In my job I work with PS retouching old book covers. In many case I work with channels and calculations (to mix channels I created).
I wanna to make the same things with AP but I can't:
In PS I do:
1) I copy a channel (example: red and rename it to "red copy").
2) I select the recently created channel, double click and can work on it in grayscale (it appears on the viewport) and I just leave a black and white version.
3) When I finish I copy another channel (example blue channel and rename it to "blue copy").
4) The same process.
5) After finishing the blue copy modifications I open the calculations dialog box.
6) I mix the "red copy" and "blue copy" and I get a new alpha channel
7) I use it to mask a zone in the original image.
How can i do the same thing with AP?
I bought the three Affinity apps and I very happy with them. I'm using the 1.7.1 version.