Better LUT for good skin tones - for Odyssey 7Q+ & FS700 ?

[pythonman]

Hi,

With my Odyssey 7Q+ (attached to my FS700) I've been using the supplied LUTs from Convergent Design, namely either the "SONY_EE_SL2_L709A-1" or "SONY_EE_SL2_L709A-2" (depending on exposure levels). I apply the LUT in Premiere in the new Lumetri panel. I then will manually adjust for each clip as appropriate.

I shoot S-Log2 and record in ProRes. I always try to get a good white balance, but with the supplied LUT I find the skin tones to be very peachy/pink in colour, plus any blue to become very turquoise. Yes, I realise it is possible for me to create my own LUT, but are there any LUTs readily available that would give me a better skin tone (and more accurate blue) out-of-the-box? Or am I doing anything wrong? Thank you!

Here is a typical example (without, and then with the LUT applied). No additional adjustments have been made in this example, just the LUT.

 

[taynos]

Hi,

With my Odyssey 7Q+ (attached to my FS700) I've been using the supplied LUTs from Convergent Design, namely either the "SONY_EE_SL2_L709A-1" or "SONY_EE_SL2_L709A-2" (depending on exposure levels). I apply the LUT in Premiere in the new Lumetri panel. I then will manually adjust for each clip as appropriate.

I shoot S-Log2 and record in ProRes. I always try to get a good white balance, but with the supplied LUT I find the skin tones to be very peachy/pink in colour, plus any blue to become very turquoise. Yes, I realise it is possible for me to create my own LUT, but are there any LUTs readily available that would give me a better skin tone (and more accurate blue) out-of-the-box? Or am I doing anything wrong? Thank you!

Here is a typical example (without, and then with the LUT applied). No additional adjustments have been made in this example, just the LUT.

View attachment 107018View attachment 107017

Totally agree. I don't like the SLOG2>REC709 lut for that very reason. I've been using the Arri_EE_LOG_R709. Its warms everything up but really gives nice fleshy skin tones. Then I dial it back in resolve. I'd rather have fleshy warm skin tones and either add blue to the background / surrounding than have to fix skin tones. The Arri Lut also adds some nice contrast that I like looking at when I operate.

And I don't ever do white balance, rather, in whatever lighting situation I am in, I bring up the manual color temp adjustment in the menu setting and point the camera at a stand in , pa or talent and then adjust the color temp so I get a nice fleshy skin tone depending on the subject and their lighting. And then I lock that in.

 

[Kyron]

Glad I'm not the only one. I don't use the CD slog2 to L709 -1 or -2 anymore for this reason. Skin looks weird and there's something strange in the green/blues going on. It's not very contrasty either.

Still trying to find a good LUT so I hope this discussion really opens up and people share their secret sauce

 

[Noel Evans]

Generic LUTS assume 1 thing. Everything is shot the same as the scenario in which the LUT was created. Lighting, people's skin tones, shooters intention are all different for each shoot / each shooter, so a generic LUT is not the way to go in most cases.

 

[Kyron]

Well apart from "Don't use generic LUT's," maybe there's at least a better one than the current offering?
I've tried shooting with an x-rite chart in Resolve but the colours it produces are crazy saturated and look quite different to the real locations I shot.
I may be doing it wrong, but there aren't that many options in the software so I'm not 100% sure :\

Roger Deakins for example uses the same LUT or a slight variation of it for most of his recent films while shooting.
"the LUT that E Film developed for me is the most 'pleasing' in terms of colour and tonal values. For 'Skyfall' we added a little saturation and for 'Prisoners' we took away saturation and added a little contrast. Very insignificant changes in each case as I like to start my DI with what I consider a 'normal' image that reflects the way I am lighting."

So it's not really about a grade or a look so much, but about representing a "normal" image on-set. I feel the current LUT's fall short here.

 

[pythonman]

What really has struck me is the inaccurate colours that's happening somewhere along the path. I recently had to shoot some internal videos for a well know clothing retailer here in the UK. What was really important was to get the colours accurate so that their viewers could see exactly the colour offerings available on various clothing lines. I shot staff presenting quick introductions to each new item of clothing along with a close-up of the item itself, very simple stuff. I lit the space with daylight kinos with no other lighting in the space to mess up the colour temperature. I performed a proper white balance using a Lastolite grey pop-up.

If I turned off all picture profiles on the FS700 then the colours showing on the FS700's LCD screen looked very accurate to me, a pink t-shirt looked the same colour on the screen as it did in the room. But if I put the FS700 into PP7 (SLOG-2) so that I could use the Odyssey then the colours were wrong using any of the SLOG2 LUTs on the 7Q+.

I have a feeling it's not just the LUT that's wrong in my case. I have tried to do a manual grade in Lumetri using no LUT, by manually making adjustments in the various panels, and I can get it closer to reality with some better looking skin tones. But some colours are still inaccurate. If I just take the straight SLOG2 video with no LUT and increase the saturation to reality-looking levels, and add some simple s-curve contrast, then the colours still don't look accurate either (the biggest issue I've found is the reds - they look too yellow in many cases).

Perhaps I need to open up Resolve and experiment more.

Any help will be appreciated. Thanks!

 

[ChadN]

For some reason, the Canon EE Cin LOG WDR Lut looks closest to what i'm seeing with my eye when i compare the two in person. But i don't want to use it, because it's designed for a whole different camera!

Anyway, i have trouble with Reds in general with the FS700/7Q. I'll shoot Slog 2 ProRes and Red looks Orange. Anyone have this?

 

[pythonman]

For some reason, the Canon EE Cin LOG WDR Lut looks closest to what i'm seeing with my eye when i compare the two in person. But i don't want to use it, because it's designed for a whole different camera!

Anyway, i have trouble with Reds in general with the FS700/7Q. I'll shoot Slog 2 ProRes and Red looks Orange. Anyone have this?

Exactly what I find - the reds have too much yellow in them with SLOG2. It's not just the case with the ProRes recordings on the Odyssey, it's also true when recording SLOG2 internally to AVCHD. Plus the colours are also wrong with REC709 800%. The most accurate colours I have found is with NO profile selected at all!!! It's a shame the Odyssey can't accept this signal.

So is there a solution? I'm so surprised this hasn't been discussed before - or maybe it has and I've missed it?

 

[pythonman]

Maybe if you could customise the S-Log2 PP on the FS700 it would help, perhaps adjust the hue of the red channel for example, never tried doing this myself. Although I don't think the Odyssey will accept a modified SLOG2 PP - will have to check.

 

[Nick_Shaw]

I worked with Convergent Design on the development of the Odyssey LUT system, and I converted many of the LUTs to make them suitable for use in the Odyssey.

All the LUTs Convergent Design provide are from the manufacturers of the respective cameras, and have simply been converted where necessary to make them behave in the Odyssey, and with ProRes material in Resolve, in a way which matches the equivalent in camera implementations. The exposure compensated variants are just mathematical transforms of the originals.

The LUT called SONY_EE_Slog2_LC709A.cube is derived from Sony's LUT called 2.From_SLog2-SGumut_To_LC-709TypeA.cube, published here. It was designed for S-Log2 material from the F65 and F55, which is in S-Gamut colour space. It is my belief that while the S-Log2 output of the FS700 matches the S-Log2 curve from those cameras, the colour space does not exactly match S-Gamut. Because the LUT is not getting exactly the expected input, it will not provide exactly the intended output.

I think it is best for Convergent Design to stick to only providing manufacturers' LUTs, or technical derivations of them. Any modified LUT would be substantially subjective. I would recommend people use the LC709A LUT as a start point, and make their own modified versions for the FS700 using the hue vs hue and hue vs sat curves in Resolve. One of my tutorial videos on the Convergent Design website shows how to save a LUT from Resolve to use in the Odyssey. I have also created some new documents and videos which will be published with the next Odyssey firmware update.

 

[pythonman]

Thank you Nick for the tips on what to do.

So I ordered a Datacolor SpyderCheck24 colour correction card, shot myself holding it, then imported the ProRes clip into Davinci Resolve 12. Made a quick grade using the Colour Match feature, which has the Datacolor card parameters built in. Brilliant! Skin tones now look very good and the reds look pretty accurate!! I exported a LUT using your video as a guide and added it to the Odyssey, looks great! Works in Premiere too. I have only tested with one shot, so will keep testing, but thanks!

 

[smoki138]

In last time i thing Slog2 and LUTs it's a big marketing...

In last time i use in FS700 color profile in OFF, and i record oryginal colors, and in Premiere i only add small contrast and saturation, and im very happy - speed and easy, no big noise.

I use more LUTs from TOPAZ like Kodak S-Log2, but i hate it. Blues looks horrible. i record in Odyssey 7Q in 4:2:2 Pro Res.

And i don't know i really don't like workflow with LUT.

I don't like red faces. If i see it in OFF profile camera i say to make up - please make --> make up, and girls look nice and white :3

And i don't know i'm studpied or what?
Maybe this is only marketing, and we make only more work and more and more...

 

[Mitch Gross]

Thank you Nick for the tips on what to do.

So I ordered a Datacolor SpyderCheck24 colour correction card, shot myself holding it, then imported the ProRes clip into Davinci Resolve 12. Made a quick grade using the Colour Match feature, which has the Datacolor card parameters built in. Brilliant! Skin tones now look very good and the reds look pretty accurate!! I exported a LUT using your video as a guide and added it to the Odyssey, looks great! Works in Premiere too. I have only tested with one shot, so will keep testing, but thanks!

Glad to hear the system works for you. This is exactly the way manufacturers state they intend for clients to use the tools, although many work out their own systems.

I suggest that you do this same process in tungsten and daylight balance, and perhaps with a daytime and nighttime setting. You may find some variations to your taste for this and adjust accordingly.

Back in the day when I shot and finished features on this stuff called film, I would set four standards for the production: Day Interior, Day Exterior, Night Interior, Night Exterior. Each would be exposed a certain way and each would be printed a certain way. I would insist that the dailies color timer not try to further "help" me and instead deliver exactly what we had agreed upon in testing during prep. The result was wonderfully consistent dailies and a very easy process of color timing the film in post.

 

[Nick_Shaw]

In last time i thing Slog2 and LUTs it's a big marketing...

In last time i use in FS700 color profile in OFF, and i record oryginal colors, and in Premiere i only add small contrast and saturation, and im very happy - speed and easy, no big noise.

Nobody is claiming that working with log is easier. What it is is more flexible in post.

If you like the look you get from an in-camera preset, you are using a traditional "video" workflow, which is easier, but you are limited in how far you can change from that look in post.

If you shoot log, you can change the image further in post, and that includes targeted changes such as pulling down only a bright window in the background, that you simply can't do in the same way with a "video" image.

I use more LUTs from TOPAZ like Kodak S-Log2, but i hate it. Blues looks horrible. i record in Odyssey 7Q in 4:2:2 Pro Res.

As I said in my previous post, if the LUT you use was designed for the S-Log2/S-Gamut from the F65 or F55, it will not look correct with the non-standard S-Log2 from the FS700

And i don't know i really don't like workflow with LUT.

I don't like red faces. If i see it in OFF profile camera i say to make up - please make --> make up, and girls look nice and white :3

And i don't know i'm studpied or what?
Maybe this is only marketing, and we make only more work and more and more...

No, it's not marketing. Marketing would be "The image looks great straight out of the camera. You don't need a log mode, because you'll never want to significantly change our fantastic looking images!" I think you'll find a manufacturer recently tried that approach, and it didn't work out well for them!

If you can create a LUT which you like, as Pythonman described a couple of posts back, and you load that into the Odyssey then apply it to every clip in post (as described in my tutorial videos on the CD website) it is a little bit more work, but if you do only that then it's not much more work. And you have the opportunity to tweak only the shots that you feel need it.

If the LUT you are using does not work well with the log from your camera, I don't think that's a good reason to say that log is a bad thing.

 

[pythonman]

Here is a link below to download a zip file containing the basic S-LOG2 LUTS I've made using the Datacolor SpyderCheckR24 card as a reference in Resolve 12. I've mainly concentrated on trying to make the colours accurate and have left the image fairly flat with just a little contrast, trying not to blow highlights or crush blacks as much as possible - allowing you to make further grading/tweaking as necessary.

It will be interesting to see if other peoples FS700/O7Q combos yield different colours, or whether they all produce the same.

Once you unzip the file you will find in the folder 4 CUBE LUTS - a neutral exposure version, and additional -1 and -2 stop versions. Also I included a contrasty REC709-style LUT in there too, same colouring, but more contrast. There's also a sub folder with the converted Odyssey 7Q LUTs that you can just copy straight to your 7Q SSD drive.

This is my first attempt so any feedback will be appreciated - specifically if you think the colours are more accurate than the original SLOG2 supplied LUTS.

https://www.btcloud.bt.com/?shareObj...f-bb24bcb33fd8

Once you open the above link then just click the 'Download' button at the top of the screen, rather than clicking on the file itself.

 

[jonbetzfilms]

Thanks for starting this conversation. I have been using the FS700/Odyssey 7Q setup for a while now and have been very frustrated by this issue.

Mitch, thanks for all you and your team do. I love your product and think you guys have done an amazing job, but for me I don't think the explanation that the current LUTs are just a "good starting point" holds up. I understand that they are based on Sony's color in the FS700 and their implementation of color in Slog-2 (which may be different than the colors on the F55 even using the same gamma curve), but a "good starting point" shouldn't require completely shifting hues by a significant amount for the footage to look like real life.

This is my first attempt so any feedback will be appreciated - specifically if you think the colours are more accurate than the original SLOG2 supplied LUTS.

Thank you for working on a solution to this problem. I have tried making LUTs many times for the FS700/7Q setup and I always come back to the point where although my LUT looks great on the shot I created it for, the Convergent Design supplied exposure compensation LUTs always look the best across a wide range of shooting conditions despite the pretty horrible skin tones and lack of anything blue.

I tried your -2 LUT on some footage I shot the other day. If possible, I would try using the CD-supplied LC709A LUTs and simply apply the color shift from your SpyderCheckr rather than starting from scratch. The gamma/contrast of your LUT seems off, and I do think that CD has done a good job of implementing the gamma correction in their LUT's. I may purchase one of these color cards to use on future shoots to protect agains these issues, and if I do I can try to post some custom LUT's myself.

Is it possible for you to post a shot that is properly exposed using one of CD's exposure compensation LUTs with the color checker in the frame (you mentioned an interview shot) so that we can play around with the correction in Resolve? Thanks for all the work and happy shooting.

[edit] Forgot to mention, yes your colors look better on first looks pythonman.

 

[pythonman]

Thanks for starting this conversation. I have been using the FS700/Odyssey 7Q setup for a while now and have been very frustrated by this issue.

Mitch, thanks for all you and your team do. I love your product and think you guys have done an amazing job, but for me I don't think the explanation that the current LUTs are just a "good starting point" holds up. I understand that they are based on Sony's color in the FS700 and their implementation of color in Slog-2 (which may be different than the colors on the F55 even using the same gamma curve), but a "good starting point" shouldn't require completely shifting hues by a significant amount for the footage to look like real life.



Thank you for working on a solution to this problem. I have tried making LUTs many times for the FS700/7Q setup and I always come back to the point where although my LUT looks great on the shot I created it for, the Convergent Design supplied exposure compensation LUTs always look the best across a wide range of shooting conditions despite the pretty horrible skin tones and lack of anything blue.

I tried your -2 LUT on some footage I shot the other day. If possible, I would try using the CD-supplied LC709A LUTs and simply apply the color shift from your SpyderCheckr rather than starting from scratch. The gamma/contrast of your LUT seems off, and I do think that CD has done a good job of implementing the gamma correction in their LUT's. I may purchase one of these color cards to use on future shoots to protect agains these issues, and if I do I can try to post some custom LUT's myself.

Is it possible for you to post a shot that is properly exposed using one of CD's exposure compensation LUTs with the color checker in the frame (you mentioned an interview shot) so that we can play around with the correction in Resolve? Thanks for all the work and happy shooting.

[edit] Forgot to mention, yes your colors look better on first looks pythonman.

Well thanks for trying them out, I appreciate it. I agree the gamma isn't a finished look - I deliberately made them all flat (apart from the one contrasty one) so that a more contrasty gamma could be added in post. I really just wanted the LUT to correct the colours only - not much else, allowing you to add a look thereafter. But I am no colourist, so I accept they are not perfect by any means. By the way I updated my post about an hour after first submitting it with slightly tweaked LUTs, so I don't know if you downloaded my earlier attempt. Either way here is a link to download a 4K TIFF screen grab file from the SLOG2 ProRes file that I used as a basis to colour in Resolve. The focus is not quite 100% spot on as I was shooting it myself of myself! It was shot in my house with the evening daylight coming through the side window and Velux roof window - no added artificial light added. It was starting to get dark so I had the camera set at 4000 ISO, shot at about 1 or possibly 1.5 stops over exposed. Camera set at 6000k white balance. By all means have a go - I'd love there to be better LUTs that provided more accurate colours - I agree with all your comments! If the CD provided LUTs had accurate colours I'd be more than happy - everything else about them is fine. Thanks again for spending time on this.

https://www.btcloud.bt.com/?shareObject=bc83cede-b487-74bc-8a11-e2b5511161d6

 

[jonbetzfilms]

Awesome thanks. I will try my hand at some LUT's today or tomorrow and post my results here.

 

[pythonman]

What an awesome idea you had about just correcting the colours of the CD SLOG2 LUTS. I just tried it - using that still frame I just sent a link to.

So in Premiere if you first apply the CD supplied SLOG2 LUT (either the -1 or -2 as appropriate) in the Basic Correction section of the Lumetri panel. Then in the Creative panel add this new colour-correcting LUT and bam - I think it works! This LUT does nothing but correct the colours:

https://www.btcloud.bt.com/?shareObject=026e8cbf-b91b-b819-cb90-54729de1e474

To confirm I took the still image, added the -1 CD SLOG2 LUT, then applied the Colour Match feature in Resolve (because the CD LUT effectively makes the clip REC709 gamma I selected REC709 as the source and target in the Resolve Colour Match settings). Let me know what you think.

EDIT: I think it's better but the blues have gone too bright. But overall it's definitely better. Needs more work, but happy to be making progress!

 

[pythonman]

OK - so I have incorporated the above into 2 new stand-alone LUTS. So this should provide the same gamma as the CD provided LUTs but with better colours. Here is the link:

https://www.btcloud.bt.com/?shareObject=a014c8d3-d5f0-5d79-a795-90194d9d0102

Again, appreciate any feedback. Thanks.