Help for white balancing

[Edoardo radice]

Hi all, this is my very first post on Affinity Forum and I have very little experience with Affinity Photo.

I'm an astrophotographer and today I'ma trying to postprocess a Moon image to create a "mineral moon" image.
I usually use an astrophotograpy dedicated software but now I want to try to process the image with Affinity.

The very first step of mineral moon processing is perfectly white balancing the moon disk by aligning the RGB hystograms.
In my case, as you can see in the attached picture (Image 01), the moon has a strong yellowish/pinkish color (due to some preprocessing I have done before) so I've tried to white balance.
First I tried to use Filters-Color-Automatic white balance, but the result isn't good. (Image 02)

Second I've tried with a color balancing layer, using the picker and tracing a rectangle on the moon surface with the ALT button pressed.
Even in this case the color balance isn't correct: I still have a red excess (as you can see in the histogram) (Image 03)

Only moving the sliders by hand I can get a decent result (Image 04 and image 05 after saturation), but I would prefer a more "automatic" method.

Am I doing something wrong?

Just for reference I've uploaded the result that I've obtained with the astrophotograpy software (where I have a lot of esperience).
Thank you for help

Edoardo Luca Radice

[smadell]

I was watching a YouTube tutorial by PixImperfect where he answers the question about how to remove a color cast in Photoshop. (His tutorials are ALL based on Photoshop, but a lot of them can easily be translated to Affinity Photo.) Unfortunately, the video relies on using the Divide blend mode, which Affinity Photo does not yet offer (why???). Fortunately, a little bit of poking around on these forums got me a really good answer as to how this can be done in Affinity Photo, simulating the use of the Divide blend mode. Here are the steps:

1)  Using your original photo, select a color that should be white (or as close to white as you can get - i.e., a very, very light gray). In your photo, I used the Color Picker to click on the spot that I've indicated with the arrow. This loads that color into the "primary" well of the color picker.

2)  Create a new pixel layer. From the Edit menu, choose "Fill with Primary Color."

3) Invert the layer, and set the Blend Mode to "Color Dodge." This should remove your color cast nicely.

So, it's not completely automatic. But it's a good start.

In fact, I made you a little macro that automates the very few steps involved. NOTE - the macro assumes that you've already chosen the spot that should be white, using the Color Picker tool, and that the color is active in the primary well of the color picker.

Also note that this is a single macro, NOT a macros category. As such, you have to import it into the MACRO panel, not the Library panel.

Color Cast Removal Layer.afmacro

[Edoardo radice]

Hi thank you for your reply: the workaround is really smart and it works fine.

But do you agree with me that Affinity white balancing of my image is really strange?

I expect that the area selected with the W.B. picker turns grey, not reddish.

In your opinion should I open a post in the bug section of the forum?

Thank you again

 

Edoardo

[Old Bruce]

I used one of your screenshots, the first one, and a White Balance adjustment layer to get an approximate level. These are the settings...

[lepr]

10 hours ago, Edoardo radice said:

Hi thank you for your reply: the workaround is really smart and it works fine.

But do you agree with me that Affinity white balancing of my image is really strange?

I expect that the area selected with the W.B. picker turns grey, not reddish.

Yes, the White Balance Adjustment picker is dysfunctional in Affinity apps: the top slider does not become well positioned and the bottom slider never moves.

The equivalent tool in the Develop Persona when processing a camera raw file was significantly improved quite recently and is now good, but it is still useless in Develop Persona when processing an Affinity Pixel layer.

11 hours ago, Edoardo radice said:

should I open a post in the bug section of the forum?

You could, but Serif have been made aware of the problem for over four years. Some bugs become trapped near the bottom of a prioritised list of required fixes in software produced by any development company, not only Serif.

 

[Edoardo radice]

Thank you for your kind reply.

But we are speaking of a White balance bug!!! imho it is a major bug in an image processing software considering that in other software (even free ones) works as expected.
 

Even if well known (I haven't found the post you cited: I was only looking for 1.8 verion bugs) I'll try to open a bug report.
Thank you again

Edoardo
 

 

[lepr]

35 minutes ago, Edoardo radice said:

Thank you for your kind reply.

But we are speaking of a White balance bug!!!

I'm fully aware that this is a bug. I wrote "Some bugs become trapped near the bottom of a prioritised list of required fixes" in my post, and the ancient post to which I linked is a bug report.