What is the difference between non 4K screen and one marketed as a 4K screen. is this for real or just marketing. Planning on installing an Optoma UHZ65 on 120" screen in completely dark room. Budget less than $2000 for screen?

That is SUCH a good question! Brother Google explains at [Link: projectorscreen.com].

Basically, if the pixels you're projecting are smaller than the bumps on the (textured) screen, it's not possible for an image to be accurately displayed on, and reflected from, the surface.

The distortion they show is both caused by reflections not coming back off the screen at the complement of the angle they're projected at, due to bumps, and bright and dark spotting caused by the same thing.

There are a few other illustrations that show more of what's going on.

This entire thing does not address the question as to whether this "fuzz" might consists of areas of different brightness too small for the eye to perceive.

Also check out and think about the videos that come up on youtube when you search for "your eyes can't see 4k." Three videos by the same guy, but under the three different accounts Knowing Better, Bullet Barry, and Bearded Wonder make me think this guy must be even more irritating than Fins and me. even if he (Barry) knows what he's talking about.

Ha ha I asked myself that very questions. I dunno, maybe the info Ernie referenced is valid. Whether an end user could really tell the difference is debatable I should think.

I think it's debatable, too.

That website has photos showing the unevenness of the white on different non-smooth screens, but the photos are labeled as "from two feet away" with no reference as to how wide a section of the screen we're looking at. They've missed the main point of what they're trying to show by not giving us any idea of the scale.

Judging from the lack of response it's probably something not too many people have thought about....I'm thinking if the relationship between screen texture and pixel size creates a blur you have to consider the texture to pixel ratio as the screen size grows with the pixel size. Perhaps if the screen is big enough the effect becomes less relevant as the pixel size would be so large compared to the size of granules or bumps in the screen. Also if the ideal screen should be smoother and flatter, how does an acoustic transparent 4K screen work? Wouldn't it have holes or a weave pattern that would interfere with proper reflection?

The acoustic screens ABSOLUTELY have weave patterns.

A few years ago we did a ridiculous system in Saudi Arabia. DPI Lightning projector, sixty feet from lens to screen. I can't remember the exact screen dimensions, but it was a 2.35 about 15 to 18 feet high.

Before we accepted the screen from Stewart Filmscreen, we rented a small hangar at the Torrance Airport (the Stewart brothers fly planes and the plant is only a mile away), temporarily hung the screen, used a fork lift to pick up the projector on a pallet, and backed out of the hangar until the image filled the screen. Whatever Stewart had done, there was not even the teeniest bit of moire.

This is where A/V is fun. Renting a hangar. Backing out of it to get the full projection distance... packing it all up again. And of course a bit of a crowd on hand just to see it.

I think Integrators have been sworn to silence about this.

Did I come here to be a technical on Ernie? Well maybe.

Stewart film screens absolutely do not have "weave" patterns. They are all perfed and yes they do different perfs for a 4K intended screen than a 1080P intended screen

Where can I get some 4K Screen Goo paint? All they show is the 1080p paint.

That's funny.

You just paint it 4 times.

Smoothness of the screen surface. (as the link explains)

BUT that doesn't mean a thing when it comes to marketing. Anyone can slap any label on something they want to. There's no way to measure it. "Our screen is under .03 bs units therefore it qualifies as a 4K screen."

If the projector's optics are cheap, they're more likely to muck things up than most any of today's projector screens will.

I'll have to upgrade to 8K at some point.

You should. Accuracy is what matters.

Absolutely right. It was the perf pattern that could have caused a problem.

As I was typing that I wondered how the hell they could get a weave pattern when they spray the screen material up onto the ceiling to make the screen, then peel it down off the ceiling. But I just kept on typing....Of course, I can't imagine how they get the perf pattern in there, either. But yeah. Perf.

Not entirely true, Stewart now has the Harmony woven screen material.