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  Topic Review (Newest First)
11-30-09 03:55 PM
1canuck2
Re: Help me pick a DIY paint

FYI for those reading this thread, I went with an experimental formula (currently called HTS-X2) that Harpmaker provided me. The results can be seen here
11-10-09 11:42 AM
wbassett
Re: Help me pick a DIY paint

Quote:
1canuck2 wrote: View Post
I am basically looking to roll a close proximity to an N8 and have the variability be in the shade of neutral, not in the RGB "mix". If it ends up as N8.27, then, my eyes will tell me if its good. As I said yesterday, I am actually quite happy with the results from Kilz2. So any improvement on this would be a great thing.
Odds are if it ends up as N8.27 verses N8... you will never notice a difference! Some people will, but most won't.

The lowest perceivable difference that some people have been able to detect is a .1 change in tint. These would be your eagle eye people though. Most people will not start seeing a difference in shade/tint until up around the .3 area, and with a projected image, not until around the .5 range.
11-10-09 11:34 AM
wbassett
Re: Help me pick a DIY paint

Quote:
1canuck2 wrote: View Post
Wow wbasset, quite the in-depth explanation there. While some of the more technical aspects of the art and science will likely always evade me, I can follow along well enough, especially with the helpful posts from you guys.

I'll sum up your post for you though: K.I.S.S. It applies to much of life, not just screen formulas!

One question/thought occurred to me when reading your post, what is the expected variability from the paint store? How precisely calibrated are the pigment machines from store to store? Any formula that uses as "non-base" paint (i.e. where someone in the store will shoot pigment into a base to give you Winter Mist or whatever) is surely at the mercy of:
1. The accuracy of the pigment shooting machine
2. The care or skill of the employee mixing the paint
3. Other factors (such as subtle diffs in pigments from time to time/region to region, etc)

Even the base paints could "drift" over time as the factory that produces them makes changes...

It strikes me that we encourage a fairly decent amount of anality in the care with which we add our ingredients, but there's no guarantee that each ingredient is identical to that of the formula creator.

It certainly seems like you have mitigated as much of this as you can, especially by minimizing the places in which the user can screw it up (e.g. multiple colour pigments) but there's still some elements that are out of everyone's control.

I am basically looking to roll a close proximity to an N8 and have the variability be in the shade of neutral, not in the RGB "mix". If it ends up as N8.27, then, my eyes will tell me if its good. As I said yesterday, I am actually quite happy with the results from Kilz2. So any improvement on this would be a great thing.
This is always a very legitimate issue when it comes to house paints. For the most part we have seen pretty consistent results, but now and then we see a batch or sample someone sends that is off and it's due to the base being off. Why it's off is the variable. It could be the machine, or it could be the staff person that did the mixing.

One thing we did to try and compensate for this is that our mixes are tested and retested throughout development and not only are they neutral, they are well within the neutral tolerances. This doesn't mean if a store staffer messes up royally that things will be okay, but it does seem to cover minor variances. In other words, with such tight tolerances a little variance won't matter because we will still be in the neutral zone.

Think of it as a target...
Above is the CIE Chromaticity graph with our neutral tolerances. The red dot is our D65 reference and of course the bullseye. Now- things will remain neutral all the way out to the inner most circle. Anything within that ring is definitely a neutral gray.

The next ring out is the 'near neutral' ring. Anything in this area is very close to neutral but not quite a true neutral. For most people, they won't be able to tell much if any of a difference. Of course the closer to the bullseye is always better...

The outer most ring is the 'acceptable' ring. Anything within here certainly will be usable for a screen but not quite as good as options that are closer to our D65 bullseye. Anything outside of the acceptable ring is a roll of the dice... it may or may not work well as a screen and depends on the setting, and projector. For the most part screens outside the target area are the ones that start to exhibit a warm or cool push and starts making calibration more difficult to do. In some instances for example, if the screen leans blue or cool, and the viewer prefers a warmer or reddish image, they simply may not be able to dial it in to their liking. If the screen is D65, the user can calibrate the projector any way they want... although I prefer as close to D65 as possible!
11-10-09 11:20 AM
Harpmaker
Re: Help me pick a DIY paint

Well stated 1canuck2.

The variables that you mention are why when we develop a screen mix we try to get it an close to perfectly neutral as we can, this helps to build in a "fudge factor" so that variations that must creep into the equation due to factors such as you mentioned can be taken in stride and the final mix still well within our neutrality standards.
11-10-09 09:40 AM
1canuck2
Re: Help me pick a DIY paint

Wow wbasset, quite the in-depth explanation there. While some of the more technical aspects of the art and science will likely always evade me, I can follow along well enough, especially with the helpful posts from you guys.

I'll sum up your post for you though: K.I.S.S. It applies to much of life, not just screen formulas!

One question/thought occurred to me when reading your post, what is the expected variability from the paint store? How precisely calibrated are the pigment machines from store to store? Any formula that uses as "non-base" paint (i.e. where someone in the store will shoot pigment into a base to give you Winter Mist or whatever) is surely at the mercy of:
1. The accuracy of the pigment shooting machine
2. The care or skill of the employee mixing the paint
3. Other factors (such as subtle diffs in pigments from time to time/region to region, etc)

Even the base paints could "drift" over time as the factory that produces them makes changes...

It strikes me that we encourage a fairly decent amount of anality in the care with which we add our ingredients, but there's no guarantee that each ingredient is identical to that of the formula creator.

It certainly seems like you have mitigated as much of this as you can, especially by minimizing the places in which the user can screw it up (e.g. multiple colour pigments) but there's still some elements that are out of everyone's control.

I am basically looking to roll a close proximity to an N8 and have the variability be in the shade of neutral, not in the RGB "mix". If it ends up as N8.27, then, my eyes will tell me if its good. As I said yesterday, I am actually quite happy with the results from Kilz2. So any improvement on this would be a great thing.
11-09-09 05:03 PM
wbassett
Re: Help me pick a DIY paint

Quote:
Harpmaker wrote: View Post
While they say "never say never", I simply cannot think of a reason we would ever have a formula that called for separate RGBY pigments such as the "scary" (good term ) mix you alluded to; there is simply no rational reason to do so.
The rational, or sham, has always been that the Red, Blue, and Green pigments interact with the projected light in a 'specially designed and engineered way' that makes the screen better than anything else. I find that extremely unlikely right away considering the person that says this has never had a single reading taken on anything. It's hard to 'special engineer' something without actually using science or taking readings to verify the results! Without conducting QC tests, it's nothing more than trail and error based on personal preferences and eyes. D65 neutral is the industry standard for a reason and without testing, a person will never know if they hit a bullseye, are close, or a mile off.

Once again, and this has been stated many many times too... if a spectrophotometer sees something as neutral, it is neutral. It doesn't matter how it was made, it is neutral. So an RGB neutral gray (extremely difficult to make in a laboratory let alone by eye without any equipment- one thing off even in the slightest and you don't get neutral) is no different than a neutral gray made from RYB, or (a mind blower) Yellow and Blue, or any other combination of pigments that result in a final product of neutral gray.

As ZMan mentioned in another thread, there is one thing that does kind of come into play, and that is pigment purity. The purer the pigment, the more it will reflect that particular spectrum. This is because it doesn't have other impurities absorbing the light, so a higher percentage gets reflected back. It also makes things easier to reproduce with a lower DE. So if you make a neutral gray using as pure of pigments as you can get, you will have the brightest screen possible before even applying an optical coating! This is because you don't have a lot of impurities in the mix that are absorbing the spectrum you actually want reflected back. The best balance is when the lab 'a' and 'b' channels are under 1.0 and equal but opposite in polarity. These spectral curves are the flattest of all I have seen.

We have been able to consistently get a low DE with house paints, but we have also seen some wild variations too. Even professional house painters have a trick they do. They never use one 5gal bucket until it's empty and then open another... they always pour buckets together and mix them up. This way they get a blend between the two batches so when they run out of paint you can't tell where they opened the new can. House paints are okay, but probably the lowest quality paints out there aside from craft paints (note- there is a huge difference between craft paints and artist grade paints).

Black Widow, Scorpion, and C&S may look simple, but a lot of hard work went into making something complex simple and repeatable by anyone!

So to everyone out there, don't ever forget that just because something is complex or complicated doesn't mean it is the best, it is just more complicated is all. And the more complex something is, the higher the odds are that something will go wrong. I can also say with very high confidence that repeatability with such an item is almost non-existent because a little too little color here because not everything came out of the syringe, or a tad too much color there... I'll say each and every screen made with more than a couple components will all have different readings. The method simply is not repeatable, at least not within an acceptable DE I should say.

Nobody is saying everyone has to take readings if they want to play around with DIY screens. It's when people start saying something beats everything hands down is when some specs and proof is needed. Plus we did the hard work so users don't have to!
11-09-09 04:10 PM
Harpmaker
Re: Help me pick a DIY paint

Quote:
1canuck2 wrote: View Post
I'd be prepared to give it a try. The theory is sound in that C&S is already well tested and adding a N6 shouldn't skew it if it is a "good" N6. Measuring the N6 is no biggie on the assumption that the impact of mis-measuring it slightly simply affect the resulting N# as opposed to skewing its R, G or B. Is that good logic?
That is correct. A neutral added to a neutral equals a neutral.

Quote:
So if, for example, you say "take 40oz of C&S and add 5oz of this N6" and I end up adding 4.9oz, then I would simply get an N8.1 instead of an N8, but still a neutral colour. The custom measures in the other formulas are more "scary" because adding slightly more of the red than the green has an impact in the neutrality of the resulting mix.
Again correct! Adding too much or too little of the N6 would only affect the shade of the resulting mix and not the color neutrality. While they say "never say never", I simply cannot think of a reason we would ever have a formula that called for separate RGBY pigments such as the "scary" (good term ) mix you alluded to; there is simply no rational reason to do so.
11-09-09 03:32 PM
AH Theatre
Re: Help me pick a DIY paint

Quote:
wbassett wrote: View Post
mech you know why it is always pushed don't you? Especially since the person that pushes it used to be a die hard roller...

It has very little to do with it 'being the best'. I fully agree that it does make a smoother surface, but we also don't necessarily need a glass smooth surface. Some surface texture helps to diffuse the light, too much of course is bad. My opinion is the more complicated people make things look, the more dependant others are on that person for help.

Spraying has it's own set of issues, especially for someone totally new to it. The number 1 problem- RUNS. Now... I know exactly what the master spraying would say to that. 'If you use the sprayer right and take your time and listen to advice you won't have any problems with runs!' Interestingly... I can say the exact same thing about rolling!

Don is right. It is a matter of personal preference. I know a guy that can use an adhesive roller and could get a coat of paint down so smooth you'd swear it was sprayed glass. I never could get it that smooth myself, but he sure could.
I agree with you Bill, theres a lot of variables when spraying (gun settings, air pressure, thinning) and unless your experienced it's too easy to make a mistake, the trade off between a sprayed screen and rolled is minimal and if your sitting a normal distance back it's near impossible to tell the difference IMO. FWIW, I'm fairly experienced in spraying but I still opted to my roll my screen.
11-09-09 03:23 PM
wbassett
Re: Help me pick a DIY paint

Quote:
mechman wrote: View Post
Using the Wagner CS is no different than an HVLP with a compressor - over spray wise. Very little travels very far. I'd guess most stays within 4 feet.

And I agree with Bill, if you can paint a wall, you can paint a screen. No sprayer should ever be required.
mech you know why it is always pushed don't you? Especially since the person that pushes it used to be a die hard roller...

It has very little to do with it 'being the best'. I fully agree that it does make a smoother surface, but we also don't necessarily need a glass smooth surface. Some surface texture helps to diffuse the light, too much of course is bad. My opinion is the more complicated people make things look, the more dependant others are on that person for help.

Spraying has it's own set of issues, especially for someone totally new to it. The number 1 problem- RUNS. Now... I know exactly what the master sprayer would say to that. 'If you use the sprayer right and take your time and listen to advice you won't have any problems with runs!' Interestingly... I can say the exact same thing about rolling!

Don is right. It is a matter of personal preference. I know a guy that can use an adhesive roller and could get a coat of paint down so smooth you'd swear it was sprayed glass. I never could get it that smooth myself, but he sure could.
11-09-09 03:14 PM
1canuck2
Re: Help me pick a DIY paint

Quote:
Harpmaker wrote: View Post
If you are interested, I should be able to come up with a N8 version of the experimental mix using standard C&S and a N6 paint, but it might take 2 or 3 days (I have to wait for the paint to dry and cure before taking spectro readings). Keep in mind this mix is untested under projection.

To get a N8 with the C&S/N6 mix you will probably have to measure out the N6 paint.
I'd be prepared to give it a try. The theory is sound in that C&S is already well tested and adding a N6 shouldn't skew it if it is a "good" N6. Measuring the N6 is no biggie on the assumption that the impact of mis-measuring it slightly simply affect the resulting N# as opposed to skewing its R, G or B. Is that good logic?

So if, for example, you say "take 40oz of C&S and add 5oz of this N6" and I end up adding 4.9oz, then I would simply get an N8.1 instead of an N8, but still a neutral colour. The custom measures in the other formulas are more "scary" because adding slightly more of the red than the green has an impact in the neutrality of the resulting mix.
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