Expand the white balance adjustment range for IR photography and RYYB sensor.

[chemharuka]

I was recently taking infrared photos, using a camera without lowpass filter & IR filter. And taking photos with RYYB sensor (Huawei Phone). 

However, Affinity Photo only provide limited white balance adjustment range in RAW files process. In Adobe Camera Raw, the adjustment range of Tint is from -150% to 150%, but only +-50% in affinity photo.

Compare affinity photo with two mobile apps:  Snapseed and Lightroom

IMG_6304.CR2 was taken by Canon 500D & 590 nm filter, with correct built-in white balance parameters. In Google's Snapseed, the tint value is -100 (minimum) but the color is a bit of red, and in Lightroom mobile the tint value is -150, also looks red. I guess the built-in tint value equal to -200% in affinity, and build-in temperature is less then 2000K.

P5300010.DNG, photo by Yi M1 M4/3 camera with 590 nm filter, without correct built-in white balance parameter. In Snapseed auto WB, the tint value is -100, and looks very good. In Lightroom I set tint to -150 and temperature to 2000 K, the photo  looks orange.

IMG_2002xxxx.dng, photo by Huawei Phones, with correct built-in white balance parameters, the build-in tint value in affinity photo is 81% and equal to +37 in Snapseed, +34 in Lightroom mobile. It's interesting that affinity recognized correct tint value, 81%, but can't adjust the value (if I do, it turns to 50%)

So, affinity can correctly display the photo with correct built-in white balance, but can't edit the white. I hope that affinity photo expand the adjustment range of white balance, to 1000 K~25,000 K in temperature and +- 200% in tint, and add picker tools in raw white balance.

IMG_6304.CR2 IMG_20200530_121127.dng

Edited May 30, 2020 by chemharuka

[chemharuka]

An error happened when uploading P5300010.DNG (-200 error), So I uploaded it to my cloud storage, this is the link:

https://haruka-1252713705.cos.ap-beijing.myqcloud.com/share/P5300010.dng

Edited May 30, 2020 by chemharuka

[cosi]

Yes, I just asked for the Huawei P30 Pro lens calibration data to be included in the lensfun database (https://github.com/lensfun/lensfun/issues/1211) and I confirm the issue with the RYYB sensor.

It starts at value of e. g. 76 for neutral white and if you try to modify, it jumps to the maximum of 50, which leaves a green tint. The white balance tool to select a reference white from the image is working though.

Screenshots are attached.