>>4278004i'm in a similar boat hahahahaha but the aberration isn't nearly as bad for me, yours look rekt tho. i'm using a bellows for macro photography to scan my negatives, and an md rokkor zoom lens.
could also be that the camera or the extension tube isn't correctly aligned and or not facing the negative as straight as possible cuz you're a fag? get a couple of those spirit levelers to try and align the place of the negative to the camera??