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Solid overview of applied color theory for video, so worth watching. As to what was to be debunked, the presentation not only fails to set out a thesis in the

by _wire_ 1y ago

Solid overview of applied color theory for video, so worth watching. As to what was to be debunked, the presentation not only fails to set out a thesis in the introduction, it doesn't even beg a question, so you've got to watch hours to get to the point: SDR and HDR are two measurement systems which when correctly used for most cases (legacy and conventional content) must produce the visual result. The increased fidelity of HDR makes it possible to expand the sensory response and achieve some very realistic new looks that were impossible with SDR, but the significance and value of any look is still up to the creativity of the photographer. This point could be more easily conveyed by this presentation if the author explained in the history of reproduction technology, human visual adaptation exposes a moment by moment contrast window of about 100:1, which is constantly adjusting across time based on average luminance to create an much larger window of perception of billions:1(+) that allows us to operate under the luminance conditions on earth. But until recently, we haven't expected electronic display media to be used in every condition on earth and even if it can work, you don't pick everywhere as your reference environment for system alignment. (+)Regarding difference between numbers such as 100 or billions, don't let your common sense about big or small values phase your thinking about differences: perception is logarithmic; it's the degree of ratios that matter more than the absolute magnitude of the numbers. As a famous acoustics engineer (Paul Klipsch) said about where to focus design optimization of response traits of reproduction systems: "If you can't double it or halve it, don't worry about it."

strogonoff 1y ago
Regardless of whether it is HDR or SDR, when processing raw data for display spaces one must throw out 90%+ of information of what was captured by the sensor (which is often a small amount of what was available at the scene already). There can simply be no objectivity, it is always about what you saw and what you want others to see, an inherently creative task.
- ttoinou 1y ago
  90% really ? What color information get ejected exactly ? For the sensor part are you talking about the fact that the photosites don't cover all the surface ? Or that we only capture a short band of wavelength ? Or that the lens only focuses rays unto specific exact points and make the rest blurry and we loose 3D ?
  - adgjlsfhk1 1y ago
    Presumably they're referring to the fact that most cameras capture ~12-14 bits of brightness vs the 8 that (non-hdr) displays show.
    - ttoinou 1y ago
      Oh that's normal then. There are mandatory steps of dynamic range reduction in the video editing / color grading pipeline (like a compressor in audio production). So the whole information is not lost but the precision / details can be yes. But that's a weird definition, there are so many photons in daylight capture that you could easily say we really need minimum 21 bits per channel minimum (light intensity of sun / light intensity of moon)
      - bdavbdav 1y ago
        But that’s not seen at the sensor - at least not at once - look at the sun and then look immediately at the dark sky moon (if it were possible) - the only reason you get the detail on the moon is the aperture in front. You couldn’t see the same detail if they were next to each other. The precision is the most dark in the scene next to the most bright, as opposed to the most dark possible next to the most bright. That’s the difference.
        ttoinou 1y ago
        Hum I can look at a moon croissant and the sun at the same time
        bdavbdav 1y ago
        Do you not find it takes your eyes time to adjust to different brightness levels? There’s a good reason boats use red lights inside at night.
      - strogonoff 1y ago
        > So the whole information is not lost but the precision / details can be yes. That does not seem a meaningful statement. Information, and by far most of it, is necessarily discarded. The creative task of the photographer is in deciding what is to be discarded (both at shooting time and at editing time) and shaping the remaining data to make the optimal use of the available display space. Various ways of competing dynamic range is often part of this process. > like a compressor in audio production Audio is a decent analogy and an illustration of why it is a subjective and creative process. You don’t want to just naively compress everything into a wall of illegible sound, you want to make some things pop at the expense of other things, which is a similar task in photography. Like with photography, you must lose a lot of information at it, because if you preserve all the finest details no one would be able to hear much in real-life circumstances.
dperfect 1y ago
It's hard to boil it down to a simple thesis because the problem is complicated. He admits this in the presentation and points to it being part of the problem itself; there are so many technical details that have been met with marketing confusion and misunderstanding that it's almost impossible to adequately explain the problem in a concise way. Here's my takeaway: - It was clearly a mistake to define HDR transfer functions using absolute luminance values. That mistake has created a cascade of additional problems - HDR is not what it was marketed to be: it's not superior in many of the ways people think it is, and in some ways (like efficiency) it's actually worse than SDR - The fundamental problems with HDR formats have resulted in more problems: proprietary formats like Dolby Vision attempting to patch over some of the issues (while being more closed and expensive, yet failing to fully solve the problem), consumer devices that are forced to render things worse than they might be in SDR due to the fact that it's literally impossible to implement the spec 100% (they have to make assumptions that can be very wrong), endless issues with format conversions leading to inaccurate color representation and/or color banding, and lower quality streaming at given bit rates due to HDR's reliance on higher bit depths to achieve the same tonal gradation as SDR - Not only is this a problem for content delivery, but it's also challenging in the content creation phase as filmmakers and studios sometimes misunderstand the technology, changing their process for HDR in a way that makes the situation worse Being somewhat of a film nerd myself and dealing with a lot of this first-hand, I completely agree with the overall sentiment and really hope it can get sorted out in the future with a more pragmatic solution that gives filmmakers the freedom to use modern displays more effectively, while not pretending that they should have control over things like the absolute brightness of a person's TV (when they have no idea what environment it might be in).
- adrian_b 1y ago
  While HDR has the problems described by you, in practice, whenever possible, I choose the HDR version of a movie over its SDR version. The reason is not HDR itself, but the fact that the HDR movies normally use the BT.2020 color space, while the SDR movies normally use the BT.709 color space. The color spaces based on the limitations of the first color CRT tubes, which are no longer relevant today, i.e. sRGB, BT.709 and the like, are really unacceptable from my point of view, because they cannot reproduce many of the more saturated colors in the red-orange region, which are frequently encountered in nature and in manufactured objects, and which are also located in a region of the color space where human vision is most sensitive. While no cheap monitor can reproduce the full BT.2020, many cheap monitors can reproduce the full DCI-P3 color space, which provides adequate improvements in the red-orange corner over sRGB/BT.709.

by _wire_ 1y ago

strogonoff 1y ago

Regardless of whether it is HDR or SDR, when processing raw data for display spaces one must throw out 90%+ of information of what was captured by the sensor (which is often a small amount of what was available at the scene already). There can simply be no objectivity, it is always about what you saw and what you want others to see, an inherently creative task.

ttoinou 1y ago
90% really ? What color information get ejected exactly ? For the sensor part are you talking about the fact that the photosites don't cover all the surface ? Or that we only capture a short band of wavelength ? Or that the lens only focuses rays unto specific exact points and make the rest blurry and we loose 3D ?
- adgjlsfhk1 1y ago
  Presumably they're referring to the fact that most cameras capture ~12-14 bits of brightness vs the 8 that (non-hdr) displays show.
  - ttoinou 1y ago
    Oh that's normal then. There are mandatory steps of dynamic range reduction in the video editing / color grading pipeline (like a compressor in audio production). So the whole information is not lost but the precision / details can be yes. But that's a weird definition, there are so many photons in daylight capture that you could easily say we really need minimum 21 bits per channel minimum (light intensity of sun / light intensity of moon)
    - bdavbdav 1y ago
      But that’s not seen at the sensor - at least not at once - look at the sun and then look immediately at the dark sky moon (if it were possible) - the only reason you get the detail on the moon is the aperture in front. You couldn’t see the same detail if they were next to each other. The precision is the most dark in the scene next to the most bright, as opposed to the most dark possible next to the most bright. That’s the difference.
      - ttoinou 1y ago
        Hum I can look at a moon croissant and the sun at the same time
        bdavbdav 1y ago
        Do you not find it takes your eyes time to adjust to different brightness levels? There’s a good reason boats use red lights inside at night.
    - strogonoff 1y ago
      > So the whole information is not lost but the precision / details can be yes. That does not seem a meaningful statement. Information, and by far most of it, is necessarily discarded. The creative task of the photographer is in deciding what is to be discarded (both at shooting time and at editing time) and shaping the remaining data to make the optimal use of the available display space. Various ways of competing dynamic range is often part of this process. > like a compressor in audio production Audio is a decent analogy and an illustration of why it is a subjective and creative process. You don’t want to just naively compress everything into a wall of illegible sound, you want to make some things pop at the expense of other things, which is a similar task in photography. Like with photography, you must lose a lot of information at it, because if you preserve all the finest details no one would be able to hear much in real-life circumstances.

dperfect 1y ago

It's hard to boil it down to a simple thesis because the problem is complicated. He admits this in the presentation and points to it being part of the problem itself; there are so many technical details that have been met with marketing confusion and misunderstanding that it's almost impossible to adequately explain the problem in a concise way. Here's my takeaway: - It was clearly a mistake to define HDR transfer functions using absolute luminance values. That mistake has created a cascade of additional problems - HDR is not what it was marketed to be: it's not superior in many of the ways people think it is, and in some ways (like efficiency) it's actually worse than SDR - The fundamental problems with HDR formats have resulted in more problems: proprietary formats like Dolby Vision attempting to patch over some of the issues (while being more closed and expensive, yet failing to fully solve the problem), consumer devices that are forced to render things worse than they might be in SDR due to the fact that it's literally impossible to implement the spec 100% (they have to make assumptions that can be very wrong), endless issues with format conversions leading to inaccurate color representation and/or color banding, and lower quality streaming at given bit rates due to HDR's reliance on higher bit depths to achieve the same tonal gradation as SDR - Not only is this a problem for content delivery, but it's also challenging in the content creation phase as filmmakers and studios sometimes misunderstand the technology, changing their process for HDR in a way that makes the situation worse Being somewhat of a film nerd myself and dealing with a lot of this first-hand, I completely agree with the overall sentiment and really hope it can get sorted out in the future with a more pragmatic solution that gives filmmakers the freedom to use modern displays more effectively, while not pretending that they should have control over things like the absolute brightness of a person's TV (when they have no idea what environment it might be in).

adrian_b 1y ago
While HDR has the problems described by you, in practice, whenever possible, I choose the HDR version of a movie over its SDR version. The reason is not HDR itself, but the fact that the HDR movies normally use the BT.2020 color space, while the SDR movies normally use the BT.709 color space. The color spaces based on the limitations of the first color CRT tubes, which are no longer relevant today, i.e. sRGB, BT.709 and the like, are really unacceptable from my point of view, because they cannot reproduce many of the more saturated colors in the red-orange region, which are frequently encountered in nature and in manufactured objects, and which are also located in a region of the color space where human vision is most sensitive. While no cheap monitor can reproduce the full BT.2020, many cheap monitors can reproduce the full DCI-P3 color space, which provides adequate improvements in the red-orange corner over sRGB/BT.709.