New "laser" screen from Harkness (also: When should an undamaged screen be replaced?)

[Darin Steffl]

Go to the demo. It costs a good chunk of money to attend CinemaCon so never feel bad.

We're going to replace our screen this year and I was leaning towards Severtson SAT-4K because of its fine weave and sound performance. We're also going to laser so I thought with a weave instead of holes, the speckle will be less of a problem. Can anyone compare the two screens and give feedback on which one is best for 2D only? No 3D for us.

[Mark Gulbrandsen]

Sailmakers lofts might be a decent parallel to "imagine".

Several times in past years I've re-used large screens when theaters are twinned by taking the original screen to a sail shop, and in one instance to a Canvas shop, and having it cut down and re-grommeted. But I would only do this if a screen was matte white, in near perfect condition, and not more than say three years old. The canvas and sail shops always did s great job, and the cost was more reasonable than you might think.

[Mark Gulbrandsen]

It's a white Harkness screen, I'm not sure what the gain is, though -- maybe Mark G. could chime in on that since he installed it back in the day!

Pretty sure it's a 1.0 matte white screen Mike. It originally went in around 2007 or so. We had to take it back down so the carpenters could build the baffle wall. So the screen has actually been hung twice...

[Steve Guttag]

Daren, speckle has to do with your eye's own optics and the wavelength of the light and the whole interaction there. What a weave screen would do is break up Morie where the grid like nature of the image and the grid like nature of the perforations in a screen will set up a natural interference pattern. They are two different optical issues. Note, things like microperf can help or make worse Morie as it is the relationship of the two grids.

I may be mistaken but I thought that Severtson's SAT-4K stuff was for screens on the smaller side (home cinema size) more than larger screens used in typical cinemas. A quick check on their web site has them state that a 15-'10" height as "massive" for the screen. So, if your screen is smaller than that, it should work. A gain of 1.2 is a pretty good target, as well (try to stay away from any gain above 1.3). Also beware, while NIST has a definition of Matte-White...screen manufacturers are pretty loose with the term. They'll call most any screen with a 1.0(ish) gain and white as matte-white. If they also mention a "half-gain angle" with a "matte-white" screen...it probably isn't matte-white and has gain like characteristics (hot spotting/light concentration). Screens with less than 1.0, often called "High Contrast" grey screens can have gain like characteristics too (and most often do). The only thing that makes them "high-contrast" is that it takes more light to light them up...so, they reject ambient light. if you use a brighter projector to overcome the lack of reflectivity, you get a net better contrast due to influences of ambient light. Think of those like noise reduction, but for light. Pre-boost it on the projector so that the screen will reduce it back...plus reduce the ambient light's effects.

[Gordon McLeod]

I wonder how te long gone protolite screens would handle speckle