General > General Technical Chat
Just because technology can do something, doent meant its always right
2N3055:
--- Quote from: Simon on June 20, 2022, 09:05:48 pm ---Don't know what you mean by focal plane, yes we see with the centre of our eyes the most, I think from memory it is something like a 1.5 degree angle that has most of the ability with the rest being peripheral vision or pieced together and yes all of the screen needs to be of a resolution that the centre of the eye cannot see the pixels but what is that resolution? (angular resolution will do as it will be agnostic to the screen size/distance)
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https://www.eevblog.com/forum/chat/just-because-technology-can-do-something-doent-meant-its-always-right/msg4249858/#msg4249858
That is actually measured by scientists...
bd139:
--- Quote from: 2N3055 on June 20, 2022, 09:11:09 pm ---
--- Quote from: Simon on June 20, 2022, 09:05:48 pm ---Don't know what you mean by focal plane, yes we see with the centre of our eyes the most, I think from memory it is something like a 1.5 degree angle that has most of the ability with the rest being peripheral vision or pieced together and yes all of the screen needs to be of a resolution that the centre of the eye cannot see the pixels but what is that resolution? (angular resolution will do as it will be agnostic to the screen size/distance)
--- End quote ---
https://www.eevblog.com/forum/chat/just-because-technology-can-do-something-doent-meant-its-always-right/msg4249858/#msg4249858
That is actually measured by scientists...
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No they're wrong. Because at greater than 1m I can clearly tell the difference between the 4k and a 5k 27" screen at 157dpi and 218dpi which I sit in front of every day.
If I open the full London connections tube map to 1/4 of each screen in a PDF, I can read the station names on the 5k but not on the 4k. The information isn't even there on the 4k. On a 1440p screen I'd probably have to have it full screen.
Also there's no citation or conditions for your information. Perhaps that's an AVERAGE across the entire eye. Within the focal centre there might be 50x the resolution of 0.3mm and that's what is important.
Edit: here's a 14.2" 3024x1964 screenshot with the tube map at 254ppi which is 60-70cm away from me.
I can read the station names fine! (I have above average eyesight for ref)
tom66:
Anyone who claims they can resolve anything better than 4K should try one of these test patterns that I just made in Python. If displayed at 1:1 at the normal viewing distance of your monitor, you should be able to see pixels if a higher resolution would benefit you. If you can only see grey, then further resolution will provide no advantage. I can only *just* see the pixel pattern, but it's mostly grey to me, so at best I would estimate I *might* benefit from 5K, but beyond would be pointless.
Interestingly enough using the checkerboard pattern on my Samsung monitor results in a green tint to the image. I suspect this is caused by the excessive current that this pattern draws. I can see the rows around this pattern are darker, and they get darker and the pattern gets greener the more column space it covers. It shows one limitation of LCD technology. A high number of transitions implies large capacitive drive current (as the column drivers will be alternating to drive each pixel, and the row drivers will have to conduct this current. The panel is scanned vertically, so each column driver will have to swing between Vcom and Vdd or GND depending on the subframe.) I suppose this means in theory there are some images, which if displayed for some time, could shorten the life of a panel, as the chip-on-flex drivers are usually non-replaceable.
I recall owning a Panasonic plasma TV that would detect this specific pattern and begin to dim the panel after about 5 seconds to prevent the address drivers from overheating: those chips had to swing from 75V to 0V and back again at a rate of several MHz, and a typical 1920-wide panel would feature 5760 channels on custom chip-on-flex drivers with minature heatsinks. Now that's power semiconductor design :) (It's one of these chips that killed Dave's old Panasonic PDP, but it must be said that failures are rare!)
bd139:
It's more complicated than test patterns. The representation of text and how the eye perceives it is what you are paying for.
Compare an inkjet printout to a decent laser printer printout and you'll see what I mean.
tom66:
--- Quote from: bd139 on June 20, 2022, 09:22:54 pm ---It's more complicated than test patterns. The representation of text and how the eye perceives it is what you are paying for.
Compare an inkjet printout to a decent laser printer printout and you'll see what I mean.
--- End quote ---
I disagree. If you can't see the pixels then fundamentally it doesn't matter what your brain does with the information, everything beyond that is interpolation on data that is there at any resolution beyond the maximum fidelity of your optic system.
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