Very nice Smudge,mine are crap;I need to get my lens recalibrated as it`s useless for contrails now.
My efforts. 
Where do you get it done?
My lens is a Sigma lens,so you have to send it back to Sigma UK and they do it free up until the lens is 3 years old-unfortunatly postage costs are pretty high,and you have to pay that yourself (around £40 with proper insurance.)