Blackmagic Forum

Hi,

I am trying to shoot videos for my YT channel with both my OG BMPCC and an iPhone 15 Pro Max simultaneously.
Until now, I would shoot them with the pocket vertically 1080x1920 and now I intend to use the iPhone 15's 4K to have a horizontal version of the same video.

However, I can't match them even though I record raw (pocket) and log (iPhone through blackmagic app) on both devices and make the proper color transform changes (or so I think) in Davinci.

BMPCC - three nodes.

First node : white balance, exposure, adjustments, etc (this, I won't touch yet)

Second node: Color space transform

input color space: blackmagic design film gen 1
input gamma: blackmagic design film
output color space: ARRI Wide gamut 3
output gamma: Arri logC3

Third node: Lut (Arri Alexa LogC to Rec709

iPhone 15 Pro Max - two nodes.

First node : white balance, exposure, adjustments, etc (this, I won't touch yet)

Second node: Color space transform

input color space: Rec2020
input gamma: Apple Log
output color space: Rec709
output gamma: Gamma 2.4

Then, ideally, I would use a color chart to match colors in the first node, but since I don't have one I use a white A4 paper on which I apply Davinci's white balance tool. I tried; they don't even look close.
Has anybody managed to match them or can somebody help me out?

Thanks in advance.

I've never attempted to match footage from those two cameras (which are extremely different in so many ways), but if it were me I'd dispense with the CSTs and use Resolve Color Management, which is designed to help you match footage from different cameras.

In the Color Management tab of the project settings, set the color science to DaVinci YRGB Color Managed. Set the color processing mode to DaVinci Wide Gamut Intermediate (which will give you more latitude for grading the BMPCC footage, assuming you shot it in log or in raw), and set the output color space to whatever you're delivering to. For youtube I think you'd want to choose Rec709 gamma 2.2 as the output space since most computer monitors are set to gamma 2.2; I assume the same is true of phones and tablets but have never looked into it.

Oh, I will definitely try that out.

Yes, I'm aware both cameras can't be compared -- not to speak of the lens I use with the pocket, which has its own particular flavor, the warm and soft Meteor 5-1 -- but I had heard so many good things about iPhone's log paired with Blackmagic's app that I thought they could end up looking reasonably close.

Thank you, Brad. I'll let you know how it goes!

Brad Hurley wrote:I'd dispense with the CSTs and use Resolve Color Management, which is designed to help you match footage from different cameras.

To be strictly clear, it isn't designed to match cameras. Rather to generalize display rendering and manage color in a slightly more automated fashion. You can achieve the exact same results with using CSTs in a manual setup.

@Roberto, The main aspect to matching cameras is to use the same display rendering, which you automatically do if you use RCM, ACES, or manual setups. The basic principle of 'modern' managed grading setups is shoot in log or raw -> convert to a log grading space of choice -> render to display with a single transform. From what you've explained you're using Arri's 'classic' rendering on the OG BMPCC and DaVinci on the iPhone.

For both camera's you'd want for example to convert to DaVinci Wide Gamut / DaVinci Intermediate, then grade, then a CST from DWG/I to Rec.709. Or convert both to AWG3/LogC3 and then use ARRI's rendering instead. (You could even grade in DWG/I and convert to AWG3/LogC3 at the end to then apply the ARRI LUT but I'd focus on simplicity first.)

When using manual management the most efficient way is to use groups where the pre-clip group node tree would be just the CST to convert to the grading space. The group post-clip node tree where you convert to Rec.709. Doing it on the timeline is not practical unless grading your footage is the only thing you do. Otherwise you apply it to graphics/text and other elements that shouldn't be part of it.

Color Managed does the same tranformations but 'hidden' with input conversion before the entire node tree and out all the way after timeline node tree. So it frees up your group node trees for other purposes which may be preferential. But you won't be able to do any operations before input conversion or after display conversion which in some cases you may actually want.

Try both and see which you prefer. When using manual management make sure you still set your timeline in the project settings to DWG/I if that's the grading space you chose. This will make sure that conversions are done as intended and HDR wheels work as they should without manually setting them to the correct space.


Once everything is solidly set up managment wise, all that's left to deal with is plain sensor, lens, encoding quality differences that you have to deal with. That only comes with practice and doing it a lot. And some things will never match fully ofcourse. The main goal should be to make them feel like they belong in the same world, not match 1:1.

Hi, shebbe,

Thanks for your elaborate answer. I'll read it carefully; a lot to process for this color-grading novice!

Brad Hurley wrote:I've never attempted to match footage from those two cameras (which are extremely different in so many ways), but if it were me I'd dispense with the CSTs and use Resolve Color Management, which is designed to help you match footage from different cameras.

In the Color Management tab of the project settings, set the color science to DaVinci YRGB Color Managed. Set the color processing mode to DaVinci Wide Gamut Intermediate (which will give you more latitude for grading the BMPCC footage, assuming you shot it in log or in raw), and set the output color space to whatever you're delivering to. For youtube I think you'd want to choose Rec709 gamma 2.2 as the output space since most computer monitors are set to gamma 2.2; I assume the same is true of phones and tablets but have never looked into it.

Hi, Brad,

I didn't have the time to answer, but I tried this and, well, I couldn't match the footage, but the BMPCC ended up looking much better. I noticed an obvious improvement. I don't know if it's me, but thank you!

And, Shebbe,

I still have to study your post, but I will try it and let you know how it turns out!

Thanks to both.

Roberto Mata wrote:
I didn't have the time to answer, but I tried this and, well, I couldn't match the footage, but the BMPCC ended up looking much better. I noticed an obvious improvement. I don't know if it's me, but thank you!

I'm pretty much always happy with OG BMPCC footage with Resolve Color Management. But as Shebbe explained CSTs can achieve the same thing, they just require a bit more knowledge on your part as Resolve Color Management is more of an automated solution. I always try the simplest approach first, and if I'm happy with it then I can stop there unless I want to explore incremental improvements.

When you say you want to match the footage, are you talking about colors and contrast, or more than that? You'll never be able to make the iPhone footage look like it was shot on BMPCC, but you should be able to match colors and contrast. There are some good tutorials on shot matching available on youtube and other places that you can use to try to get them closer.

Yes, color, contrast, softness of the image, the warmth of the lens...
As I write this, I realize it must be impossible to match. The same lens on a different camera? Maybe. But an iPhone, no matter how good the image quality, and the pocket camera paired with a Russian lens from decades ago, doubtfully.

Anyway, I've abandoned the idea for the time being. I'll stick to my vertical 1080x1920 (and then upscale) for now.

Thanks, Brad. I'll check those YT tutorials you allude to if I ever feel tempted to try it again.