Trying to Create a "Chromatic Aberration" Brush

[avespanthera]

hello!

i’m relatively new to Krita, trying to get used to it after using Paint Tool SAI/SAI2 for probably over a decade now. currently, i’m trying to get my brushes in order, and i saw a brush tutorial that caught my eye but so far haven’t been able to get the demonstrated effect to work.

this is the tutorial, which shows a brush that looks to have a chromatic aberration effect. when i tried to follow it, the brush i made had barely any black in the strokes and just looked like three colors with a little bit of black in the middle.

i tried a different approach as well, using a basic (solid black) brush tip shape and displacing CMYK colored copies of it around the shape, but it got pretty much the same result (or worse).

does anyone here know where i might’ve gone wrong, or know how to actually get the effect shown in the tutorial?

here’s what it looked like when i tried it:

(this was done quickly with a mouse, but using my stylus with full pen pressure and such didn’t make a difference)

[Takiro]

Not visible in your screenshot unfortunately so I assume you forgot to set the blending mode to either Multiply or Darken, the last step the Tutorial mentioned.

[avespanthera]

while i forgot about that for the screenshot, i did set it to multiply, which didn’t change the result. i’ll try darken when i gwt the time and report back, though.

[Takiro]

Also turn off Rotation. And there are a lot of other options enabled (like texture) you probably don’t want. What brush did you use as a base? Better use something like Basic Round brush as base because it doesn’t have many options enabled by default that could interfere with your brush, especially if you’re new to brush making.

[avespanthera]

ah, good point! i’ll give that a try when i get home later (currently on my way to work).

thanks!

[avespanthera]

alright, finally back from work and able to try this. i used one of the most basic brushes as a base this time.

unfortunately, the result is pretty much the same. setting the blending mode to darken didn’t change anything either.

[Takiro]

I wonder if it’s because the brush tip is set to colored image, it will always use the exact image and not use the blending modes at all but I’m not sure. Perhaps you can share the brush tips for us to try ourselves.

[avespanthera]

sure, here’s a quick/messy version i grabbed straight from the tutorial image just for testing.

(let me know if the file is good or if i should upload it elsewhere and provide a link)

i’ll mess around a bit more with it myself as well.

[KNap]

I think I see the problem. We want the black on the brush tip to multiply or darken the colored parts of it so it’s always visible, but it’s not the order it works with. The brush stroke we make interacts as “normal” blending mode with itself and then multiplies/darken with whatever else was on the layer.

[avespanthera]

ooohh, interesting. is there a way to get it to do as you said?

as a side note, i messed around a bit more and noted that it does seem to be using the multiply mode even when set to color image, as crossing strokes over each other when it’s set to multiply causes the colors to mix/change where they cross (cyan on top of yellow changes to green, for example).

[KNap]

I think I just found it! There’s a “Painting Mode” option in the brush settings. I changed it from “Wash” to “Build Up”.

And now it looks like this:

I also tried to make it more black by modifying the brush tip like this:

…and the effect is looks this:

Perhaps something between those two would look better.

[avespanthera]

yesss, that worked! thank you!!

i’ll play around with the amount of black on it and such to get it to where i like it. i appreciate the help!

[KNap]

I used the “multiply” blending mode in those examples, but it seems “darken” works better. Multiply turns cyan into blue and yellow into greenish (which makes sense since they multiply with themselves) while darken keeps the original colors, at least until they cross with each other.

You’re welcome, I’m glad I could help.

[avespanthera]

very happy with the results i was able to get, thank you all!