Barrel distortion isn’t something we’ve dealt with since the days of the Phantom 1 with GoPro’s strapped to them. It’s ugly, unnatural looking, and especially apparent with a drone. It’s been good riddance until the Mavic 2 Pro.
Mavic 2 Pro
Free Distortion Correction
for FCPX, Premiere Pro, and Resolve
It turns out that DJI has been internally correcting for barrel distortion for their cameras. That’s worked well, but it seems this isn’t possible when recording in 10bit Dlog-M.
When the early versions of the Mavic 2 Pro came out, you could only shoot 10bit in HQ mode, which crops the sensor and hides most of the curved lines from the lens. I think DJI had to make a choice, give us 10bit, full FOV without distortion, or only have 10bit available in HQ mode. Since they pushed the 10bit color so hard in their marketing I think they had no choice. By the way, that 10bit color looks beautiful when graded.
What DJI says
I reached out to DJI, and while most of the responses were along the lines of “We’re looking into it.” I also got this :
“I am writing to provide an update to the report that we have created to our engineering team. The video captured in the DLOG-M and HLG color modes is uniformly encoded using 10bits H.265 for greater post-processing space. But 10bits video cannot complete distortion correction in the aircraft directly, it needs to be post-processed.”
It makes sense. I wish it weren’t true, but this is a tiny drone with a 1″ sensor. There’s a lot of heat and processing taking place so distortion correction isn’t possible. The good news is that I have something that will help.
It’s easy to think that fixing this in post is simple. The common suggestion is to to slap on de-fisheye plugin and dial it in until the curved horizon is straight. This sort of works, but barrel distortion doesn’t just affect the edges of the frame, it begins towards the center and then gradually worsens as it moves out. How far into the center of the frame should you adjust? This is a problem that an eye-balled correction can’t exactly fix.
If you’re like me then you understand that the lens has an exact, mathematical amount of distortion that doesn’t change, so a precise adjustment is possible. Once the correction is made, you never have to think about it again, just put it onto your clips with a click and you’re done.
After shooting some charts using the normal profile, I compared them to Dlog-M full and went to work. The result is an accurate distortion correction that I feel comfortable using on any film. If you’re editing with Premiere Pro or FCPX, you can combine the correction and the Dlog-M LUT into a preset and apply both with one click. Best of all, it’s a free.
distortion comparison between uncorrected and corrected
So here you go – accurate distortion correction for your Mavic 2 Pro for free. This works with Premiere Pro and Final Cut Pro X. Now go make something beautiful.