I am sending one of my lenses for calibration to Sigma. The lens is still under warranty so that will be done free of charge, but it has also managed to aquire quite a lot of particles inside of the optics, and I am just wondering, if they will clean the lens anyway while calibrating or should I specifically ask them to do this, but then I am guessing they may want to charge me for that as for an additional service, and to my knowledge, cleaning is not covered by warranty. If anybody has any expierience with that I would be grateful for sharing. Thanks
