Thread: Komodo 12.2 stops of dynamic range in CineD test.

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  1. #71  
    Quote Originally Posted by Alex Lubensky View Post
    I suppose rating a camera to a 60% in LOG is wrong as a starting point. It’s 60% in REC 709 profiles, be it RG RC4, IPP2 BT1886 etc.
    Indeed. Some arbitrary decisions are easy to justify. Others...not so much.
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  2. #72  
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    Quote Originally Posted by Björn Benckert View Post
    Downsampling helps latitude, so does noise reduction, explain why such tools should not be used? Or what parameters do you consider such that can be used to improve the image, only those that are added destructively in camera?
    Don't get me wrong, NR should certainly be used when needed, but not relied on in order to merely achieve (or worse, artificially inflate) the advertised DR numbers of a digital cinema camera's raw capture. Similar to those monochrome-ish highlight recovered stops.

    Your two examples - downscaling vs NR - is a good one; both reduce perceived noise, but downscaling 1.) doesn't really require additional render time and more importantly 2.) is non-destructive, while NR to dig stops out of the noise floor requires 4x the render time and *is* destructive... Those are pretty big, objectively negative, caveats to relying on NR. And not only is the amount of acceptable NR subjective, but it can be applied to every camera in order to increase their shadow DR numbers, not just Komodo. So it adds huge (and subjective) variables to an already contentious comparison.

    Personally, I would think those stops (both the NR recovered lows *and* monochrome-ish recovered highs) should be considered the "+" in advertised numbers, not part of the whole/RGB/full stops... but that's just me (and Arri... and I think BMD... butt I digress.)

    Quote Originally Posted by Alex Lubensky View Post
    I suppose rating a camera to a 60% in LOG is wrong as a starting point. It’s 60% in REC 709 profiles, be it RG RC4, IPP2 BT1886 etc.
    True. But I was under the impression that all the cameras in this comparison were done the same way, so the over/under exposure recovery comparison would still hold (which is why I've referenced the Komodo +1 vs P6k +4 on that skintone highlight). Conversely, regardless of where RED's "log 60%" compares to it's "709/normalized 60%", it'd still be a trade-off of either noise being introduced earlier or highlights clipped sooner (I thought that's why Gunther was saying it's just a point or reference). Basically taking a block from the bottom and putting it on top.

    ...Though, maybe it'd give a more even over/under at a more palatable ISO. e.g. ISO1600 instead of 3200, which would be a much nicer/cleaner starting point (maybe enough to skip that NR step!)

    Quote Originally Posted by Brian Roberts View Post
    So, if it is true that Komodo has the upper two highlight stops reconstructed to grayscale, can we also assume that these stops are included in the goal post readings?
    That's an important question (since, as you mentioned, if we know it is, we can just protect the highlights more to compensate). Since Komodo is the first time the HR recovery has been done in-camera, I would think that means it counts them in the goal post... but the stop lights would be popping before that, so you'd know... Also there's Jarred's new fandangled channel clipping exposure tool, too.

    Have they put GioScope in Komodo yet? If so, it'd be easy enough to treat chip 14 as the last stop (instead of 16).
    Last edited by Mike P.; 01-24-2021 at 10:23 AM.
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  3. #73  
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    You all are aware he updated and corrected the article about 6 days ago? Interesting quote in there from Graeme.
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  4. #74  
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    Quote Originally Posted by Jon Dishler View Post
    You all are aware he updated and corrected the article about 6 days ago? Interesting quote in there from Graeme.
    LOL. Yeah we know, but the results didn't change, so the concerns/questions (about those top two reconstructed-stops and comparatively poor highlight performance because of them) remain.

    Similarly, questions about metering (to protect), exposing tricks (to compensate), and how Dragon/Helium/Gemini/Monstro/others HR compare are also being discussed.
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  5. #75  
    Quote Originally Posted by Mike P. View Post
    Don't get me wrong, NR should certainly be used when needed, but not relied on in order to merely achieve (or worse, artificially inflate) the advertised DR numbers of a digital cinema camera's raw capture. Similar to those monochrome-ish highlight recovered stops.
    You might have missed this the first time around:

    Quote Originally Posted by Michael Tiemann View Post
    On the subject of noise reduction, I think it's perfectly reasonable to report numbers as long as the NR type and parameters are reported. 1-frame TNR in Resolve does a great job reducing shadow noise in RAW files. Not so much for mpeg-encoded files with macro blocking. Similarly, RED's Chroma Noise Reduction also works very well at calming things down and increasing SNR.

    Almost all astrophotography photos use extensive NR, and it would be almost meaningless to try to evaluate the merits of a given imaging platform without consideration of how that platform supports (or prevents) the application of NR techniques essential to the craft.

    Of course we don't expect testing orgs to run through every NR technique with every possible parameter setting that forces us to sift through 50,000 results to find the one that's most meaningful to us. But I don't think it's wrong to acknowledge when a very straightforward approach leads to a significant change in final results.
    You continue:

    Your two examples - downscaling vs NR - is a good one; both reduce perceived noise, but downscaling 1.) doesn't really require additional render time and more importantly 2.) is non-destructive, while NR to dig stops out of the noise floor requires 4x the render time and *is* destructive... Those are pretty big, objectively negative, caveats to relying on NR. And not only is the amount of acceptable NR subjective, but it can be applied to every camera in order to increase their shadow DR numbers, not just Komodo. So it adds huge (and subjective) variables to an already contentious comparison.
    Downscaling *is* destructive. That doesn't mean it should be dismissed out of hand, nor that it should be accepted without comment. As long as the system parameters are sane and properly reported, they provide information for people who want to know "what can the system deliver?" and "what needs to be done to get that sort of performance?" Again, in some realms, advanced image processing is part of the craft. That's OK, as long as you have the tools, time, and treasure needed to get it done.
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  6. #76  
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    Quote Originally Posted by Michael Tiemann View Post
    Downscaling *is* destructive. That doesn't mean it should be dismissed out of hand, nor that it should be accepted without comment.
    Practically/comparatively it's not though; everything from sharpness and cleanliness to DR and colour is perceptibly improved by downscaling. It's a far more objective process, too. Besides, you always have to downscale with cameras that are 4k+ (it can't be avoided).

    Pretty sure combining data to fit into a smaller spot (downscaling) is objectively better than *removing* data in an attempt to remove artifacts (NR). Or no?

    Quote Originally Posted by Michael Tiemann View Post
    As long as the system parameters are sane and properly reported, they provide information for people who want to know "what can the system deliver?" and "what needs to be done to get that sort of performance?" Again, in some realms, advanced image processing is part of the craft. That's OK, as long as you have the tools, time, and treasure needed to get it done.
    Yeah, I don't disagree with that as a bonus, but it shouldn't be necessary to hit the advertised numbers... Conversely, I think RED's Chroma Noise Reduction & Flashing Pixel Removal is perfectly reasonable; it's imperceptibly destructive, r3d specific, and I think done at the debayer stage.

    The problem (for me) is that the application of NR in post is variable. Not only is the strength subjective to taste (before it seems plasticky/overly done), but each individual sensor/codec/camera might see the most benefit from different settings... Render time aside (which shouldn't be understated), maybe p6k could do 5-frame TNR before it looks bad, netting you two additional stops in the low-end, but Komodo only 1-frame/0.5-stop (or vice versa)... And it also ignores that a lot of raw/digital cinema cameras don't need additional NR to achieve their advertised DR or have an even highlight range.

    Hence why I lean more in the direction that the (potential) benefits of NR should be considered a bonus - again, part of the "+" like the mono-ish highlight stops should be.
    Last edited by Mike P.; 01-24-2021 at 06:11 PM.
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  7. #77  
    Quote Originally Posted by Mike P. View Post

    The problem (for me) is that the application of NR in post is variable. Not only is the strength subjective to taste (before it seems plasticky/overly done), but each individual sensor/codec/camera might see the most benefit from different settings... Render time aside (which shouldn't be understated), maybe p6k could do 5-frame TNR before it looks bad, netting you two additional stops in the low-end, but Komodo only 1-frame/0.5-stop (or vice versa)... And it also ignores that a lot of raw/digital cinema cameras don't need additional NR to achieve their advertised DR or have an even highlight range.

    Hence why I lean more in the direction that the (potential) benefits of NR should be considered a bonus - again, part of the "+" like the mono-ish highlight stops should be.
    I see it exactly the same way, thats why we measure "pure" RAW files (without NR) and also do not downscale, we measure DR at native resolution. Also, no highlight recovery is counted in the DR measurements (as color information is not fully there any more). Again, its all about "usable" stops.
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  8. #78  
    Incoming 2p worth...

    This is serving to highlight how people see different tests and there's nothing right or wrong here. Personally i think it's difficult to boil performance down to 1 number because there is so much detail in that number lost.

    CineD chooses to publish a number where they feel they are showing usable stops. And by useable they mean that each of the chips has it's own colour information in. This means that none of the RGB channels has clipped. You can see from all the charts previously in the French(?) test that the Alexa appears to show colour information higher up. The point about using WB to separate the RGB colours reveals if those colours are identical (meaning that they have been mathematically generated because the underlying channel clipped) or not.

    Personally i disagree with this, and i think any test should really show a number of figures. The chart range (the highest figure), the colour range (the cined figure) and maybe one with highlights in (which i would call usable, taking noise floor into account).

    I do also disagree with not doing NR. With the same data there's at least another stop, stop and half in the shadows. NR is part of almost every camera whether it's onboard or in post. And i think highlight reconstruction should be factored in because you cannot get an image without it being in there and also in 99% of uses rolling to a solid colour is what you want.

    But there's nothing wrong with the test that was done (revised one!) IMHO.

    Unless as Phil says there are better ways of standardising highlight and shadow points that come with the chart - because we don't really know where the clip point is.

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  9. #79  
    Quote Originally Posted by Mike P. View Post
    Practically/comparatively it's not though; everything from sharpness and cleanliness to DR and colour is perceptibly improved by downscaling. It's a far more objective process, too. Besides, you always have to downscale with cameras that are 4k+ (it can't be avoided).

    Pretty sure combining data to fit into a smaller spot (downscaling) is objectively better than *removing* data in an attempt to remove artifacts (NR). Or no?



    Yeah, I don't disagree with that as a bonus, but it shouldn't be necessary to hit the advertised numbers... Conversely, I think RED's Chroma Noise Reduction & Flashing Pixel Removal is perfectly reasonable; it's imperceptibly destructive, r3d specific, and I think done at the debayer stage.

    The problem (for me) is that the application of NR in post is variable. Not only is the strength subjective to taste (before it seems plasticky/overly done), but each individual sensor/codec/camera might see the most benefit from different settings... Render time aside (which shouldn't be understated), maybe p6k could do 5-frame TNR before it looks bad, netting you two additional stops in the low-end, but Komodo only 1-frame/0.5-stop (or vice versa)... And it also ignores that a lot of raw/digital cinema cameras don't need additional NR to achieve their advertised DR or have an even highlight range.

    Hence why I lean more in the direction that the (potential) benefits of NR should be considered a bonus - again, part of the "+" like the mono-ish highlight stops should be.
    Ok so what about shooting 8k, do signal cleaning within 4 pixels and then downsample to 4k... Now such signal has not "lost" or been treated destructivly compared to a camera that just captured 4k at sensor level. On the conterary the 8k downscaled to 4k benefit heavily with almost four times better guess work for the debayering process and the noise reduction done has not really caused any lost any info compared to the straight 4k capture, on the conterary.

    If comparing cameras you kind of need to bring them to a common ground before comparing, which is difficult so yes, it´s hardly ever just cameras that is being compared but also the post process, or the in camera baked process versus what could be done in post or what have you.
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  10. #80  
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    So WHY it's a secret how exposure was measured? Was it the same for different cameras or not?
    It's raw, because of that we expose as we want is very controversial statement.
    Exposuring 50D and 500T with the same exposure will favour one or other depending which was taken as a reference if it was printed with standard printer lights.
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