We're told by a Canon Rumors reader that Sigma has stated that production of the 24-105 f/4 DG OS ART series lens is on indefinite hold for all mounts.
Unfortunately, production of the 24-105mm has been halted in all mounts. It was originally supposed to be released for Sony this month, but now production is on an indefinite hold. I will save your e-mail address and get back to you when we know more.
Please let me know if you have any questions.
Have a great day!
Sigma Corp of America
We hope to hear why production has been put on hold in the coming hours.