Elven_Star said:
Shouldn't CRTs with smaller footprint be somehow possible with today's technology?
It's not something that could really be "fixed" with the traditional CRT design.
The issue is that its electron beam is emitted from a central point at the back of the display, so the thinner you make the TV, the sharper the angle is into the corners of the screen.
A sharper angle means your corners are going to be out of focus relative to the center of the display, and you'll get awful convergence as well (color fringing).
This was already an issue when they moved to flat-faced CRTs, before trying to make them thinner (see: Samsung Slimfit CRTs and their poor reputation).
CRT manufacturing is unlikely to happen unless some billionaire decides to make it their pet project.
All of the factories producing high-end displays were shut down/retooled 15+ years ago. The hardware to manufacture them doesn't really exist any more, and most of the engineers are likely to be retired.
There were also (somewhat overstated) environmental concerns, which would have to be worked around if a new CRT were to be produced today.
It just doesn't seem feasible for a niche enthusiast product. Even many retro gaming enthusiasts probably wouldn't buy a CRT if they were being produced again, due to the size/weight etc.
EvilBoris said:
That's motion resolution , which is a loss of detail in motion.
That's not the psychological effect of motion perception from low framerates, which is usually the concern - hence the parts about framerates variances being just as noticeable on a CRT, infact more noticeable because of the newer instant response of a CRT compared to some modern displays
As with all display technology, motion handling, and perception discussions… it's complicated.
The short answer is that lower image persistence looks smoother, on top of giving you better motion clarity.
There are two main factors in how a display will present motion:
- Response times.
- Image persistence.
Response times are how quick a display's pixels are at changing from one frame to another.
Image persistence is how long a display holds each frame on-screen.
- LCD: Slow response times, High image persistence.
- OLED: Fast response times, High image persistence.
- CRT: Fast response times, Low image persistence.
If we alternate bright and dark frames on a display, the characteristics of each might look something like this:
With a 60 FPS game, an LCD or OLED are both going to hold each frame on-screen for ~17ms.
But the LCD has slow rise and fall times (plus some overshoot), while the OLED is nearly instantaneous.
Those slow rise/fall times are why LCD tends to smear frames in motion, but also why some people might think it is "smoother" than OLED.
No matter the source frame rate, a CRT is always going to flash the image on-screen for <2ms.
CRTs cannot hold an image on-screen like flat-panel TVs do - they have to draw it again every refresh, even if it has not changed - which is why they flicker.
CRTs typically have very fast rise times, but slower fall times - which helps make the flicker less harsh for any given refresh rate/image persistence.
Black Frame Insertion cuts down the hold times of an LCD or OLED display, and causes it to flicker.
With an LG C1 OLED, the highest level of BFI (Motion Pro) will drop hold times to ~8ms at 60Hz and 4ms at 120Hz.
The CX was a bit different, reducing the hold times to 4ms at both 60Hz and 120Hz (at the cost of being half as bright at 60Hz).
But even though the hold time might be twice as long (or more) compared to a CRT, the flicker is very harsh on an OLED because of the near-instant rise/fall of the response times giving it a square-wave response, rather than an exponential response like the CRT.
And that carries over to 30 FPS gaming.
I don't find that 30 FPS is smoother on LCD compared to OLED, it's just harsher on the OLED because of those response times - particularly in bright, high-contrast scenes.
Even so, I find that the higher contrast and lack of image smearing helps reduce motion sickness for me vs. an LCD.
CRTs at 30 FPS are a whole other story that I don't want to get into, but let's just say that they have their own issues (very sharp motion, but with double-images for 30 FPS at 60Hz).
Dr. Zoidberg said:
The smaller size of the CRT screen likely helps a great deal as well. A choppy framerate is even worse on a large screen that fills more of your FOV.
This is definitely a factor. Image size and brightness have a huge impact on how smooth we perceive motion to be.
I suspect it also plays a role for people that went from a mid-size, mid-range LCD, to a much bigger OLED and find lower frame rates less tolerable.
100mega said:
Wow, I've never really considered this. Very interesting! Also I sure wish we could have seen what SED TVs could have turned into.
SED televisions were fixed-pixel displays that used PWM-driving similar to Plasma TVs, so you could really just think of them as an advanced plasma tv with higher-contrast and faster response times.
They might have been great if they were actually released at that time, but did not have the characteristics of a "flat-panel CRT" that many people dream of.
