[Chrismaniac]

Hello everyone!

I'm new here, but I've been reading the forum for a very long time and today I'm asking you for help, namely once I saw a table with the color spectrum (RGB) of commercial projection screens, but I can't find it for anything, I searched the whole internet and there is none.

I don't remember on which forum it was posted, because I saw it a few years ago, but surely someone from this forum knows it, so I'm counting on pointing to the source, I will be very grateful.

Kind regards..
Chrismaniac

 

[Chrismaniac]

And an additional question I have - why commercial screens, in particular Stewart, have a reduced level of green, as a consequence of which these screens have a magenta tint, not neutral? 🙂

 

[Da Wiz]

When you say "commercial" screens, are you talking about screens for movie theaters and other large venues, or are you talking about screens manufactured for home theater? There is a shakeup in movie theaters with the limited luminance available from projection giving them fits trying to compete with 85-inch flat screen TVs that sell for less than $3000 and sometimes for less than $2000, that have 30 times more luminance as compared to a projection screen in a movie theater. All that extra light us used to make HDR look spectacular on big TVs and to expand the range of colors that can be displayed. Movie theaters, meanwhile, cannot deliver meaningful HDR or expanded color gamut because there's just not enough light to work with. Reducing "green" light from a movie projection screen doesn't make a lot of sense since that would perceptually "dim" the images on projection screens (72% of the light we see is green wavelengths, only 21% is red light, and only 8% is blue light). I've been measuring and using screens for 30 years and have never measured a screen with too little green light reflected. A few times, I've run into screens that were a little too blue, but those were intended to be used in theaters where the images from the screen/projector were calibrated. It doesn't much matter what the color balance of the projection screen is if you are going to be calibrating the projector/screen combination. I mean, within reason! You could always come up with a screen with too much color shift to be calibrate-able.

 

[Chrismaniac]

@Da Wiz I mean, for example, Stewart screens and data available on the web, which show that green is withdrawn from red and blue by about 6 points. On the other hand, another source gives practically equal RGB values, so now I don't know who to believe?! 🤷 Thank you for your comment. 🙂👍

 

[Da Wiz]

"Consider the source" -- not everybody knows what they are doing when it comes to measurements. How do they know it wasn't the PROJECTOR that had the green deficit... or that the projector was calibrated using a screen with more green light than expected, so when they measure a proper screen, it only LOOKS like there's a deficit in green.

 

[Da Wiz]

Also, 90% of everything online is **. So there's always that...

 

[ggil0344]

Yes, Da Wiz, what ever happened to Diogenes?