[davidmanze]

  My test for decentering is super simple, distant views at infinity focus at full aperture at all focal lengths, it's the test that emulates real life photos, if it passes distant trees test it's good.. Any decentering will show up straight away and distant trees are one the hardest tests of resolution. Yes, I've battled away returning lenses and won, although it was at a price of being patient with service departments waiting for spares. I've had so many decentered lenses I'd say I have returned 75% of them, " What sort of industry is this for god's sake?"