Lensbaby effect in photoshop

I decided some years ago that actually buying a lensbaby was a waste of money, they are very good at what they do but it's quite limited and I cant justify the price for the used I'd get out of it. 
I figured it shouldn't be too difficult to mimic the effect in photoshop, I got pretty close ages ago but at the time I couldn't work out how to add enough chromatic aberration, the lens correction filter just didn't give a strong enough effect, anyway I was playing with the effect again (making an action actually) and the penny dropped, all I needed to do was move the red and green channels slightly out of register and job done.