BMPCC matching footage with Ursa Mini

Here is the BMPCC note it is orange

BMPCC.jpg (978.67 KiB) Viewed 2827 times

Hi,
I have the BMPCC 4K camera and an Ursa Min 4.6k. I recently shot a video with both cameras. The subject had a red shirt on. BMPCC the shirt was definitely orange and the URSA was definitely red/pink. No amount of color correction, temp, tint or anything could get them even close. BMPCC orange, Ursa red. Anyone have any ideas how to fix this in post or why this would happen?

You should probably post this in the Davinci Resolve forum - you'll get help grading them to look similar.

Short answer, there's many reasons your images look different, here's a few:

Different Sensors (different cameras)
Different WB settings in the camera
Different lenses
Different filtration (I.E. glass in front of lens)
Different sensitivities to IR wavelength light (infra red pollution)

You really need to read up on my points above. There's lots of threads on the board discussing all of these points, and more. But in a nut shell, the sensors in the BMPC 4K and UM4.6k are built by different manufacturers, so you'll need to do more work to get them to match. The Cinema Camera, Pocket Camera and UM4.6k all use sensors from the same manufacturer and are the easiest to match. The BMPC4K, URSA and UM4K have the same sensors, so they are easier to match.

When you get to post you want the greatest quantity of available information/bitrate to correct. If you're using ProRes/DNxHD then your WB is baked in, so make sure your setup is as accurate as possible (WB, exposure, filtration etc) try to use the best quality. RAW is best.

As Tristan explained very clearly, what you are seeing is completely normal. Although both cameras are made by Blackmagic Design, they use vastly different sensors and each of the two records in a unique gamma and color space. It will take careful color grading to make them render particular hues and saturations as similar colors. Working in either ACES or Resolve Color Management (both are well covered in the Resolve manual) will help as a starting point. Beyond getting the color temp and tint to match, you'll then need to tweak the "hue v hue" and "hue v sat" curves (covered in the Resolve manual). The match can be made more accurate by shooting a reference chart like the DSC Labs One Shot because it has large color chips specifically designed to be easily distinguished on the vectorscope. Resolve has an "auto" matching feature compatible with this chart (and others), but personally I find that "auto" is more trouble than it's worth and recommend working manually instead.

The URSA Mini 4.6k and Pro had a metadata error when recording ProRes below 444 resulting in wrong interpreted colors (mainly visible in the reds: too magenta) in editing software like Premiere Pro. This bug has been fixed with firmware 4.4 and later.
Anyway, Resolve always has interpreted those ProRes colors correctly.

What I can say from your sample images is that you should post lower the blue channel gamma (e.g. with curves tool) on the UM46k footage - it has raised blues compared to the BMPCC.

Quick and dirty adjustment in Photoshop with Hue/Sat (Reds, Yellows and Blues) and Curves:

Why does the footage look so clipped? Did you record in film log or in Rec709? Or is it a LUT?

Quick and dirty adjustment in Photoshop with Hue/Sat (Reds, Yellows and Blues) and Curves:

Nice work Robert. For a 'quick and dirty' you're 95% of the way there.

I too noticed it looked very clipped. Over exposed or a LUT?