Quote:
Originally Posted by Hughman /forum/post/21227041
If one of the screens attributes is off-axis light rejection and a room suffers from off-axis light contamination onto the screen such as might be encountered from light bouncing off a wall, ceiling, or floor close to the screen then in practise the screens inherent qualities will help maintain the attributes you list.
Yes, exactly. It's all those caveats that are important. "better black levels and shadow detail" are not qualities inherent to the screen. Rather, characteristics of the screen can help one realize better black levels (and better ANSI)
under certain conditions - depending on room reflectivity, the projector, picture settings, ambient light etc.
This is supposed to be a place were we educate ourselves about the science and realities of how our equipment works. Unless we make these distinctions, at least sometimes, people will not be educated, but instead will pick up fallacious concepts (which I don't think helps anyone).
The Stewart Firehawk has similar attributes as the HCHP screen, insofar as it is a darker substrate, has gain coating, rejects off axis light and aims the light toward the viewer (although in an angular reflective manner). So someone not understanding how projection works may want to say "The Firehawk will inherently give you deeper black levels, better shadow detail and better image depth."
Yet the image on my
1.3 gain white screen (Stewart ST-130) is better in all those respects (black level, shadow detail, image pop and depth) than on a projector demo I watched on Stewart Firehawk screen, last week.
Why? It has to do with the combination of screen, screen size, room reflectivity, projector, picture settings etc.
This would be puzzling if one had the misunderstanding that black levels and shadow detail were inherently better on a specialty darker screen (like the Firehawk or HCHP). But it makes complete sense when we understand that those PQ's aren't inherent to screens themselves, but to the combination of variables that we need to understand when setting up a projection system.
(BTW, the idea that dark specialty screens "inherently" produce deeper blacks and a more dimensional image seems so widespread that even people who do AV for a living can fall for it. For instance, a local large AV retailer/installer company had raved for quite a while about the image they were getting using the Black Diamond screens with their clients. They thought the screens made black levels and image depth look amazing, and they talked about this as if these were attributes of the screen itself. Then they came to my house and saw the JVC projector - a product they sell as well - in my room, on my regular 1.3 gain white screen and were completely blown away. Said they'd never seen anything quite like it in terms of pretty much all the PQ parameters and made them start re-thinking their views on screens again. Why? I have a room optimized to get the best out of the projected image...which reminded them that many of the qualities they were imparting to the Black Diamond screens weren't inherent to the screen, but were the result of all the variables of room/projector etc).
Hughman, I'm not telling you things you don't know, of course. I'm just making a pitch for the educational virtues of being more precise in how we talk about these things. At least occasionally I think it's worth untangling these concepts from the way many of us describe equipment on this forum.
Cheers,