Does chromatic aberration always have the colours displaced in the same way or does it depend on the lens?

Question

I'm needing to match some 3d stuff to some 4k video, so a little chromatic aberration wouldn't be out of place. However, due to the way I've learned to do it (scale one of the colour channels), I just experiment until something looks like it fits, instead of using something accurate.

However, I'm wondering if the abberation is always constant so I can do it more accurately. Like for example, would red always give the inside lining, with cyan (absence of red) being the outside lining, then green gives a smaller (half the size) inside lining and so on, or does it entirely depend on the lens being used?

I would have thought it should be constant with the way light bends, but from looking at google images, it seems some images don't seen to follow it.

Answer 1

Chromatic aberration comes about because the index of refraction of the glass used in the lens varies with frequency. You would expect the first order effect to be linear with frequency, but of unknown sign, so you could have red inside or outside, violet outside or inside, with green in the middle. Different glasses have different variation of index with frequency. Lens designers can choose the combination of glasses to cancel out the shift. If they do very well, the second order effects can become more important than the first order effects and all bets are off.