Apple Log Color Space Transform not working?

Hi!

I'm a total noob in Davinci (and actually in video editing) but I'm decided to learn Davinci for all its features, it's just amazing.

I'm recording with the Black Magic iOS app on my iPhone 15 Pro, codec h265, and color space Apple Log - HDR.

I'm trying to make it look "normal" in Davinci Resolve Studio 18.6 but I'm not able to. I'm using a node to transform from Rec2020 to Timeline (set to rec709).

Note: attaching a screenshot below that shows the huge difference between Final Cut Pro (left) and Davinci Resolve (right). What am I doing wrong?

Thanks for any help, really appreciate it!

I have also tried to set output gamma and colorspace manually but still the same, sadly. I'm not entirely sure what I'm doing wrong

I would suggest that as a new Resolve user you take advantage of the comprehensive set of free training materials provided by Blackmagic. Also don't forget the Resolve Reference Manual which you will find in the Help dropdown menu.
https://www.blackmagicdesign.com/uk/products/davinciresolve/training
Regarding color management you might find these useful.

Have you tried using a LUT rather than CST?
There are a few LUT’s for Apple Log available. Try a LUT and if that doesn’t make any difference it may be an issue with your footage

the other day I did a test with a friend and you get a ballpark by using the ACES -OFX, [apple in - rec709 out.]

Thank you everyone! Those videos were helpful but I'm still not getting it the same as in Final Cut.

This is what I've tried. Following the videos I've tried either to setup the color management in Project preferences or using the CST. Both gave same results but not same as Final Cut (attaching screenshots below)




I've also tried the suggestion of using ACES but not looking the same as Final cut either (attaching screenshot below)


Lastly I tried to use the official Apple LUT to convert from Apple Log to 709, still not looking like Final Cut. (attaching screenshot below)


So honestly I'm not sure what's going on. I'm going to record today a few more clips on Apple 422 LT (instead of H265) and see if this is still happening. Will report back!

what's going on, is that ANY method of going from camera raw or log to display referred (709) has a component of math and a component of "look" that every phone/camera manufacturer or software one decided to be.

what you're asking is akin to have two phones, from two different manufacturer, that take a picture and expect that the picture is identical. Is not going to happen BECAUSE if internal decisions taken by the manufacturer engineers in how to get the camera data out and present it to the display.

Final Cut, simply has its's own way to debayer/extract the log data from file and apply a technical LOOK to it. I'm NOT expecting to match unless you use an identical pipeline (like ACES).

so, if you are using an identical framework (ACES) and you are getting two different results, there is a error in the settings or the implementation.

If you are using it's own color management system, then it's whatever thet manufacturer decided to be. Dont stress over it, that's why we have still a jjob...lol....

You probably need to enable the Mac displays pref in Resolve as FCP is surely using the Apples ICC profile. With that and Apple’s LUT you should be closer.

Using the CST output should probably be set to 709a with a gamma of 2.4, OOTF, maybe maybe not. Definitely not 709 scene with OOTF checked.

Good Luck

Thanks everyone! Still not looking like Final Cut but maybe it's not correct either, I don't know. I will to just try to make it work on Davinci as I'm not planning on use Final cut anyway

Looking at your screenshots, you seem to be using a Rec2020 HDR project in Final Cut Pro and SDR project in Resolve. It would be fortuitous if they matched all things else aside. It's not clear why you want them to match but you would need to use similar settings in FCP as in Resolve if you want them to do so. Unless you are using a HDR monitor, you need to be working in SDR in FCP so you should create an SDR project in FCP. I don't know if FCP will interpret the footage as HDR but if it does you can use the Color Conform feature to convert it to SDR. This does a reasonable job.

Then use Resolve Color Management (RCM) at project level, choose automatic SDR and make sure you check Use Mac Display Color Profiles in the General Prefs (as Howard mentions). RCM makes things really easy. At that point you might hope that what you see in Resolve matches what you see in FCP (although again it is not clear why you want to do this) but more likely you will still have to do a bit of grading using the RGB parade scopes to get matching.

The bigger issue then is when you export your graded video from Resolve that it may not match what you see if you import this into FCP or view in Quicktime - but that is another story.

I just did an experiment with some H265 10-bit log footage from a Nikon camera and imported the same clip into FCP (Rec709 Library and Project) and Resolve (RCM automatic SDR setting). After normalising using the Nikon's own N-Log Lut (applied automatically in Resolve and manually in FCP) and no grading, the two are quite different with the FCP version a bit lighter and warmer than the Resolve version. As Walter says, there is no expectation that they should match, as each program handles the same clip differently even using the same normalising lut. I don't have any iPhone log footage but the basic principle should still apply - there is no expectation of matching,

So basically you are wasting your time trying to match the original log footage in the two apps when such matching is not expected. More importantly, if you grade the footage in one of the apps, export that and import it into the other, the expectation is that they should match. In general you are only going to grade in one app and perhaps export that for editing or finishing in another but you should generally not need to grade in two different apps. Given that you are not going to use FCP in any case, I would suggest you move on and learn Resolve if that is your intention without worrying about FCP.

All that said, there is a well-known problem with exporting Rec709 video from Resolve and having it match in FCP and Quicktime but that is another story again. You can climb that hill when you come to it.

All that said, there is a well-known problem with exporting Rec709 video from Resolve and having it match in FCP and Quicktime but that is another story again. You can climb that hill when you come to it.

That's a very big hill.

Yeah, let's have a party when that thread is reaching 20 pages

Yeah, let's have a party when that thread is reaching 20 pages

I hate that thread, but I can't help reading the updates to it, lol.

Thanks everyone once again!

I searched and even created a new project on FCP but I couldn't find any option to do SDR.

Anyway, I guess because I'm ignorant I just assumed if I'm recording in Apple ProRes with Apple Log and I apply a Rec709 conversion then both should match and that would give me a true 100% scientific conversion.

I'm going to take all your advice and move on with Resolve, I don't know at this point what's the "scientific 100% correct conversion", before I start learning a bit of color grading I just wanted to convert the footage 100% correctly to Rec709, hopefully, Davinci is the one that's doing it "correctly" (if you can say so?)

Thanks everyone once again!

I searched and even created a new project on FCP but I couldn't find any option to do SDR.

Anyway, I guess because I'm ignorant I just assumed if I'm recording in Apple ProRes with Apple Log and I apply a Rec709 conversion then both should match and that would give me a true 100% scientific conversion.

I'm going to take all your advice and move on with Resolve, I don't know at this point what's the "scientific 100% correct conversion", before I start learning a bit of color grading I just wanted to convert the footage 100% correctly to Rec709, hopefully, Davinci is the one that's doing it "correctly" (if you can say so?)

When you create a new library in FCP, it is automatically Standard Gamut SDR and any project you create in that library will be SDR Rec709. You have to manually change it to Wide Gamut if you want Rec2020 HDR (PQ or HLG) - the little blue button that says Modify on the right side of the screen under Library Properties. Not sure how you managed to create a Rec2020 project in FCP without actually deciding to do that.

There is no absolute correct conversion to Rec709. Each app will give a different starting point and you grade from there. Just one thing - Resolve is a much more complex app to work in than FCP as there are far more choices and potential pitfalls. FCP is far easier to work in for a beginner in my opinion, particularly if you are shooting and grading iPhone footage as it should just work out of the box. The great thing about Resolve is that BMD have provided some excellent free training which you really should take advantage of if you are going to learn Resolve. Best of luck on your journey.