I happen to have a stereo microscope at my desk, so I put my Pixel 9 under there. At 100x mag (10x ocular x 10x objective) it looks like there are 3 layers: as I move my head around slightly (so the image is moving over my retinas), the blue moves faster and the red almost stays still, with green somewhere in the middle.
How does a screen work?
41–50 of 111 posts
Re: How does a screen work?
#42Earlier quoted context omitted.
That slo-mo video is somewhat misleading, though. The phosphor glows for a good while, so there is a reasonable chunk of the image that's visible at any given time. The problem in that video is that the exact location the beam is hitting is momentarily very bright, so they calibrated the exposure to that and everything else looks really dark.
The phosphor still drops off very quickly [0][1][2], roughly within a millisecond. That’s why you would need a 1000 Hz LCD/OLED screen with really high brightness (and strobing logic) to approximate CRT motion clarity. On a traditional NTSC/PAL CRT, 1 ms is just under 16 lines, but the latest line is already much brighter than the rest. The slow-motion recording showing roughly one line at a time therefore seems accu…
I definitely like my new 240hz 4k oled HDR monitor, though. They're getting there! The data rate it's pushing through the displayport cable for uncompressed 4k HDR is something 80gb/s though. Absolutely mind boggling. Huge upgrade from my 1440p 165hz IPS monitor that had huge amounts of smearing when playing games.
Re: How does a screen work?
#43CRTs are still slightly magical to me. The image doesn't really exist. It's an illusion. If your eyes operated at electronic speeds, you would see a single incredibly bright dot-point drawing the raster pattern over and over. This YouTube video by "The Slow Mo Guys" shows this in action: https://youtu.be/3BJU2drrtCM?t=190
To me the magical part about CRTs is color. I don't quite understand how the shadow mask works. Like, yeah, there are three guns, one for each color channel, and the openings in the mask match their layout, and somehow the beam coming out of each gun can only ever hit its corresponding phosphor dots. Even after being deflected. But... how? Also, wouldn't the deflection coils affect each of the three beams slightly di…
For me it was the opposite. Learning how a monochrome CRT requires no mask sort of destroyed my world view of what a display had to have. pixels(even the quasi pixels as found in a color CRT mask) were not actually required or present.
As a result monochrome terminal text has this surprising sharpness to it.(surprising if you are used to color displays). But the real visual treat are the long persistence phosphor radar scopes.
Re: How does a screen work?
#44See also the author's page linked from the post. More very well-done content
https://typefully.com/DanHollick
Re: How does a screen work?
#45Earlier quoted context omitted.
That slo-mo video is somewhat misleading, though. The phosphor glows for a good while, so there is a reasonable chunk of the image that's visible at any given time. The problem in that video is that the exact location the beam is hitting is momentarily very bright, so they calibrated the exposure to that and everything else looks really dark.
The phosphor still drops off very quickly [0][1][2], roughly within a millisecond. That’s why you would need a 1000 Hz LCD/OLED screen with really high brightness (and strobing logic) to approximate CRT motion clarity. On a traditional NTSC/PAL CRT, 1 ms is just under 16 lines, but the latest line is already much brighter than the rest. The slow-motion recording showing roughly one line at a time therefore seems accu…
I'm not quite sure what you're saying here. My assertion is that a visible image persists on the screen longer than it appears in the slo-mo clip. You can just point a camera with an adjustable shutter speed at a CRT and see it for yourself. Here's an example (might need to copy the URL and open in a new tab, they don't like hotlinking):
https://i.sstatic.net/5K61i.png
The brightly-lit band is the part of the frame scanned by the beam while the shutter was open. The part above is the afterimage, which, while not as bright, is definitely there.
Re: How does a screen work?
#46I have to take issue with the usage of the terms "pixel" and "subpixel" with regards to CRT. CRTs do not display discrete pixels . They display discrete scanlines , each one made up of a smoothly varying voltage across the line (and thus resolution is a function of both the DAC in the display device in the case of systems that generate a digital signal and then convert it to analog for display, and the hardware insid…
Years ago I had an LG 32" wide-screen CRT TV. I chose that model because it had a VGA port. It advertised a resolution of 640x480. I was thrilled when my computer let me choose a resolution of 848x480, and it worked perfectly. Back in those days, the web was usable at that resolution.
It still basically should be, so long as well-designed sites give you the "small screen"/mobile layout.
Even apart from that, a lot of laptops still have 1280x800 as the default resolution, and that's only double the width of 640x480. Honestly, I'd actually be more worried about OS and browser chrome eating up the space than websites themselves being unusable.
Re: How does a screen work?
#47Earlier quoted context omitted.
Years ago I had an LG 32" wide-screen CRT TV. I chose that model because it had a VGA port. It advertised a resolution of 640x480. I was thrilled when my computer let me choose a resolution of 848x480, and it worked perfectly. Back in those days, the web was usable at that resolution.
It still basically should be, so long as well-designed sites give you the "small screen"/mobile layout. Even apart from that, a lot of laptops still have 1280x800 as the default resolution, and that's only double the width of 640x480. Honestly, I'd actually be more worried about OS and browser chrome eating up the space than websites themselves being unusable.
The 480 height is the bigger issue.
Try browsing on your phone in landscape mode.
Re: How does a screen work?
#48Earlier quoted context omitted.
Years ago I had an LG 32" wide-screen CRT TV. I chose that model because it had a VGA port. It advertised a resolution of 640x480. I was thrilled when my computer let me choose a resolution of 848x480, and it worked perfectly. Back in those days, the web was usable at that resolution.
It still basically should be, so long as well-designed sites give you the "small screen"/mobile layout. Even apart from that, a lot of laptops still have 1280x800 as the default resolution, and that's only double the width of 640x480. Honestly, I'd actually be more worried about OS and browser chrome eating up the space than websites themselves being unusable.
> "It still basically should be, so long as well-designed sites..."
I believe that their point wasn't that "the web" has intrinsically changed, it was that too many sites are not well designed in this respect.
edit: they actually replied just before me and it seems that wasn't their point, but it would be my point (though I personally don't care about being able to use such a low resolution).
Re: How does a screen work?
#49CRT displays are one of those analog technologies that are arguably much cooler than their digital successors. Think – a literan raygun, a particle accelerator, inside your monitor, creating the image you're looking at.
Active matrix flat panels felt like incredibly cool technology when they became available in the 1990s. Each individual pixel is driven by a transistor and capacitor that actively maintain the pixel state? Insane manufacturing magic. Dead pixels used to be a big problem with LCD displays. Haven’t thought about that in at least twenty years.
True – but on the other hand, it was "only" a few million elements, and very large ones, compared to, say, the DRAM chips of the time. Monitors certainly make the engineering feat more tangible, though!
Re: How does a screen work?
#50Very cool looking website. Looking forward to the quality content