Whitebalance issues in C1?

Hi,

I was doing some testing the other day with some video, and wanted to set the WB correctly in camera. I shot a RAW image of my WB reference card with my camera in the same light at the same spot, where I was going to film. First I used Luminar 4 to measure the Kelvin. The WB picker reads approx. 6K Kelvin. The C1 WB picker reads 7811Kelvin !?!? Apple Photos reads 7200Kelvin, Lightroom reads 6000, Dark Table reads 5969 Kelvin. That's quite a huge gab between 6K in Adobe, Skylum and Dark Table and almost 8K in C1! I initially contacted Skylum support, because I obvious believed that C1 was giving me the right data, and L4 was reading something way off. After some investigation, it seems that C1 is the software that reads the Kelvin in very different way than other software (according to Skylum support), and reads some very high values. C1 reads from 800-14000 Kelvin where as Adobe "and most others" reads from 2000-25000 Kelvin according to Skylum support.

The light that was used is LED light that is supposed to be approx. 6500 Kelvin according to the manufacturer specs.

I made a folder on Dropbox with a screenshot of all the readings and the RAW file with the white balance reference card: https://www.dropbox.com/sh/arwwviefgey6suu/AABBnQcJutpPME6zX1erSD4La?dl=0

Isn't that strange?

Thanks,
Thomas

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March 03, 2021 08:05

nothing unusual, there is no standard. this are just ( fictional) numbers and do not correlate with either the camera settings or measured color temperature. you have to use custom wb with your camera to get it right.

Permanently deleted user

March 03, 2021 08:58

CSP,

Nothing unusual? 🤔 I'm confused. If I got a lightsource that's X Kelvin, and I know, that in fact the light source is that specific Kelvin degree, I should be able to set my WB in my camera to that exact value, and get a 100% neutral grey color balance (no color shift). Sometimes you do not have the luxury of having a reference image with a WB card. In that case, it's very convenient to able to just plot in the right Kelvin number, and get the colors you want, if you know the light source color temperature.

Thanks.

March 03, 2021 09:34

sure in an ideal world this would be the case but in reality it is not. it starts with how WB is calculated, different brands can have different methods giving different result. some converter are closer to real numbers as dxo for example others are not. guess the developers do no see a real need to give scientific accurate number as most user do not have a instrument to measure color temperature anyway.

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