Cinelog-C for DaVinci Resolve - Quick Start guide
Part 2 - Import, conform, Scopes, White Balance and Exposure
Before we create our first transcode job and render our raw images to ProRes or DNxHD videos in Cinelog-C colorspace we need to make a few adjustments, check White Balance and Exposure.
Double click on the preset we created in part 1 to open the Media manager screen of DaVinci Resolve. This is where we will import our footage.
On the left of the screen are the drives Resolve can currently access. If you cannot see the drive that contains your footage you must add it to Resolve.
To add a Storage Volume (disk) or location (i.e. a folder containing your DNG images), go to the main/top menu and click on DaVinci Resolve then select Preferences to open the Media Storage panel.
Click on the Media Storage tab if it's not already selected and add a new hard drive or location using the + button.
The Media Pool
Navigate to where you images are stored and select the images you want to transcode. You can select a single image sequence by selecting a single folder or a group of folders.
With the images or folders selected right + click and choose Add to Media Pool - this could also be Add Folder(s) to Media Pool or Add File(s) to Media Pool depending on the content selected.
Continue to locate and add more footage to the Media Pool if required. You can sort Media Pool content into easier to manage folders by selection the + symbol in the Media Pool pane (left of the screen) then dragging and dropping the files into the newly created sub folder(s).
Depending on the files contained in each folder, the Media Pool may show DNG image sequences, audio files (if any were recorded) and possibly proxy files, proxy video files and stills (jpeg, tiff etc). To avoid confusion you may wish to remove these non-raw items from the Media Pool or move them to a sub folder.
We now move to the EDIT screen (one of the 4 main options at the bottom of the Resolve screen)
The EDIT screen is where we will add our footage to a new Timeline. This section is also where you can edit footage, create transitions, mix audio and more but for this job we only use it to create a timeline to hold our footage.
A new Timeline must be created to hold the footage. The default timeline cannot have footage added to it.
To create a new timeline, navigate to the top menu. Select File and choose New Timeline.
This will open a small panel where we can name the timeline and adjust where timecode starts (no adjustment to timecode is made in this example).
The Empty Timeline tickbox is selected by default.
Note: Some footage (i.e. MLV) may be out of 'as shot' order. Creating an empty timeline will allow you to manual drag and drop individual shots to the timeline in the order you choose. If your footage appears in the media panel in sequential/as shot order you can untick this box and click the Create New Timeline button - this will then populate the timeline with all the footage from the selected Media Pool folder. If you do this you can skip the next paragraph about populating the timeline manually.
Populate the Timeline manually
If your footage is not shown in the correct order you should leave the Empty Timeline box ticked then click Create New Timeline. This will create an empty timeline with a single video track and a single audio track, onto which you can drag & drop each shot - alternatively you can right + click each clip and choose Append to Timeline.
We are now finished in the EDIT screen and will go to the COLOR screen to make a few adjustments.
The LOOK of Cinelog-C is NOT Important!
One thing you may have noticed between the MEDIA screen and the EDIT screen (after creating your new Timeline) is that our shots no longer appear flat and washed out in the preview window. This is because the image showing in the preview/monitor window is in REC709 colorspace. It is transformed from BMD Film to Cinelog-C and from Cinelog-C to REC709 - thanks to the Luts we added when setting up the project in part 1.
You will also notice the timeline itself still looks flat - this is Cinelog-C and it will be how your ProRes or DNxHD log masters appear when rendered.
It does not matter if you don't like the look of Cinelog-C!
I don't think Cinelog-C looks good either, in the same way as I don't like the look of Log-C, Canon Log, S-Log or other log profiles.
The look of Cinelog-C is not important - It is not a look - Cinelog-C looks like it does for purely technical reasons.
You are looking at the image with it's color gamut and dynamic range, heavily compressed. We un-compress this later (during editing or color grading) using a LUT such as the Cinelog-C to Cinelog REC709 lut we are now viewing through or a Cinelog Film Look LUT.
Before we render our Log Masters we might need to fine-tune the White Balance and Exposure offset of our shots. These will be permanently baked into the video file so it is the best time to get it right.
Unlike some raw apps, DaVinci Resolve does not have a one-click Auto White balance solution (automatic white balance is not always a good idea anyway), so we must adjust the color temperature and tint offset manually.
This is not as difficult as it appears but there are several different methods we could employ plus various gotchas (mainly due to embedded DNG metadata) that can make it much more difficult - especially when it comes to balancing Magic Lantern Raw Video.
We will take a deeper look at white balance in a separate guide.
The following White Balance section assumes your footage does have the correct metadata - specifically, correctly populated color matrix tags.
In Part 1 we selected project-wide settings that affect the Camera Raw panel. These settings tell DaVinci Resolve to debayer every shot to BMD Film colorspace with Highlight Recovery enabled.
It also defaults to As Shot White Balance because ideally, you will have carefully balanced your shots (using a grey card or the white balance side of a Colorchecker Passport or similar) in-camera before hitting record.
Warning! - Shooting Raw can tempt you into lazy shooting practices by deferring white balance setting and correction to post production - this can add significant time to your workflow and cause you or a colorist/editor major headaches!
Tip: Don't be lazy shooter - Try to get it right IN CAMERA!
Fine-tuning White Balance using the Camera Raw pane
Of course, setting up what appears to be a good White Balance in-camera is no guarantee that it will be perfect but now is the time to fine-tune it so lets do that - begin by changing the Decode Using to Clip.
If you look at the image opposite you will note the 2 numbers I have highlighted with a red box. This is the Color Temperature and the Tint (or magenta vs green bias) that were set in-camera and adjusted (by Resolve) so that the white point is correct for BMD Film Colorspace.
You will also note that the same settings in the Clip column are greyed out and cannot be changed - this is because Resolve is currently using the As Shot White Balance.
We need to change the White balance so, as it's a Daylight shot, lets choose Daylight from the dropdown menu.
Ok, this has unlocked the White Balance and Tint controls in the Clip column but it has also tinted our image green (see images below). Not really what we wanted!
The reason for this is simple. The Resolve preset for Daylight White Balance has a Tint offset of 10.00 - it has changed the Tint offset for our As Shot value of 88.08 to 10.00, a very big (relative) shift towards green and it has also increased the Color Temperature from 5167k to 5500k (Degrees Kelvin) .Putting these back to the values shown in the Camera column will get us back to As Shot White Balance so let's do that.
You will notice the White Balance selector now says Custom, the green tint is removed and we can still edit the Color Temp and Tint.
Magic Lantern Raw Video Metadata - Problems
Before we move on to tweaking the Color Temp and Tint I should mention something important related specifically to Magic Lantern Raw Video.
You may have read the White balance section above and thought "I did set white balance correctly in-camera but my Magic Lantern Raw Videos always have a tint / look wrong in Resolve"! - If so, congratulations!
You have just discovered something quite important about Magic Lantern Raw Video - MLV Metadata is generally incorrect or incomplete. This is not necessarily the fault of the Magic Lantern Developers but is something most developers of MLV processing/extracting apps have not yet addressed.
The issue can be fixed using ExifTool! We will describe how in another article asap!
White Balance - using the Scopes
To assess the white balance of the shot we could just use our eyes and monitor but both do not give you a true picture of what the actual video signal is doing.
You may have 20:20 vision and a calibrated monitor but, for this technical adjustment, it is always best to use Scopes!
The various Scopes in Resolve look at the image in a completely different way than our eyes and enable you to spot problems and fine tune your adjustments with much finer accuracy. To access the Scopes panel navigate to the Main Menu and select View > Video Scopes > On/Off.
About the Scopes
The Scopes panel defaults to show 4 different Scopes - Waveform, RGB Parade, Vectorscope and Histogram. It will also default to 16x9 aspect ratio - This can be changed to 4x3 (as in the image above) using the settings at the top of the panel. Each of the panels can be configured to show a different scope using the dropdown menus and you can show 1, 2 or 4 scopes at once. The panel itself can be scaled by mousing over a corner, then click+drag to the desired size.
I deliberately left this change to the Project Setting Panel until now to demonstrate how the Lookup Tables panel can be configured to work with Scopes, independently of the monitor and video output. You can update the Project Preset we created in part 1 to always use this setup if you wish.
Scope and Viewer LUT
You may have noticed when looking at the Scopes for the first time that the signal levels look odd/weak.
This is because the Scopes are actually looking at the Timeline signal and the Timeline is Cinelog-C.
This begins to reveal more of the power behind Resolve's LUT panel - you can choose different LUTs for different purposes in different areas independently.
To better judge the White Balance and exposure on the Scopes we need to tell the Scopes to look at the REC709 signal. We do this by changing a setting in the main LUT panel (as shown opposite).
Open the Project Settings Panel and navigate to the Lookup tables panel and, in the slot named 3D Scopes Lookup Table, select Use Video Monitor Selection (this tells the Scopes to look at the monitor output and we have already assigned the Monitor to use the Cinelog-C to Cinelog REC709 LUT).
If you are using an external monitor it will still be showing the REC709 signal, but if you are only able to view the internal Resolve monitor it may revert to show the Cinelog-C signal - We will correct this by changing it's settings to Use Video Monitor Selection too.
Click Apply and close the Project Settings Panel.
White Balance - continued
Now that the Scopes are analyzing the REC709 signal we can better judge any White balance and Exposure tweaks that may be needed.
Judging by the scopes we seem to have a reasonably good exposure but I can't be sure about the white balance because the Vectorscope shows a slight magenta bias, plus the image looks slightly too cool.
There are areas of the shot that I know should be neutral or white (i.e. the signs) but I know another of the shots that was filmed minutes later, and has a much large area of white that can be analyzed better.
This is a perfect example of why shooting a few frames of a grey card or MacBeth colorchart would have saved a lot of time and be more accurate!
WARNING: Saturation problems (OSX)
Since the introduction of DaVinci Resolve 12, Blackmagic have, by default, enabled a setting that uses the Mac color profile for Resolve viewers. This setting can lead to over-saturation and/or color shifts when viewing the Resolve viewer on an un-calibrated monitor. If you experience this try switching this setting OFF. (Color Management settings)
This shot has a large area of white and the magenta bias is more pronounced - We can zone in and isolate the white area with Power Window for a better look.
I won't go into great detail here about Power Windows as it's a big subject but for this task we will use the freehand shape as it allows us to select a non-uniform area by creating anchor points.
Select the Power Window panel and Shape as shown in the image opposite. Then using your mouse (on the viewer window), click on the image to create the first anchor point. Repeat until you have created a shape that encloses the white area. the final anchor point should be the same as the first.
You will see the node labeled 01 now looks grey with a small patch but we can still see the whole image (and the Scopes will see the whole image too) so we must isolate the shape area - we do this by clicking the wand icon (highlighted with a red box in the image opposite).
Now we can see there is indeed a magenta tint to something that should be white.
If we now open the Scopes panel and look at the Vectorscope, the magenta shift is noticeable. you may want to adjust the Scope settings (bottom right button) for a better look.
On a Vectorscope pure white would be in the absolute center and usually, as white has no color, it would not show at all. In reality and especially when looking at a patch of an unknown white, it is typical to see something.
Tip: If you didn't know already, a Vectorscope is for viewing color.
Now lets fix this shot
Using only the Color Temp and Tint controls in the Camera Raw Panel and still looking at the Vectorscope, move the white dot as close to the center of the Vectorscope as you can as shown opposite.
Then click on the wand icon again to reveal the full image.
The images below show the before and after of the white balance adjustment. The difference is actually very noticeable and you can see now just how much magenta tint there was.
We no longer need the Power Window so we can delete it. To do this, navigate to the main menu and select Color > Reset Selected Node Grade
As this shot was made at the same time as the other shots in our timeline with the same camera/settings we can be confident that the white balance correction we just made will work for those too so lets copy the settings from this shot to the rest of the timeline. To do this we don't need to retype the Color Temp and Tint for every shot.
Copying the White Balance Settings to the other shots
While holding down the Control key on your keyboard, click on each of the shots on the timeline (they will turn orange) then click on the icon (shown in the red box) to Apply settings to all selected clips.
The correction is now copied to the other clips. Now is a good time to check each shot just in case they need further fine tuning.
You can also adjust the exposure offset for each shot (if needed) using Exposure in the Camera Raw panel but we suggest being restrained from large adjustments unless absolutely necessary, especially if you are not viewing though a calibrated broadcast monitor.
Exposure is a whole other subject that we will cover in another guide later.
That concludes Part 2 of the User Guide - in part 3 we will set up our actual render job and make our Cinelog-C Log masters!