Ambient Light: Daylight vs. Bulbs & how it affects your screen

I've been doing a lot of testing and watching of my new XFS screen and as a semi-professional videographer I know that daylight and interior lights are different color temperatures. I've also noticed that these two kinds of light react to my screen quite differently. Daylight is much less destructive on the image. With my large windows unblocked tons of light comes in, but it doesn't ruin the image as bad as blasting my screen with my 300 watt IKEA light. I don't know how many watts God's lights are but it's plenty more than 300 Why would more daylight be less destructive than less bulb light?

My theory is color temperature. Daylight looks more naturally white. When daylight ambient light affects my screen sure it ruins contrast ratio, but it isn't shifting the color tone of the whites and blacks on the screen. Interior lights, however, have a strong yellow cast to them. Even a little bit of this light, while only marginally affecting the contrast ratio, instantly shifts the color of whites and black, pulling them to yellow. A moderate amount of interior light makes whites and blacks much more yellow and seems to ruin the image in two ways (CR and color) rather than daylight only ruining CR. So why did I post this? I'm no expert so I'm hoping others might share their thoughts on this.

Why should anyone care? Well, from the video business I also know they make bulbs that are created to be daylight balanced. The color temperature of these daylight balanced bulbs is the same as daylight. If you could use these bulbs in your theater you'd be able to avoid the color shifting of normal interior lights. To me the CR loss doesn't seem nearly as bad if the light hitting the screen is also white. That way whites stay white and blacks just get more gray. Eventually your blacks cannot get any lighter than your screen color. So if you have a gray screen the blacks can't get lighter than that color and white is well white, it just stays white. With daylight ambient light hitting my screen the image seems to hold together much better even with massive amounts of ambient light.

On a side note, I think this is one reason why ambient light rejecting screen makers like DNP choose to photograph their products with lots of DAYLIGHT ambient light rather than bulb light. The DNP video demo was shot outside in broad daylight.

Please tell me what you think?

Here's a thought. Well two thoughts.

1. replace all your ambient lighting bulbs with daylight balanced light bulbs. This will throw a pure white light and be much less damaging to you screens image. I don't know what kind of options are out there for home use daylight balanced light bulbs - it's kind of a professional video/film lighting thing, but they do make gels that do the same thing. Cut them to size and figure out a way to hang them in front of your normal lights. The gels filter the light changing the color temperature to daylight. Don't tape them to the bulb, that might burn your house down but gels are made to withstand the heat of 1,000 watt Arri studio lights. They just need a little space to breath.

2. what about using the painted acrylic mirror technique pioneered by MississippiMud only frost the screen with an almost black layer. The trick would be to get the black thick enough that low ambient viewing light wouldn't be reflected much, but thin enough that the more powerful light of the projector could get through and be reflected by the mirror. This should also improve black levels. The trick would be getting it right so whites would be able to be reflected back and still look bright white. Any thoughts on whether this could work?

You just said so much cool stuff about paint that I can't begin to understand what it even means.

Looks like I need to pick up some GE reveal bulbs. My IKEA light doesn't have the standard round bulb connection but uses the taller more candle-like shaped bulb with the smaller connection. Hopefully GE has reveal bulbs in this size. If HD has them, I'll post a screen shot comparison between regular normal bulbs and the Reveal corrected bulbs and how they react to screens.