DIY "infinity contrast" TV – with 100% recycled parts [video]

My experience with laser projectors, is that they work great, but have very weak beams (for reasonably portable ones).

I need it to be something I can toss into a backpack (along with a bunch of other stuff), and be around 1000 lumens.

Not just lumens, either. The color needs to be good, the resolution needs to be (hopefully) greater than 1080p, and it needs to be usable in a semi-lit room. I don't care about speakers. I use projectors as a speaking aid.

I've been using a tiny InFocus LCD unit that's great, but a little anemic (1080p/750 lumens).

The promise of a laser, is that you can project it against a cinder-block wall, and it will stay in focus, and show great color.

They improve color gamut coverage and color volume, but I would not say accuracy. It's much harder to get an RGB laser projector accurately calibrated than an old mercury lamp or even single blue laser / yellow phosphor projector.

I think you can go to an optometrist and get glasses that will achieve the same effect.

I'm nearsighted and wear glasses when I watch a play/movie/etc. with faraway detail, but I wear a second, different pair of glasses when working in front of a close screen. They don't make anything sharper, but I have zero eye strain now while working. My optometrist says it's a common thing in your 40's to start to need that.

I use a projector and TV side-by-side as monitors. The TV provides better contrast during the day. Unfortunately, the projector model I use—Dell S718QL—has been discontinued. You can look at reviews of recent ultra short-throw (UST) models such as ones from Epson, Hisense, LG, or Samsung. For best results, pair a UST projector with an ambient light rejecting (ALR) screen.

Projectors are never infinity contrast as they cannot turn off individual pixels. Projectors have a single constant light source to all pixels like a non local-array dimming TV. It's entirely up to the imaging panel to modulate the pixels, and none of the 3 panel types can block all the light for a pixel.

FIY, current substitute title (using DeArrow chrome extension) is "DIY Rear-Projection TV - Recycling Broken TV And A Projector"

Black color coming from projector isn't full black either https://www.projectorreviews.com/articles-guides/projector-b...

That's not true at all. Black on a projector is still projected light, especially with a DLP which have the worst contrast ratios of the 3 projector types (DLP, LCD, LCoS).

What he is making here is a dual panel display. There are actually some LCD monitors that use this concept of 2 separate panel layers each providing their normal contrast resulting in a multiplicative effect.

For the video posted here, the DLP is probably at best 1000:1 and the cheap old LCD is also maybe about 1000:1, so you get about 1 million:1 which is a lot, but not technically infinite like self-emissive display that can turn off the pixels completely for sections of the picture like OLED and microLED.

The projector lens's optics (coatings, materials, etc.) will have been designed and engineered to have a specified contrast ratio.

So yes, if the internal light engine of the DLP truly reflected all light away, then, if it outputs zero photons for full-screen black, you could say the projector outputs zero photons.

However, the DLP is not 100% effective; the interesting images will have a mix of bright and dark areas, and the lens and software image processing will raise the black levels above zero.

Source: I worked at BrightSide Technologies before and after the acquisition by Dolby Laboratories and learned about DLP lens limitations from the engineer working on DLP+LCD based HDR displays.

Ignoring the fact that the projector doesn't get to true black (noted by smusamashah), and supposing there's no diffusion that spreads the light of a pixel out to surrounding areas of the display panel, it would be possible to say that the display has infinite contrast, I suppose that is true.

Contrast is important, but alone it is useless. You could have a display with only two levels: black and white, and if the black is perfectly black, then it's infinite contrast (any level of white, no matter how dim, is infinitely brighter than total black), but 1-bit color would be useless in reality for home theater.

To make infinite contrast useful, it's necessary to have HDR as well to take advantage of having very dark and very bright areas both able to be represented with detail. Plus having sufficiently bright maximum brightness so that the brightest highlights can really shine.

There's 3 components:

1. a TV or monitor diffuser

2. a sheet of LEDs

3. a power supply capable of driving those LEDs. Typically a 12V supply is sufficient (I don't recall if he goes into power supply sizing).

If you're comfortable with learning some things (soldering in this case), you'll be able to pull this off pretty easily.

I guess I missed it and was hoping for a deeper dive.

and don't forget to re-synchronize the audio!

meh, he doesn't really address the issue. He just mentions using OBS to threshold the image and dilate the resulting regions.

That raises a lot of other questions: He obviously feeds two different videos to the displays. How is this done? Does it add latency, does it work with, let's say, Netflix DRM? Are the two videos even in sync or is the obs post processed feed always N frames behind (think of the transition between barely lit and bright scenes)?