The firmware has been updated to the latest version as of June 28, 2025, using the official SIGMA USB Dock. Operation is perfect! The aperture blades are clean and work properly. It doesn't have any defect which affects images.
Very good lens, everything it says it does happy buyer. You really need a full sensor camera to fill it’s potential at present I have a cropped sensor so upgraded body asap.
A million leagues above my previous Sigma 70-200 f/2.8. A little bigger and weightier but well worth it- Fast and silent focusing, sharp images- Simply lovely