Recovering Highlights with Davinci Resolve
Ok so it's not really recovering highlights, cause if they're blown out, they're gone. It's more bringing near blown out highlights back into a useful visible range. A few people on bmcuser and reduser have been having problems with this, so I've put together this post. This method is probably the easiest I've found and works with all footage - DSLR, BMCC, Epic, Scarlet etc. It doesn't matter if it's raw or not.
Blackmagic Cinema Camera
This first example is from the Blackmagic Cinema Camera. This footage is shot during scene setup by bmcuser Note Suwanchote. You can ind the original bmcuser thread here.
First thing to do is to make sure your Color Space and Gamma are set to BMD Film and your 3D Output Lookup Table is set to Blackmagic Cinema Camera Film to Rec709. This ensures you're using all the available dynamic range, and nothing is crushed by grading Rec709 gamma encoded source material.
UPDATE: I'm finding that I'm actually getting better results by using the Arri Alexa LogC to Rec709 as the Output LUT. But test this yourself...
Next switch your colour wheels to Log mode. You're then able to use the Highlight master wheel to bring back the highlights. By default the High Range is set too high, it only really effects the brightest highlights. Drop it to 0.333 or there abouts depending on the image.
Here is the original image.
Lowering the highlights gives you the image below. The highlights are tinted pink because the blue channel has clipped. This is made more obvious by having the Highlight Recovery box ticked since its generating the missing highlight info from the un-clipped channels.
Notice how using the Highlight wheel also affects the foliage highlights. I actually dont mind this since it creates a more natural looking image compared to a more targeted selection that only lowers the highs in the sky/clouds. Normally I wouldn't lower the highs this much, so it won't usually be this obvious.
Desaturate the highlights using a serial node with a Luma qualification that only affects the highs. On this same node I've also bumped the contrast to create more definition in the clouds. I've also tinted the highs a fraction blue.
Epic / Scarlet
Here is another example using Epic footage. It's not as drastic as the example above, but usually Red footage looks pretty good if the ISO/FLUT is set properly.
It's exactly the same process as BMCC footage, although usually you dont need a node to desaturate the highs after you've taken them down.
The setup for this is RedColor3 / REDlog Film. And a film emulation LUT as the 3D Output Lookup Table.
And here is the finished shot.