Upload & Sell: Off
Well, I got the next copy today along with another copy of the 85/1.4. This is so confusing. I pulled the 35/1.4 out and snapped a few test shots of my wife, focusing on her eye. Nothing scientific; just normal usage. Again, it seemed to be front-focusing significantly. The tip of her nose was in focus, but her eye was blurry. Snapped several shots like this and got the same result. These were taken at a close working distance, i.e. 2-3 feet.
So I thought, ah, yes, the problem is with the camera after all. To confirm I put the new 85/1.4 on and took a few test shots. Nailed focus and very sharp at f/1.4.
Is it possible that the camera could have an AF problem that shows up more with some lenses more than others? Because even with Sigma's reputation, I find it hard to believe that I have been this unlucky with their lenses. Out of 7 copies total (2x 35mm, 2x 50mm and 3x 85mm) with this camera body, only one (my most recent copy of the 85) has been good. Not to mention the fact that Roger from LensRentals has tested multiple copies of the Sigma 35 and they've all been accurate with AF.
I think at this point I'm just going to send the 5D3 in to Canon. If I don't, I will always doubt.
Not sure if I should once again return the Sigma 35, or just send it in to Sigma with my 5D3 once I get it back from Canon.