In our ambient light conditions the SI Zero Edge Slate 1.2 ties with the Elite DarkStar as the two brightest screens of the eleven in this group. This is unexpected due to its gain rating of 1.2. With a luminance reading of 146 fL it is also slightly brighter than the 1.4 gain Black Diamond, which measured 142.
In the first contrast test with side illuminating window light only, the Slate turned in a solid contrast reading of 29:1, almost tied with the Black Diamond at 30:1. So both of these Screen Innovations products ended up in the top 3 in their ability to defeat ambient light from the side. However, once the ceiling floods were turned on, the Black Diamond was able to hold its contrast more effectively than the Slate. In this second test the Black Diamond registered 21:1, almost tied for first place, while the Slate delivered 16:1, a reading that was middle of the pack in a total range between 11:1 and 22:1.
The reason for the Slate's drop in contrast when overhead ambient light was introduced was its inability to hold black as effectively as the Black Diamond. The Slate measured a black luminance of 7.9 fL (the second worst of the eleven) compared to the Black Diamond's first place reading of 5.4.
The Zero Edge Slate also gave us the second narrowest viewing angle of the eleven, at 46 degrees. Only the Seymour's extremely tight 32 degree viewing angle was more restricted. This means that as you move away from the center viewing position the Slate will lose its luminance and uniformity fairly rapidly in comparison to most of its competitors. However, when viewed at center position it tied for first as the brightest image.
The Slate's vertical half angle of 26 degrees was better than most, allowing a bit more latitude in the vertical placement of the projector vis a vis the audience.
In terms of texture and graininess, the Slate matched the Black Diamond and several others in the "modest texture" category.
Our test sample of the Zero Edge Slate came fully assembled with a back LED-lighting system. Its extremely thin edge frame and back lighting is certainly a great visual effect that will appeal to many buyers and it may be a good reason to opt for the Zero Edge Slate over competing products. However, since most vendors offer a variety of fixed and retractable mounting options and LED back-lighting systems can be acquired independently, we are limiting this review to issues pertaining to each screen's actual image performance characteristics rather than the mounting and presentation options.
In this evaluation the Zero Edge Slate performed at its best when viewed at or close to the zero degree viewing axis in situations where directional ambient light comes from the side rather than above. If this describes your anticipated viewing situation, we'd make sure to get a quote on the Slate, configured as you'd want it. However, the Slate is not quite as versatile as the SI Black Diamond which in our testing defeats ambient light from above more successfully. The Black Diamond also has a marginally wider viewing angle than the Slate, and will likely be the more accommodating solution for many random ambient light situations.