Blackmagic Forum

I am trying to color correct automatically D-Log M footage using CST but I have a problem: the clips look weird very saturated/contrasty.

I work on a Mas so used the following settings for the project:

Color Management:
Color Science DaVinci YRGB
Timeline Color Space Rec.709-A
Output Color Space Same as timeline

I recorder a clip in Regular color for control and one in D-Log M and brought them into the timeline. Then I applied a CST effect to the D-Log M clip with these settings:
Input Color Space DJI D-Gamut
Input Gamma DJI D-Log
Output Color Space Rec.709
Output Gamma Rec.709 (but tried also with similar results with Rec.709-A

You can see the two clip images.

I tried also with a Color Managed project but it's the same result. Where do I do wrong?

Hey Mario,

D-Log M is not the same as D-Log. The M version is more of a customized curve that makes the footage quasi log. Optimizing dynamic range without losing too much image quality due to the typical 8bit h264 encoding the cheaper drones have.

Because it isn't a real log encoding there is no support for it inside Resolve. The idea is more or less to treat it as a Rec.709 clip and grade it as is, meaning you'd increase saturation and apply contrast the way you see fit.

Alternatively you could use LUTs or other conversions others have made. But IMO those aren't that much more practical than rolling your own unless you need some form of technical transform to linearize your material for compositing. But even then I have my doubts whether all D-Log M flavors per camera are the same.

Oh okay now I understand why it was not looking right. I have a Mini 3 Pro and that one have D-Cinelike now the Action 4 has D-Log M.

Well I will probably shoot with a Regular profile with the DJI Action 4, I never do any colour grading anyway.

Thank you for clarifying.

The odd thing is that GoPro clips shot with Flat profile (not log) are color corrected perfectly with Color managed.

If you need to convert D-Log M to Rec709, there is a LUT on the DJI website. Do a google for "DJI Mavic 3 D-Log M or DJI Air 3 D-Dlog M to Rec709" (its the same LUT).

Good Luck!

VMFXBV wrote:If you need to convert D-Log M to Rec709, there is a LUT on the DJI website. Do a google for "DJI Mavic 3 D-Log M or DJI Air 3 D-Dlog M to Rec709" (its the same LUT).

Good Luck!

Thank you I'm aware of that, I was hoping for a color managed workflow that didnt require to apply LUTs.

But that's just a flat camera profile really. Not actually log encoded, so I don't know what you expect Resolve to do for you.

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rNeil H wrote:But that's just a flat camera profile really. Not actually log encoded, so I don't know what you expect Resolve to do for you.

GoPro flat clips imported into a color managed project are colour corrected automatically. Also I didnt complain.

Mario69Rossi wrote:

rNeil H wrote:But that's just a flat camera profile really. Not actually log encoded, so I don't know what you expect Resolve to do for you.

GoPro flat clips imported into a color managed project are colour corrected automatically. Also I didnt complain.

Is this more of an issue with automation or a technical transformation correctness problem?

If your project consists of mostly DLog-M clips then you can add the LUT in custom color managed projects. Its at the bottom of the color management page, under the Output Lookup Tables section. Then every clip will have that at the end of the chain.

VMFXBV wrote:Is this more of an issue with automation or a technical transformation correctness problem?

If your project consists of mostly DLog-M clips then you can add the LUT in custom color managed projects. Its at the bottom of the color management page, under the Output Lookup Tables section. Then every clip will have that at the end of the chain.

I tried to look into setting the LUT into the Color Management of the project under Output lookup table but I cant see a way to disable the LUT setting of the non-D-Log M clips.

I would like to find a fast workflow that allow me to import D-Log M clips into a project and have a LUT applied somewhat automatically. Selecting the clips and group them in the Color Page isnt the best solution because the same clips are used in different timelines and I would like to avoid applying the lut to the D-Log M clips in each timeline.

I guess the a solution is to apply the LUT in the media page but I wish there was a was to apply the LUT in the media page to all the D-Log M clips and have it showing up as node in the Color page so that if I could create nodes before the LUT.

Mario69Rossi wrote:
I tried to look into setting the LUT into the Color Management of the project under Output lookup table but I cant see a way to disable the LUT setting of the non-D-Log M clips.

In the color page if you right click the clip that isn't D-Log M you can select bypass color management and then work as if you work in DaVinci YRGB, manually.

Unfortunately that's the limitation with non-raw clips. The ones that are properly converted have metadata to do so I guess but not every clip will have it.

No color managed doesnt work in D-Log M so that's the problem. As I said I tried with Davinci YRGB and setting the LUT into the Color Management of the project under Output lookup table That would work if I could see a way to disable the LUT setting of the non-D-Log M clips.

Mario69Rossi wrote:No color managed doesnt work in D-Log M so that's the problem. As I said I tried with Davinci YRGB and setting the LUT into the Color Management of the project under Output lookup table That would work if I could see a way to disable the LUT setting of the non-D-Log M clips.

Its weird, bypassing color management should in theory bypass that LUT as well. Weird that it doesn't.

Other solution for you would be:

- DaVinciYRGB and use Groups. Basically select your D-Log M clips in the color page and group them. After you group them on the node section where those tiny dots are for Clip and Timeline a new group of dots will appear with Group Pre Clip and Group Post Clip. Use that LUT in the Group Post Clip and you will have it selected for all your DLog clips only. Do the same for the other clips that are not D-Log if you want to use another LUT or a CST.

- DaVinciYRGB Color Managed and set your color management for every other clip that isn't D-Log (like RAW and etc) and use the same groups as above for the D-Log clips. With the bypass color management selected for these clips of course.

Not exactly automated but oh well.

Again, that isn't a log clip. It's straight Rec.709 with flat camera settings. It just "looks log-ish". You can duplicate it by manually changing the settings in the camera yourself.

So it's not something that automated processing can read.

You can either import or create a LUT that you then apply to all such clips. Or you can grade a few, save that as a Still, and apply to any such clips.

Automated processing doesn't work with camera profile settings.

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rNeil H wrote:Again, that isn't a log clip. It's straight Rec.709 with flat camera settings. It just "looks log-ish". You can duplicate it by manually changing the settings in the camera yourself.

So it's not something that automated processing can read.

You can either import or create a LUT that you then apply to all such clips. Or you can grade a few, save that as a Still, and apply to any such clips.

Automated processing doesn't work with camera profile settings.

I think we established this a long time ago, if you dont have anything to add to the conversation, your comment is not required. If you had read carefully I do have a LUT.

Again I tell you that gopro flat profile is not a log but it is color corrected automatically in color managed project. Now I get it that the same correction doesnt apply to D-Log M clips so I'm trying to find a quick workflow to apply the LUT to the D-Log M for the color correction that allow me to use the clips in multple timelines without having to apply the LUT time and time again and preferably that the LUT is applied as last node instead than apply the LUT at the media page level.

VMFXBV wrote:
- DaVinciYRGB and use Groups. Basically select your D-Log M clips in the color page and group them. After you group them on the node section where those tiny dots are for Clip and Timeline a new group of dots will appear with Group Pre Clip and Group Post Clip. Use that LUT in the Group Post Clip and you will have it selected for all your DLog clips only. Do the same for the other clips that are not D-Log if you want to use another LUT or a CST.

What I wanted to avoid is the creation or the groups for each timeline in the project. Even remote grades doesnt seems to be what I want.

Hey Mario,

I think your approach is technically flawed. If you only have footage that can not and don't need to be colormanaged there is no point in using it.

Mario69Rossi wrote:Again I tell you that gopro flat profile is not a log but it is color corrected automatically in color managed project.

I believe what you are seeing is simply the effect of indeterministic media being treated as D-Log because you set your project managed input color space as that. It just so happens that the Go Pro flat profile is less contrasty than the DLogM footage making you thing that it gets treated "properly" but you are simply basing that opinion on what you see.

If we would fully negate all principles of colormanagement you could for that same case try to find a colorspace that responds nicely for your DLogM footage and call it a day. None of it would make sense but you'd be happy.

The proper approach however would be to return to DaVinciYRGB and create groups for DLogM and GoProFlat. Then on the group post-clip level node tree you'd create your desired look for each camera. It doesn't matter how, LUTs, 3way wheels etc. Once that's done you continue grading on the clip level itself for individual adjustments. Pretty much what VMFXBV already suggested.

Using groups isn't even limited to a single timeline. It spans through your entire project so you can make global adjustments for everything in that group and only have a single one per camera.

shebbe wrote:Using groups isn't even limited to a single timeline. It spans through your entire project so you can make global adjustments for everything in that group and only have a single one per camera.

Your suggested workflow could work very well for me but I dont see a way to make a group to the entire project at least not the way I would have hoped: create a group apply post clip the lut to the group and then use the clips in several timelines but instead the way it seems to work is every new timeline you need to select the clips and assign them to the respective groups. It would have been a much better workflow to be able to create a group in the media pool and assign there already the group post-clip correction. That way every time you use one of the clips in a new timeline you do not need to assign them to a group.

But I guess it is what it is and it's either this 2 step system (create the group then apply the LUT and then for each timeline assign the respective clips to the related groups.

shebbe wrote:It just so happens that the Go Pro flat profile is less contrasty than the DLogM footage making you thing that it gets treated "properly" but you are simply basing that opinion on what you see.

Sorry I thought it was DR having a profile for GoPro so it's just a lucky coincidence that GoPro Flat imported into a color managed profile looked exactly as GoPro Color. Sorry I thought it was DR having a profile for GoPro.

Mario69Rossi wrote:It would have been a much better workflow to be able to create a group in the media pool and assign there already the group post-clip correction. That way every time you use one of the clips in a new timeline you do not need to assign them to a group.

For projects with a lot of timelines that could be a practical approach. But mechanically it would mean that all the media is hardwired to those groups which you may not want for every timeline depending on the project. You can always suggest a feature in the Feature Request section on the Resolve forum though.

What you can do for now however is go to your Media Pool page. Select all your DJI footage, and right click flag them with any color flag. This flag will appear on all timelines on those clips also in the Color Page.

While on the color page, on the top left click on the arrow next to [Clips] and filter the view by the flag color you chose. Now your Color Page only shows the clips flagged and you can select them all to assign them to the right group.

Then after that go to the filter again and select "no flag" which will filter the opposite.
Then repeat the group assignment.

If you'd have even more cameras or other material you could also use more flagging of course and filter accordingly.

If you don't like the flags method because it visually adds flags on the clips, you can also look into Keywords. On the Media Pool make sure your view is set to list and rightclick the columns to add the column Keyword. Add your keyword to one of the DJI clips. That keyword will appear where your smartbins are. You can drag the remaining DJI clips onto that keyword. Then repeat the same for GoPro.

Now you can filter via Keyword on the Color Page.

Good luck!

Yes I do use colour flags already as I use three different cameras and it helps me editing a bit faster and thought of using it to assign the clips to the right group. Thank you for your suggestions.

Is there a LUT for plain old D-Log or doesn't that even exist ? I had to color some drone footage that I was told was shot in D-Log and I couldn't find a LUT that worked or was just called D-Log. I tried a number of things that had D-log as part of the name and they were all over the place. None seemed correct to me. I can't remember what I ended up doing but it might have been that an ordinary Slog3 > 709 LUT got me surprisingly the closest . I'm kind of hazy though . I'll check it l;ater .

Leonardo Levy wrote:Is there a LUT for plain old D-Log or doesn't that even exist ? I had to color some drone footage that I was told was shot in D-Log and I couldn't find a LUT that worked or was just called D-Log. I tried a number of things that had D-log as part of the name and they were all over the place. None seemed correct to me. I can't remember what I ended up doing but it might have been that an ordinary Slog3 > 709 LUT got me surprisingly the closest . I'm kind of hazy though . I'll check it l;ater .

You can download the LUT from DJI website.

Thanks, I did find it and oddly discovered that footage that was supposedly shot in D-Log looked better to me with an SLog3 LUT applied.

I also shoot in D-Log M and if I only need to deliver SDR then I use LUTs provided by DJI and that works well as starting point for grade.

However, I sometimes need to create HDR video from those sources and here things start to be different. For my old Mavic 2 Pro DJI D-Log gamut/DJI log gamma work ok as a start point but for new Osmo Pocket 3 usually D-Log Gamut/HLG gamma work better. Since CST is non-destructive you can always fix imperfections.

Best but more time consuming - as it was already suggested here - is to apply manual contrast and saturation.