Page 3 of 11 FirstFirst 1234567 ... LastLast
Results 21 to 30 of 103
  1. Collapse Details
    #21
    Senior Member
    Join Date
    Jan 2006
    Location
    Nashville, TN
    Posts
    1,366
    Default
    Quote Originally Posted by TheDingo View Post
    I suspect that it's not the same as a 14-bit RAW image, but the Logarist color space does seem a lot better with 8-bit and 10-bit footage than anything else I've worked with.

    I'm guessing that higher precision math is part of why Logarist works better, and maybe why it's slower on some computers.
    The precision of the math use to make adjustments is a function of the NLE. As long as the color space is capable of holding all of the desired colors, Resolve is working with MORE than enough precision for any reasonable transformation.


    Reply With Quote
     

  2. Collapse Details
    #22
    Senior Member
    Join Date
    Jan 2011
    Posts
    251
    Default
    Quote Originally Posted by joe12south View Post
    - The NLE is working at high precision (at least 16bit) and a "wide" internal gamut. How do these LUT's make doing transforms "better"?
    - If what you're doing is transforming to a different color space, then isn't knowing the input camera's color space important? For example, the GH4 can use either sRGB or aRGB. Picture profile settings like saturation don't change the color space...why does the latter matter but not the former?
    - How is this easier? It's a minimum of 2 extra steps in FCPX for every single clip. For what gain?
    - I don't understand how this would help rescue white balance any better than you can without it? Certainly not like Lightroom (or Premiere for that matter) does with a RAW file. The color error is baked into the non-raw file, and is going to be destructive no matter what.
    - How is this different than the standardized LOG LUT's you released earlier?

    Sorry if I sound skeptical, but the language around this "LUT system" is very opaque, and we've all been bitten by LUT's that promise to be miracle cures. I'm sincerely trying to understand why it's worth the extra work. If there are real, meaningful benefits, it would be great to know how to capitalize on them.
    How do these LUTs make color correction better? Here's a concrete example. Say you underexposed a shot by 2/3 of a stop, by which I mean that if the ISO setting or the exposure would have been 2/3 of a stop higher, the shot would have turned out just how you wanted. Using normal color correction tools, only a specially shaped curve could fully correct that. Using lift/gamma/gain or some other shadow/mid/highlight tools you could come pretty close, except in the highlights near the clipping point. In Logarist, you just drag the offset slider up until the image is as bright as you want. It's a simple one-dimensional control, instead of a complex curve or separate low/mid/high adjustments. The result in Logarist will be nearly identical to increasing the ISO setting in the camera.

    To correct white balance with traditional tools, you need to correct the shadows, midtones, and highlights separately if you want to achieve the same color balance across the whole image. In Logarist, it's just one color control for the entire image.

    Color is baked into a non-raw file. But when you know how the camera did its transformation from raw sensor channel values to color values, that transformation can be inverted, taking the image from colors back to the raw domain. That's what I do here, though not all the way back to raw. I transform the camera's color values back to scene referred linear color, which is one step removed from raw sensor channel values. Of course the end-to-end transformation is not lossless. It's not the same as having a raw image. It's been de-bayered, sharpened, noise reduced, clipped, and quantized, and compressed. But that doesn't mean it's bad. A 10-bit uncompressed camera log recording isn't raw, but anyone would be hard pressed to tell the difference. In terms of color correction, a high precision log space with an extended range of highlights gives you nearly everything that the raw image had.

    To use still photography as an analogy, would you shoot JPEG and bring that into Photoshop for color correction? It's far better to shoot raw, use Adobe Camera Raw as your first pass, and then make additional changes in Photoshop. Logarist isn't quite the same as shooting in raw, but it's closer.

    Knowing the camera's color space is important in Logarist, and that's why I have dozens of different input transforms covering as many cameras as I could. On the GH4, the sRGB / Adobe RGB setting only affects still images. The color space of the GH4's video output is determined by the Photo Style setting, including all of the color and contrast adjustments.

    Logarist is similar to my previous log LUTs, but this time I have explicit support for several different video apps, lots more cameras, and I've developed new methods for handling highlights.

    In FCPX, after making corrections to one clip, you can save the effects as a preset so they can be applied to more clips in a single step. So the extra work is really just for the first clip, and after that it's less work.

    No one is twisting your arm here. If your style of shooting lets you get the color and exposure almost perfect in the camera and you already have LUTs that give you the look you want, you're not going to benefit much from more advanced color correction tools. If you're comfortable working the way you have been, by all means keep doing it. I can't convert all the skeptics. I just know that for me, this new way of working has proven much better, and I wanted to share that with people.


    3 out of 3 members found this post helpful.
    Reply With Quote
     

  3. Collapse Details
    #23
    Senior Member
    Join Date
    Jan 2011
    Posts
    251
    Default
    Quote Originally Posted by Thomas Smet View Post
    So far I'm really impressed with how this handles V-log from the GH4. Cine-D seems to clip much easier than it does with manual grading or when using Leeming LUT. I know the shots are not clipped because I can recover them and other luts do not show this.

    Are there recommended exposure levels you suggest for Cine-D to avoid this?

    Same but opposite issue with V-log. When using these luts my shots get a lot darker than they do with the Leeming lut, Panasonic lut or my own manual grading. Are their recorded exposure levels that are different from normal V-log luts to shoot with or is it natural to be that much darker and I grade in between?

    Finally why do you suggest only adjusting the global exposure setting in the FCPX color board and not the highs and shadows? I find this to be very limiting in grading by not tweaking the highs and shadows.

    By the way this lut is extremely slow on my 2012 i7 iMac with 24GB ram and a 2GB GTX680m GPU. Not slow in terms of playback but FCPX really locks up for a good 20 seconds when I apply the first lut. I assume there is a lot going on in the background vs other luts to make it run that slow.
    Logarist isn't trying to match the highlight range of your source to the highlight range of the output. It's mapping the middle grey level. So if you just add the Logarist LUTs and do nothing else, you are likely to see clipping, and it may well be lighter or darker than you were used to seeing with other LUTs. You'll pretty much always want to apply some exposure compensation in Logarist. That's the first and most basic correction to apply.

    How to set the exposure in the camera when shooting for Logarist is totally up to you. Whatever you decide, you can compensate in Logarist. So the exposure setting really comes down to the fundamentals of dynamic range:

    • Increasing the exposure decreases the highlight range (lowers the clipping point)
    • Decreasing the exposure increases noise

    These are the two fundamental forces that you must decide how to balance. There is no single right or wrong answer. You must decide how important noise and highlight range are to you.

    The Logarist LUTs are all high precision, with a minimum of 262,144 points. That's probably why they take so long to load in mLut. On my test machine, a 2012-era Macbook Air md232ll/a, it took about 10 seconds to load a LUT in mLut. After that, corrections were near real-time on the quarter-screen preview.

    In FCPX, my instructions say to use the Global color and exposure control, because those act as offsets, which is mathematically how you make corrections in a log space that will be equal across the entire color range. The Shadows, Midtones, and Highlights adjustments won't work in the log space the way you are used to. You can add another Color Correction effect after the second mLut effect, and make your shadow/mid/highlight adjustments in the display color space just like you always did before.


    3 out of 3 members found this post helpful.
    Reply With Quote
     

  4. Collapse Details
    #24
    Senior Member
    Join Date
    Oct 2008
    Location
    New York
    Posts
    650
    Default
    What about the LUT's used on set? Where in this workflow does it get applied? After all I'd like the image to look the same as when monitoring on set. Having to bring them there from what Logarist pair of LUT's creates as a starting point is another step in the workflow. Or am I missing something?


    Reply With Quote
     

  5. Collapse Details
    #25
    Senior Member
    Join Date
    Jan 2011
    Posts
    251
    Default
    Quote Originally Posted by broughtonfilm View Post
    What about the LUT's used on set? Where in this workflow does it get applied? After all I'd like the image to look the same as when monitoring on set. Having to bring them there from what Logarist pair of LUT's creates as a starting point is another step in the workflow. Or am I missing something?
    If you want a monitor LUT for on-set monitoring that will match what Logarist produces, there's a way to create it with Resolve.

    Put the Logarist input transform on one corrector node, the output transform one another corrector node, and then put whatever baseline corrections you normally apply in between. For example, if your preferred workflow is to over-expose by a stop in the camera and then bring it down by a stop in Logarist, you will need to apply one stop of negative exposure compensation in between the two Logarist LUTs. Then export the entire correction chain as a new LUT file. You can load that LUT in your monitor.


    1 out of 1 members found this post helpful.
    Reply With Quote
     

  6. Collapse Details
    #26
    Senior Member Thomas Smet's Avatar
    Join Date
    Jul 2005
    Location
    Colorado
    Posts
    2,397
    Default
    Quote Originally Posted by balazer View Post
    Logarist isn't trying to match the highlight range of your source to the highlight range of the output. It's mapping the middle grey level. So if you just add the Logarist LUTs and do nothing else, you are likely to see clipping, and it may well be lighter or darker than you were used to seeing with other LUTs. You'll pretty much always want to apply some exposure compensation in Logarist. That's the first and most basic correction to apply.

    How to set the exposure in the camera when shooting for Logarist is totally up to you. Whatever you decide, you can compensate in Logarist. So the exposure setting really comes down to the fundamentals of dynamic range:

    • Increasing the exposure decreases the highlight range (lowers the clipping point)
    • Decreasing the exposure increases noise

    These are the two fundamental forces that you must decide how to balance. There is no single right or wrong answer. You must decide how important noise and highlight range are to you.

    The Logarist LUTs are all high precision, with a minimum of 262,144 points. That's probably why they take so long to load in mLut. On my test machine, a 2012-era Macbook Air md232ll/a, it took about 10 seconds to load a LUT in mLut. After that, corrections were near real-time on the quarter-screen preview.

    In FCPX, my instructions say to use the Global color and exposure control, because those act as offsets, which is mathematically how you make corrections in a log space that will be equal across the entire color range. The Shadows, Midtones, and Highlights adjustments won't work in the log space the way you are used to. You can add another Color Correction effect after the second mLut effect, and make your shadow/mid/highlight adjustments in the display color space just like you always did before.
    Awesome stuff. Thanks for the explanation.


    Reply With Quote
     

  7. Collapse Details
    #27
    Senior Member Thomas Smet's Avatar
    Join Date
    Jul 2005
    Location
    Colorado
    Posts
    2,397
    Default
    Quote Originally Posted by balazer View Post
    How do these LUTs make color correction better? Here's a concrete example. Say you underexposed a shot by 2/3 of a stop, by which I mean that if the ISO setting or the exposure would have been 2/3 of a stop higher, the shot would have turned out just how you wanted. Using normal color correction tools, only a specially shaped curve could fully correct that. Using lift/gamma/gain or some other shadow/mid/highlight tools you could come pretty close, except in the highlights near the clipping point. In Logarist, you just drag the offset slider up until the image is as bright as you want. It's a simple one-dimensional control, instead of a complex curve or separate low/mid/high adjustments. The result in Logarist will be nearly identical to increasing the ISO setting in the camera.

    To correct white balance with traditional tools, you need to correct the shadows, midtones, and highlights separately if you want to achieve the same color balance across the whole image. In Logarist, it's just one color control for the entire image.

    Color is baked into a non-raw file. But when you know how the camera did its transformation from raw sensor channel values to color values, that transformation can be inverted, taking the image from colors back to the raw domain. That's what I do here, though not all the way back to raw. I transform the camera's color values back to scene referred linear color, which is one step removed from raw sensor channel values. Of course the end-to-end transformation is not lossless. It's not the same as having a raw image. It's been de-bayered, sharpened, noise reduced, clipped, and quantized, and compressed. But that doesn't mean it's bad. A 10-bit uncompressed camera log recording isn't raw, but anyone would be hard pressed to tell the difference. In terms of color correction, a high precision log space with an extended range of highlights gives you nearly everything that the raw image had.

    To use still photography as an analogy, would you shoot JPEG and bring that into Photoshop for color correction? It's far better to shoot raw, use Adobe Camera Raw as your first pass, and then make additional changes in Photoshop. Logarist isn't quite the same as shooting in raw, but it's closer.

    Knowing the camera's color space is important in Logarist, and that's why I have dozens of different input transforms covering as many cameras as I could. On the GH4, the sRGB / Adobe RGB setting only affects still images. The color space of the GH4's video output is determined by the Photo Style setting, including all of the color and contrast adjustments.

    Logarist is similar to my previous log LUTs, but this time I have explicit support for several different video apps, lots more cameras, and I've developed new methods for handling highlights.

    In FCPX, after making corrections to one clip, you can save the effects as a preset so they can be applied to more clips in a single step. So the extra work is really just for the first clip, and after that it's less work.

    No one is twisting your arm here. If your style of shooting lets you get the color and exposure almost perfect in the camera and you already have LUTs that give you the look you want, you're not going to benefit much from more advanced color correction tools. If you're comfortable working the way you have been, by all means keep doing it. I can't convert all the skeptics. I just know that for me, this new way of working has proven much better, and I wanted to share that with people.
    Completely agree about 10bit log getting very close to raw. The famous color engineer Charles Poynton even has stated that 10 bit log has about 99% of the useful information from 12bit raw.


    1 out of 1 members found this post helpful.
    Reply With Quote
     

  8. Collapse Details
    #28
    Senior Member
    Join Date
    Oct 2008
    Location
    New York
    Posts
    650
    Default
    Quote Originally Posted by balazer View Post
    If you want a monitor LUT for on-set monitoring that will match what Logarist produces, there's a way to create it with Resolve.

    Put the Logarist input transform on one corrector node, the output transform one another corrector node, and then put whatever baseline corrections you normally apply in between. For example, if your preferred workflow is to over-expose by a stop in the camera and then bring it down by a stop in Logarist, you will need to apply one stop of negative exposure compensation in between the two Logarist LUTs. Then export the entire correction chain as a new LUT file. You can load that LUT in your monitor.
    Thank you for your answer. Yeah, that scenario is clear to me but I was talking about using existing LUT's, let's say I have LUT's which I have been using and would like to continue using them. I guess there's a way to translate them into this new colorspace and then generating a new LUT for use on set would be straightforward but I can't quite wrap my head around how I would do translation part of it. BTW, I ask these questions without any sarcasm, I'm intrigued by this workflow (as well as ACES, which is something I have to read more about).


    Reply With Quote
     

  9. Collapse Details
    #29
    Senior Member Thomas Smet's Avatar
    Join Date
    Jul 2005
    Location
    Colorado
    Posts
    2,397
    Default
    I once tried combining luts in Resolve to bake them together for a friend with a Flame and he said it didn't work. I only have a Ninja Blade which has built in crude luts and no ability to load custom luts so I haven't been able to test that workflow myself.


    Reply With Quote
     

  10. Collapse Details
    #30
    Senior Member
    Join Date
    Jan 2011
    Posts
    251
    Default
    Quote Originally Posted by broughtonfilm View Post
    Thank you for your answer. Yeah, that scenario is clear to me but I was talking about using existing LUT's, let's say I have LUT's which I have been using and would like to continue using them. I guess there's a way to translate them into this new colorspace and then generating a new LUT for use on set would be straightforward but I can't quite wrap my head around how I would do translation part of it. BTW, I ask these questions without any sarcasm, I'm intrigued by this workflow (as well as ACES, which is something I have to read more about).
    If you have existing LUTs that you want to integrate with Logarist, it really depends on what that LUT was doing. LUTs can do three things, broadly:
    • change the colors
    • change the color space
    • display rendering

    If you have a "look" LUT that you apply to a display-ready image, you can still use that with Logarist. Just apply the LUT after the Logarist-to-BT.709 LUT. Such a LUT operates in the display color space and is only changing the colors.

    If you have a LUT that goes from a camera log space to a display color space, it's doing color space transformation, display rendering, and maybe also changing the colors. There's no good way to integrate that kind of LUT into the Logarist workflow. Logarist depends on having an extended highlight range and scene-referred color. Once you're in the display color space, you lose those.


    1 out of 1 members found this post helpful.
    Reply With Quote
     

Page 3 of 11 FirstFirst 1234567 ... LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •