If You've Updated Your Sigma Lens' Firmware, Check Your AF Calibration

Last week, we reported that Sigma had released firmware updates for several of its Global Vision-series lenses. The updates was designed to allow compatibility with Canon’s in-camera Lens Aberration Correction. However, it seems the updates may have had unintended consequences.

A site visitor noticed that after updating his Sigma 50mm f/1.4 Art lens' firmware to v.2.00, his lens exhibited noticeable backfocusing which required a -8 setting at various focus settings to correct via the Sigma USA Dock.

As I had yet to update my own Sigma 50mm Art's firmware, I decided to see if I replicate the issue. I tested the lens' performance on my 5D Mark III and 7D Mark II and the lens focused accurately with no AFMA value applied in-camera or in-lens (via the USB dock) with firmware v.1.00. After updating Sigma Optimization Pro to the latest version, I upgraded the Sigma 50A's firmware to v.2.00. After the upgrade, the lens required a -6 AFMA correction to be applied either in-camera or in-lens (at all focus distances) for accurate autofocusing.

Note that the Sigma 50mm Art lens' AF was advertised as being adjusted in its specific firmware release notes for "an improved focus accuracy during Live View mode."

We're interested to know whether or not the AF recalibration is necessary for all of the lenses whose firmwares were updated, or if it's only the Sigma 50mm Art that's experiencing the issue. So if you have one of the following lenses and you'd like to provide your feedback, apply the latest firmware update and let us know if your lens required recalibration for accurate AF.

• SIGMA 35mm F1.4 DG HSM | Art Canon
• SIGMA 50mm F1.4 DG HSM | Art Canon
• SIGMA 85mm F1.4 DG HSM | Art Canon
• SIGMA 135mm F1.8 DG HSM | Art Canon
• SIGMA 18-35mm F1.8 DC HSM | Art Canon
• SIGMA 24-70mm F2.8 DG OS HSM | Art Canon
• SIGMA 100-400mm F5-6.3 DG OS HSM | Contemporary Canon

Let us know how it goes in the comments.