Color CRTs have a dot pitch. This tube is perhaps 17" but only good up to 1024*768 or so native resolution. It will have limited brightness (as most high-res color CRTs do) but it does make some of that up with good black and decent contrast.

Deunan wrote on 2024-07-23, 16:13:

Color CRTs have a dot pitch. This tube is perhaps 17" but only good up to 1024*768 or so native resolution. It will have limited brightness (as most high-res color CRTs do) but it does make some of that up with good black and decent contrast.

True. but the problem is that is nothing to do with the resolution, doesn't matter what resolution is its, even i bios whit light colors it exist, i can move around example notepad i windows and they layers stays the same place as if you would have dust on top of the screen.
Sadly i have not find any good way to take a good picture.

The tube is sealed and pumped to vacuum. There can be no dust of any kind in it. Perhaps there is some phosphor degradation due to years of exposure to below-freezing temperatures? Who knows how long and where this was stored. Or it could be just poor CRT quality - late production was like with floppy disks, price was everything to compete with LCDs.

It might even out a bit during use, but probably not much. Just in case avoid turning the monitor with the face up. If there is any phosphor flaking from the glass you do not want it to foul the guns. Other than that - you already have it, so use it. And just in case, you are sure it's not some sort of dirty glass on the front? Do note there might be an anti-static / anti-glare coating, so do not rub it with anything abrasive. You'll get scratches in that layer, or worse. Dish washing detergent or soap on soft, clean rag is the most you can use.

There can be some specs of crap in the phosphors layer. The layer itself is on a rough surface to help with adhesion to it. There can also be burn-in that causes discoloration in affected area compared to rest, usually in brownish hue.
The photo in first post is not showing anything unusual, not without a reference to highlight any differences.

Do those have some kind of anti-scratch or other plastic cover between you and the actual front glass of the CRT that perhaps has come detached? ("CRT cataracts" but I think that's more associated with 1950s television sets)

Just for fun, try and degauss it.

jakethompson1 wrote on 2024-07-26, 03:35:

Do those have some kind of anti-scratch or other plastic cover between you and the actual front glass of the CRT that perhaps has come detached? ("CRT cataracts" but I think that's more associated with 1950s television sets)

I totally forgot antiglare layers, many monitors have them and they are often damaged from use of detergents when cleaning, leading to discolored patches etc.