then layer of White paint sprayed over Black paint for contast enhancement??? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 2 Old 07-13-2013, 07:34 PM - Thread Starter
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So, i know for the DIY, when it comes to increasing contrast, one of the best ways to enhance contrast is to either A) use a greyish paint mixture like Silver Fire or such and B) When it comes to having a White paint top coating, you can first spray a grey undercoat then spray your white paint on top of that. And of course, we can't forget, you can do a Light Fusion of sort by spraying a white or grey top coat over a mirror or silver metallic. not to forget that a "white fusion" will also make contrast better but only due to the reentry of the white up kick. But what about having a black bottom coat instead or grey.
For a while i had to project my image onto my dark, flat, brown color i have on my wall. It killed brightness, that's for sure, but it was nice to see the dark colors so enhanced. I finally got my wall painted with a primer, to prepare it for S-I-L-V-E-R, and am enjoying having my brightness back up, but one they i do notice, is that in parts where the primer was a little thinner, due to the this and that, the contrast in that area is little better but still maintains its brightness in those areas where the primer was thinner.. Having the projector image light interacting more with that flat, brown undercoat, gave it a little kick in areas where the colors were darker. Blacks, and blue and so on where deeper.
I know these are the basics of painting when it comes to contrast and most are aware of these aspects, especially for those on this forum who have spent many years to give everyone a chance to have a good screen without having to pay tons for money for a GOOD screen by coming up with such formulas as mentioned above .
I know when everyone wants to get better contrast we usually stick with the greys but I was wondering what about having a small layer of black as a bottom coat then spraying a couple thin coats of White on top, so not as to rob to much whites. This is a big concern for me especially, because I have a 3D projector and when the projector is switched to 3D mode the brightness goes down about 25%, I think. I have the new viewsonic pjd5533w which I only paid $500 for and for that price it's great. It has 3000 lumens and contrast ratio of 15,000:1. But when it comes to paint mixture, I need something that doesn't kill my white so I don't feel like I"m loosing as much brightness, which really, isn't a much brightness but white i guess. But never mind the specs I'm loosing my train of thoughts, lol.
I would think that the biggest problem, of course, would be the extreme crushing of whites. But what if you could spray a high gain black that wouldn't kill it as much or spend some major money for a black diamond BLACK screen then spray a light coat of white over it., still giving awesome contrast and work awesomely in ambient light but giving some whites back to the image due to the white top coat.
Hoping some of the veterines in DIY on here, would give me a take on this. thanks.
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post #2 of 2 Old 07-14-2013, 06:52 AM
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Black is less reflective and more absorbing than a Gray.

Basic Gray & Black undercoats will both will deepen on-screen Black levels via attenuation, but proportionate to their attenuation, the quality of the Whites will drop. There is no escaping that if such basic principles are used.

Certainly a highly reflective gloss Black, such as Piano Black will reflect more than absorb.....but even so, the Top Coat, even a bright white....if it is thin enough to allow the Black undercoating to affect things, is going to show itself as being Gray, and if the Screen Surface is looking Gray, then reflected light off that surface will by nature also be attenuated.

A couple years back I sprayed a extremely reflective metallic coating on top of Black Sintra, to try to ward off that coating's gross tendency to hot spot. And it worked too. However the darker underlying coating tended to highlight the far more reflective metallic composition of the topmost surface, enhancing the appearance of graininess.

That circumstance has been and remains the bane of all the Mfg Screen makers who attempt to combine High Contrast with High Gain. DIY must face that issue as well, but we are able to "Fine Tune" things more readily...and more easily. That is "OUR" advantage.

It has always been the need to balance out surface reflectivity with any underlying surface, be it either reflective or absorptive, that has driven Screen design since day one. For many Screen Mfg, yes...they apply a surface over a Black to avoid light transmission / loss. But usually they do not try to make the underlying surface interact. A few do using various methods, and some past & recent ones appear directly related to design principles we have pioneered on this Forum. (Mirrors / Mylar /Silver Metallic)

DIY Screen making, being dedicated to "one-upmanship" over Mfg, Screens.... has naturally been inclined toward experimentation with ideas and applications that most Screen Mfgs cannot or will not embrace due to cost and pricing constraints. The few who have gone there...their prices reflect such thinking and the eventual costs involved.

You can be sure that almost every possible consideration has already been explored / made in the design and implementation of the advanced DIY Screen apps you'll find on AVS. And while there will be some denials of such, one can tie most all other attempts found scattered about elsewhere to pursue advances in Screen design to such efforts as have been made here. There was a time when those on other Forums would gladly refer others to another source of info, or respect the ideas that come from such and give them credit. But nowadays, it's mostly viewed by some as a competition, as if DIY Screen making is rooted in "selling" people on what application is most valid and worthy of consideration.

To any event, the use of a underlying background's own reflective properties to help augment or attenuate light reflected off a overlying "Top" surface isn't new, it just has always faced limitations due to the existing physics that revolved around the methods that were being embraced. Change up those methods, or refine those that had promise but who had failed due to unresolved issues, and suddenly there can be (...and has been...) a paradigm shift in what is considered possible.

Despite how some others want to view it...that we are ignoring or trying to change the Laws of Physics, what is really happening is that we are finding new ways to work with such Laws, and in some cases, bend them a little.

........and that's how we roll on this Forum.

"They said it couldn't be done. Well, we sure showed 'em otherwise!"
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