good but really how bad is a 180 180 185 say?
Does anyone have the ability to look at the average projectors ability to correct for tiny changes in a neutral gray RGB and say we are grasping at straws when we worry about a change of X amount. I noticed the commercial screens tested all are far form neutral based on the exacting standards we seem to be placing on ourselves.

I've been curious about this too, and I think a lot is in the eye of the viewer. Here's some quick examples of a 180/180/180 gray graduating to various "pushes". How far off can it be and still look gray to you? For my money, any deviation more than 2 or 3 points is very noticable - but your mileage may vary. Also bear in mind that these are "single direction" pushes. Many of the colors under discussion have more than one color different. And how much the projector can compensate is definitely an unknown...

post #60 of 143
Thread Starter 
Great examples. To my eye a change in 5 is not so bad in a single color. I would suggest when viewing prof55 examples use a couple pieces of dark paper to mask the others and view them one at a time.

Can you make such a gradient on 211 207 221 around the mean of 213
And 201 198 213 around the mean of 204
And also 253 244 253 around max 255

If we were to guess at a condemning limit of 5 before we say a neutral is working against us a great deal I would have a feeling just about any projector could calibrate to that offset.
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