Logarist Color Correction for Vegas Pro

Comments

Rich Parry wrote on 7/18/2017, 11:24 AM

Blazer,

Thanks for the reply and explanation on the process you use to create a LUT. Sounds like in those cases where you don't have specs from the manufacturer, it is a fairly tedious and time consuming process which is what I thought it might me.

Thank you for your work,

Rich

balazer wrote on 7/19/2017, 1:47 PM

hawaiifilmschool posted this video of how he uses Logarist to color correct S-Log3 footage in Vegas:

 

karma17 wrote on 8/6/2017, 1:59 AM

Awesome to see that you added Hypergamma 7 and 8 for Sony cameras! That's so cool.

Is there any way to add D-LOG for the DJI Phantom 3 Advanced? I am having a terrible time with my 4k DJI footage in post and can't really seem to make it pop at all.

Anything I can do to help or support your cause, I'm in. I think what you are doing is fantastic!

 

 

balazer wrote on 8/6/2017, 3:09 AM

Thanks, karma17.

To profile a camera's color space I need to get my hands on the camera, and even then I'm not sure how I could profile a camera that doesn't have fully manual exposure control. Does the DJI Phantom 3 Advanced camera have that?

I suggest not using D-Log, and instead using one of the camera's standard color modes. You can color correct it using Logarist's BT.709 input transform.

karma17 wrote on 8/6/2017, 11:38 PM

I see. It has a fixed aperture of f2.8, so maybe out of luck. I am sure the Phantom 3s all have the same basic camera, but they give you the ability to record in 2k on Advanced and 4k on Pro. They all have the option to shoot in D-Log and same style options. D-Log is fairly flat, and D-Cinelike is just a little better. I might just shoot in Standard and use the 709 then. I have found horrendous aliasing on the Standard, but if you shoot 4k on the Pro and down-rez to hi def, it is mostly eliminated Thank you!!

Wolfgang S. wrote on 8/7/2017, 4:53 AM

Question: I understand that a good color management has a clear added value if I shoot in log - like slog. I really like the example above, showing FS7 slog3 footage and how that is graded to rec709.

I have tested that also with my 8-core system, and beside the fact that the performance requirements for 32bit floating point mode, 2 times LUTs and additional filters are huge for FS7 slog3 UHD 50p footage, I think it works nice.

But I am not sure if there is an added value if I shoot in rec709, as in the case of HG 7/8. Here it would be enough to correct the footage with the tools available in Vegas alone, since a color space conversion is not required.

Beside that I think it is great to have the profiles for HG7 and HG8 - because it gives another opportunity how to correct this footage. Thank you for that.

megabit wrote on 8/7/2017, 5:12 AM

I'm really curious what Jacob's answer will be to your question, Wolfgang. While inside the so much better performing (playback-wise) Resolve the Logarist workflow offers clear advantages at practically no performance penalty, the T/L playback slow-down in Vegas Pro unavoidable with 2 instances of VisionColor plugin working in a 32bit-float project is huge, and so the benefits must be assessed with this in mind. Again - in Resolve, the much better highlights preservation plus the wonderful, intuitive performance of the LOG color wheels which Logarist brings about is always worth it - even with non-log source footage; but in Vegas Pro? I'm skeptical, to say the least :(

Piotr

Wolfgang S. wrote on 8/7/2017, 7:05 AM

Piotr,

we mention different points, I think.

First, in Resolve you have some very clear advantages today:

  1. due to GPU usage a huge playback performance
  2. log instruments beside the primary color corrector
  3. but with Resolve 14 beta 6 now also ACES 1.03 - what works great both for grading to rec.709 but also to rec.2020. Understanding quite well what Jacob has said about the difference between ACES but also Logarist, both systems are color management systems that can be utilized for great and similiar results

For Vegas in its actual build, we do not have ACES 1 yet - so the Logarist is a great alternative I think. To my opinion, Vegas is not a grading application as it is Resolve - but it is a superior editor. Even if Resolve has become better here. So what I would like to have are better grading capabilities for my slog3 - and that is what Logarist delivers by now.

But the added value is here a clear color space conversion - at the moment down to rec709 in Logarist (beside the LUT that Jacob has sent you as I have read elsewhere).

So all that is great. But to my limited unterstanding the hypergamma curves are within rec709 - so I do not need a color management system to edit HG. I edit HG in an 8bit projekt in Vegas, and apply all board instrumenst that I have availabel. For the final rendering I switch to 32bit floating point in the project properties, and that is it. So the question is - what is the point that I miss here?

balazer wrote on 8/7/2017, 1:21 PM

HyperGammas are not BT.709. HyperGammas need correction to be displayed correctly. They are somewhat similar to BT.709, so you can do a quick and dirty correction by hand using levels and curves. I'd argue the corrections are still easier and more accurate using Logarist than by hand. And in Logarist, the color correction process is always the same, no matter which color space the video was recorded in. HyperGammas become a great alternative to S-Logs, because now you have a choice to use a color managed workflow or do things by hand. And when you're not using color management, even before correction, HyperGammas give you an image on your screen that more closely resembles the final output, instead of the low-contrast low-saturation image you see when you try to display an S-Log directly. HyperGammas are the best of both worlds.

The VisionColor LUT Plugin is slow, I know. I never find this to be an issue in practice. Color correction is always the last thing I do, after all of the editing. After color correction is done, I usually don't need to play the video in Vegas, so playback speed is not an issue. If for some reason I do need to play the video in Vegas, I can bypass all effects with one click, and maybe switch the project to 8-bit mode, and everything is fast again. If you want everything to be fast while you're doing color correction, switch to Resolve, or put some pressure on Magix to give us a GPU-accelerated LUT effect. It's kind of pathetic that we need to rely on a 3rd-party plugin in this day and age for something as basic as loading LUTs.

You can use ACES 1.0 in Vegas with my OpenColorIO config at http://www.jbalazer.com/aces-in-sony-vegas . But be warned, if you think the VisionColor LUT Plugin is slow, Vegas's OpenColorIO integration is even slower.

Video editing is full of compromises. None of the tools we use are even close to perfect. Just find the set of compromises that works best for you.

Wolfgang S. wrote on 8/7/2017, 3:53 PM

Fine, but what gammut is HG then? I am not talking about the higher DR of HG, but mainly the color space used by HG.

balazer wrote on 8/7/2017, 4:01 PM

A color space is more than just a gamut.

On the FS7, HyperGammas use the BT.709/sRGB gamut. On Sony Alpha cameras, the gamut can be selected independently of the gamma.

Wolfgang S. wrote on 8/8/2017, 1:20 AM

Sure, but that is what I said: HG uses the rec709 color space. So, if you grade HG in an NLE in rec709, it should be fine. There is a higher DR, going beyond the 6 stops of our classical rec709 displays, but this is the advantage of HG.

balazer wrote on 8/8/2017, 4:19 AM

Wolfgang, you are using the terms "color space" and "gamut" interchangeably, but as I said, they are not the same thing. A color space is more than just its gamut, or the chromaticities of its primaries. HyperGammas as recorded on the FS7 have the same primary chromaticities as BT.709, but that's all they have in common with BT.709. HyperGammas are not just BT.709 with more dynamic range. They are different gamma curves, with different shapes. They bear some resemblance to the BT.709 gamma curve, but they are different enough to require transformation to be displayed correctly on a standard display. And there are eight different HyperGammas, each requiring different transformation to be displayed properly. You can do a quick and dirty transformation with standard color tools, and in many cases it will look decent, but it's not an accurate reflection of BT.709. It certainly helps that the primaries are the same in the FS7's HyperGammas and in BT.709. If they weren't, no standard color tools would even come close to making the correct transformation.

BT.709 has a lot more than 6 stops of dynamic range, and so do today's displays.

Wolfgang S. wrote on 8/8/2017, 6:13 AM

Wolfgang, you are using the terms "color space" and "gamut" interchangeably, but as I said, they are not the same thing. A color space is more than just its gamut, or the chromaticities of its primaries.

Because typically, both words "color space" and "gamut" tend to be used interchangeable - but I agree with you. It is more, it is the "full range of colours and brightness that can be either captured or displayed."

(Alister Chapman - http://www.alisterchapman.com/2014/05/06/what-is-a-gamut-or-color-space-and-why-do-i-need-to-know-about-it/)

In other publications gamut and range of colors are used completeley interchangeable:

"Whichever display you choose should be capable of supporting the exakt gaumut (range of colors) and gamma (luma reproduction) required for the standard of video you're going to be working in"

Alexis Van Hurkman, Color Correction Handbook 2nd edition, page 34

So typically, they separate color and luma - what is fine for me.

HyperGammas as recorded on the FS7 have the same primary chromaticities as BT.709, but that's all they have in common with BT.709. HyperGammas are not just BT.709 with more dynamic range. They are different gamma curves, with different shapes. They bear some resemblance to the BT.709 gamma curve, but they are different enough to require transformation to be displayed correctly on a standard display.

In understood following, as stated by Chapman: "Sony has always stated that this sensor is essentially a “709” sensor. The sensor in Sony’s PMW-F55 can capture a much greater color range (gamut) than the F5, FS5 and FS7, only the F55 can actually capture the full Rec-2020 color space, the FS7 II sensor cannot. It’s very difficult to measure the full color gamut of a sensor, but from the tests that I have done with the F5 and FS7 I estimate that this sensor can capture a color gamut close to that of the DCI-P3 standard, so larger than Rec-709 but not nearly as large as Rec-2020 (I’d love someone to provide the actual color gamut of this sensor)."

http://www.xdcam-user.com/2016/11/what-does-rec-2020-on-the-pxw-fs7-ii-really-mean/

In the FS7 one has the choice between rec709 (if you select nothing), or slog2/3 with sgamut, sgamut3 and sgamut3.cine. If that captures the DCI P3 only, fine for me because that is what our latest today displays are able to show.

But for the hypergamma curves you select nothing, so it is within the colors of rec709 to my opinion. But I have not measured that nore have I found clear statements (beside that above by Alister) what the FS7 records if you set it to HG.

And there are eight different HyperGammas, each requiring different transformation to be displayed properly. You can do a quick and dirty transformation with standard color tools, and in many cases it will look decent, but it's not an accurate reflection of BT.709. It certainly helps that the primaries are the same in the FS7's HyperGammas and in BT.709. If they weren't, no standard color tools would even come close to making the correct transformation.

You will be right here - but my question is: how large is the error? I will make some tests to get here a better impression I think. Because that is what is important really for our workflows - how significant is the error we have chosing to edit HG in an 8bit project for example in Vegas, without using a superior color management?

BT.709 has a lot more than 6 stops of dynamic range, and so do today's displays.

What kind of today displays? For HDR displays I agree fully. But for out good old HDTVs, based still on rec709? For those displays typically everbody states that they have 6 stops only - what is an argument or HDR.

Do you know a sound documentation for the HG-curves? I have not found that really.

Wolfgang S. wrote on 8/8/2017, 12:09 PM

Have done some Tests with HG8 footage. The main Change that I see is that the luminance Level is increased if I apply the Logarist.

karma17 wrote on 8/9/2017, 1:24 AM

Read your post on lastest DVX user and found it extremely helpful.

I did have just one last question.

When you are using Logarist and applying Brightness and Contrast, and Channel Blend between the two LUTs in the chain, if you want to add additional effects is it okay or appropriate to add additional effects between the LUTs, or is that too much? For instance, a lens flare effect, film grain effect, or a secondary correction to just one part of the image, would you do those between the LUTS?

Thanks.

 

 

 

balazer wrote on 8/9/2017, 12:52 PM

karma17, yes, you can use other filters in the Logarist color space. Generally speaking, if the intent is to alter brightness or colors, it will work well in the log space. Curves work well. Secondary color correction may work, though I'm not sure if the Vegas filter has fine enough controls for the log space. Any filter mimicking physical processes of light, e.g. lens flare, lens blur, or noise, are not things you'd want to use in a log space. Ideally those would be performed in a linear space.

Filters behave differently in the log space, which is the whole point of having the log space. You'll just need to experiment and see if the filter works better in the log space (between the LUTs) or in the display space (after the BT.709 LUT).

balazer wrote on 8/26/2017, 5:17 PM

Logarist now supports Canon Wide DR gamma.

set wrote on 8/28/2017, 10:17 PM

@balazer, you may want to update the Logarist workflow of yours since new the Vegas Pro 15 now have its' own LUT plugin, with strength slider function as well.

(Also the ACES 1.0 color space as well)

 

Looking forward for your updated unique color workflow!

balazer wrote on 8/29/2017, 2:48 AM

Logarist can be used with Vegas Pro 15's new VEGAS LUT Filter instead of the VisionColor LUT Plugin. The color correction is identical. Leave the Strength set to 1.0. The VisionColor LUT Plugin also works in Vegas Pro 15. I've updated the documentation at logarist.com.

Unfortunately the new filter is no faster than the VisionColor LUT Plugin, which was already slow. Magix apparently did little to try to optimize the performance of the new filter.

altarvic wrote on 8/29/2017, 3:23 AM

I suspect that the MAGIX LUT plugin is actually a modified VisionColor LUT plugin (since the latter is no longer available on their website)

balazer wrote on 8/29/2017, 1:39 PM

No, the VisionColor LUT Plugin was always available. It was free through their old cart system as of yesterday. Now it's €2.49 at https://vision-color.com/products/#plugins .

karma17 wrote on 10/1/2017, 4:34 AM

Hi again.

I was just curious when you convert out of the Logarist color space, under the BT 709 options, what are the differences HighComp and LumaComp options and the .33, .66, 1.0, etc options. I believe you mentioned somewhere you preferred the .66 choice. But I don't remember if that was HighComp or Luma Comp. I was wondering if some people are choosing the wrong options and thinking something is wrong when they weren't paying attention to the settings. But then I started wondering myself what the differences were exactly.

Also, do you believe that Da Vinci Resolve has something that makes it uniquely superior for color correction that cannot be achieved in other video editing programs? Some people seem to think that only Da Vinci Resolve can do precise color grading, but I'm not convinced of that. Isn't math math no matter the program? Da Vinci Resolve has 32 bit floating, but doesn't Vegas too? Just wondering if you have an opinion on that. Personally, I don't believe that someone could tell what program was used to do color correction. I just don't think there is any way to discern that.

Thank you!

 

balazer wrote on 10/1/2017, 2:49 PM

Logarist's highlight compression curves are described at https://www.logarist.com/#Display_Rendering_and_Highlight_Compression_in_Logarist . There's no right or wrong choice; just different looks that depend on your aesthetics and the scene.

When you stick to the basic corrections of exposure compensation, white balance correction, and contrast adjustment, what Vegas Pro does is identical to what Resolve does. Resolve has a lot of color tools that go beyond what's available in Vegas Pro. Resolve's shadow and highlight log color wheels, for example, work very well in a log color space and have no simple analog in Vegas Pro. Resolve's various curves like Hue Vs Sat and Hue Vs Hue do things that aren't easy to achieve with Vegas Pro's secondary color correction effect.