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I do not understand at all what this is talking about or why. Is it some elaborate joke? Don't visual effects people go to lots of effort to add motion blur? W

I do not understand at all what this is talking about or why. Is it some elaborate joke? Don't visual effects people go to lots of effort to add motion blur? Why would you want to remove it? Why are they trying to simulate old CRT displays? Can someone explain what this is about?

martini333 2y ago
Why exactly do you think motion blur is added?
fishermanbill 2y ago
Yeah they are two different effects. Theres motion blur on individual objects that you want (as human eyes see/have) then there is full screen motion blur that is due to the display technology (lcd,oled etc) that you dont want (as human eyes dont see/have). CRTs dont have this motion blur as the screen is blank most of the time - see slo mo guys on youtube for crt displays.
Springtime 2y ago
This is about improving motion clarity, so each displayed frame of moving content looks crisp rather than having blur (something that monitors can struggle with even at high refresh rates / high Hz). Most good monitor reviews of high Hz displays (eg: 120Hz+) take fast photographs of moving objects (typically from Blur Busters' 'Test UFO' web page) to demonstrate how good or poorly a monitor handles fast moving content. One technique of significantly improving motion clarity is inserting frames of pure black in the display output (aka BFI, black frame insertion). A downside is some are sensitive to this where it causes eyestrain. This CRT beam simulating shader is said to be similarly effective to BFI at improving motion clarity but with the benefit of reducing eyestrain. However from what I understand the current version is limited to simulating a lower Hz display and requires a higher Hz monitor. All this is distinct from the kind of in-media motion blur that can be enabled in games or seen in recorded video. It's instead about the monitor not being able to render fast moving content clearly enough which leads to non-crisp output frames.
- stevage 2y ago
  Thank you, that's a really great explanation.
- noduerme 2y ago
  What is the method used on newer TVs that attempts to double the framerate / interpolate frames / make everything shot on film look like an overlit soap opera? I find it impossible to watch; it destroys the lighting and the performances. My recollection of CRT TVs was that they had a lot of blur, both motion and spatial, and that was kind of what made them feel warmer and more analog / less overly crispy.
  - Springtime 2y ago
    That's typically called 'motion smoothing' and yeah that's trying to interpolate frames to manipulate lower framerate video (like 24FPS) into higher framerates in an attempt to make scenes like panning shots 'smoother' at the expense of a soap opera feel and interpolation artifacting. Whereas what Blur Busters (and similar enthusiasts) are focused on is how accurately frames are (perceptibly) displayed on the screen, so ideally each input frame is perfectly presented without any interference from prior frames (due to limits of panels in keeping up with changing the pixels from one frame to another, very rapidly, causing blurring). The ultimate goal, in a perfect scenario, is for input from say a video game running at 60 frames per second to have each frame perfectly rendered like individual screenshot stills, one after the other. In reality for most monitors displaying such content there's not enough distinct separation between frames, leading fast changing pixel content (like objects moving) to blend into each other, causing blurring at the monitor level. The BFI technique, by inserting alternating black frames in the output, mitigates the inter-frame blending issues since instead of the prior frame being various colors (ie: of the prior input frame) it's starting from pure black which dramatically reduces frame blending artifacts and perceptibly makes the motion clarity more distinct.
    - CuriousSkeptic 2y ago
      It’s not that the frames blend in the screen. Screens are perfectly capable of switching the pixels fast enough. It’s rather that each frame is displayed for to long. In a CRT the “pixels” start to fade immediately leaving the full screen mostly dark as the beam sweeps over the screen. It never shows a full frame. One could say that modern screens are more like slide shows, while BFI tries to make them more like stroboscopes. The blurring effect is more pronounced ate low refresh rates, its just that BFI requires at least 120hz to male sense at all.
7734128 2y ago
Because I hate it.
haunter 2y ago
First thing I turn off in every single game is motion blur. It’s only useful in racing sims to have more sense of speed but that’s also a personal taste. Motion blur made a bit more sense on the 30fps Xbox 360 and PS3 games.
cubefox 2y ago
Our eyes are constantly and mostly unconsciously tracking moving objects in our field of view in order to keep them still relative to our eyes. It's called Smooth pursuit: https://en.wikipedia.org/wiki/Smooth_pursuit https://en.wikipedia.org/wiki/Smooth_pursuit This is because our retina has a very low "refresh rate", which means things can easily blur together. Smooth pursuit prevents that. However, modern sample-and-hold displays like LCD and OLED work against Smooth pursuit. If you watch anything moving on a screen (including "still" objects moving on screen due to camera movement), your eye will automatically track those objects if they are momentarily the focus of attention, which should make them be still relative to your eyes and thus appear sharp. However, since the tracked object is being still relative to your eyes and the individual frames on screen are being still relative to your screen, the frames move (are not being still) relative to your eyes. Which means they appear blurry during smooth pursuit, when in reality they should be perfectly sharp. For example, your eyes track a sign that moves on the screen due to camera movement. Say it moves 10 pixels per frame horizontally. This means you will see a 10 pixel wide horizontal blur on this sign. Which could make it unreadable. In reality (without screen with a real sign) the sign would appear perfectly clear. On CRT screens this doesn't happen (to the same extent) because the frame is not displayed for the entire frame time (e.g. 1/60th of a second) but much shorter. The CRT just very quickly flashes the frames and is dark in between. Strobing/flickering basically. So if the tracked object moves 10 pixels per frame, the frame might only be (say) visible for 1/5th of that frame time, which means it moves only 2 pixel while the frame is actually on screen. So you get only 2 pixel blur, which is much less. Of course at 60 FPS you might instead get some degree of perceptible flicker (computer CRTs therefore often ran higher than 60) and in general the overall achievable screen brightness will be darker, since the screen is black most of each frame time. CRTs had a low maximum brightness. But they had very little of the "persistence blur" which plagues sample-and-hold screens like OLED and LCD. The motion blur intentionally introduced by video games is there to make moving objects appear smoother that are not tracked by our eyes. In that case motion blur is natural (since smooth pursuit doesn't try to remove it). So some forms of motion blur are undesirable and others are desirable. The optimal solution would be to run games (and videos content in general) at an extremely high frame rate (like 1000 FPS) which would introduce natural perceptible motion blur where it naturally occurs and remove it where it doesn't naturally occur (during smooth pursuit). But obviously that would be computationally an extremely inefficient way to render games. By the way, if you have a screen with 120+ Hz you can test the above via this black frame insertion demo, which emulates how CRTs work: https://testufo.com/blackframes https://testufo.com/blackframes On my 120 Hz OLED screen, the 40 FPS (1 frame + 2 black frames) UFO looks as clear as the native 120 Hz UFO. A real 60 or even 80 Hz CRT screen would be even better in terms of motion clarity. Perhaps better than a 240 or even 480 Hz OLED.

martini333 2y ago

Why exactly do you think motion blur is added?

fishermanbill 2y ago

Yeah they are two different effects. Theres motion blur on individual objects that you want (as human eyes see/have) then there is full screen motion blur that is due to the display technology (lcd,oled etc) that you dont want (as human eyes dont see/have). CRTs dont have this motion blur as the screen is blank most of the time - see slo mo guys on youtube for crt displays.

Springtime 2y ago

This is about improving motion clarity, so each displayed frame of moving content looks crisp rather than having blur (something that monitors can struggle with even at high refresh rates / high Hz). Most good monitor reviews of high Hz displays (eg: 120Hz+) take fast photographs of moving objects (typically from Blur Busters' 'Test UFO' web page) to demonstrate how good or poorly a monitor handles fast moving content. One technique of significantly improving motion clarity is inserting frames of pure black in the display output (aka BFI, black frame insertion). A downside is some are sensitive to this where it causes eyestrain. This CRT beam simulating shader is said to be similarly effective to BFI at improving motion clarity but with the benefit of reducing eyestrain. However from what I understand the current version is limited to simulating a lower Hz display and requires a higher Hz monitor. All this is distinct from the kind of in-media motion blur that can be enabled in games or seen in recorded video. It's instead about the monitor not being able to render fast moving content clearly enough which leads to non-crisp output frames.

stevage 2y ago
Thank you, that's a really great explanation.
noduerme 2y ago
What is the method used on newer TVs that attempts to double the framerate / interpolate frames / make everything shot on film look like an overlit soap opera? I find it impossible to watch; it destroys the lighting and the performances. My recollection of CRT TVs was that they had a lot of blur, both motion and spatial, and that was kind of what made them feel warmer and more analog / less overly crispy.
- Springtime 2y ago
  That's typically called 'motion smoothing' and yeah that's trying to interpolate frames to manipulate lower framerate video (like 24FPS) into higher framerates in an attempt to make scenes like panning shots 'smoother' at the expense of a soap opera feel and interpolation artifacting. Whereas what Blur Busters (and similar enthusiasts) are focused on is how accurately frames are (perceptibly) displayed on the screen, so ideally each input frame is perfectly presented without any interference from prior frames (due to limits of panels in keeping up with changing the pixels from one frame to another, very rapidly, causing blurring). The ultimate goal, in a perfect scenario, is for input from say a video game running at 60 frames per second to have each frame perfectly rendered like individual screenshot stills, one after the other. In reality for most monitors displaying such content there's not enough distinct separation between frames, leading fast changing pixel content (like objects moving) to blend into each other, causing blurring at the monitor level. The BFI technique, by inserting alternating black frames in the output, mitigates the inter-frame blending issues since instead of the prior frame being various colors (ie: of the prior input frame) it's starting from pure black which dramatically reduces frame blending artifacts and perceptibly makes the motion clarity more distinct.
  - CuriousSkeptic 2y ago
    It’s not that the frames blend in the screen. Screens are perfectly capable of switching the pixels fast enough. It’s rather that each frame is displayed for to long. In a CRT the “pixels” start to fade immediately leaving the full screen mostly dark as the beam sweeps over the screen. It never shows a full frame. One could say that modern screens are more like slide shows, while BFI tries to make them more like stroboscopes. The blurring effect is more pronounced ate low refresh rates, its just that BFI requires at least 120hz to male sense at all.

7734128 2y ago

Because I hate it.

haunter 2y ago

First thing I turn off in every single game is motion blur. It’s only useful in racing sims to have more sense of speed but that’s also a personal taste. Motion blur made a bit more sense on the 30fps Xbox 360 and PS3 games.

cubefox 2y ago

Our eyes are constantly and mostly unconsciously tracking moving objects in our field of view in order to keep them still relative to our eyes. It's called Smooth pursuit: https://en.wikipedia.org/wiki/Smooth_pursuit https://en.wikipedia.org/wiki/Smooth_pursuit This is because our retina has a very low "refresh rate", which means things can easily blur together. Smooth pursuit prevents that. However, modern sample-and-hold displays like LCD and OLED work against Smooth pursuit. If you watch anything moving on a screen (including "still" objects moving on screen due to camera movement), your eye will automatically track those objects if they are momentarily the focus of attention, which should make them be still relative to your eyes and thus appear sharp. However, since the tracked object is being still relative to your eyes and the individual frames on screen are being still relative to your screen, the frames move (are not being still) relative to your eyes. Which means they appear blurry during smooth pursuit, when in reality they should be perfectly sharp. For example, your eyes track a sign that moves on the screen due to camera movement. Say it moves 10 pixels per frame horizontally. This means you will see a 10 pixel wide horizontal blur on this sign. Which could make it unreadable. In reality (without screen with a real sign) the sign would appear perfectly clear. On CRT screens this doesn't happen (to the same extent) because the frame is not displayed for the entire frame time (e.g. 1/60th of a second) but much shorter. The CRT just very quickly flashes the frames and is dark in between. Strobing/flickering basically. So if the tracked object moves 10 pixels per frame, the frame might only be (say) visible for 1/5th of that frame time, which means it moves only 2 pixel while the frame is actually on screen. So you get only 2 pixel blur, which is much less. Of course at 60 FPS you might instead get some degree of perceptible flicker (computer CRTs therefore often ran higher than 60) and in general the overall achievable screen brightness will be darker, since the screen is black most of each frame time. CRTs had a low maximum brightness. But they had very little of the "persistence blur" which plagues sample-and-hold screens like OLED and LCD. The motion blur intentionally introduced by video games is there to make moving objects appear smoother that are not tracked by our eyes. In that case motion blur is natural (since smooth pursuit doesn't try to remove it). So some forms of motion blur are undesirable and others are desirable. The optimal solution would be to run games (and videos content in general) at an extremely high frame rate (like 1000 FPS) which would introduce natural perceptible motion blur where it naturally occurs and remove it where it doesn't naturally occur (during smooth pursuit). But obviously that would be computationally an extremely inefficient way to render games. By the way, if you have a screen with 120+ Hz you can test the above via this black frame insertion demo, which emulates how CRTs work: https://testufo.com/blackframes https://testufo.com/blackframes On my 120 Hz OLED screen, the 40 FPS (1 frame + 2 black frames) UFO looks as clear as the native 120 Hz UFO. A real 60 or even 80 Hz CRT screen would be even better in terms of motion clarity. Perhaps better than a 240 or even 480 Hz OLED.