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Hi, I'm new to this forum, but saw there were a few posts from A7S owners and users on here, so thought somebody may be able to help with the predicament I find myself in. I recently bought a Sony A7S, with metabones EF-E adaptor (Mark IV) and Sigma Art 24-105 lens. I'm having a lot of trouble getting the lens and camera to connect properly - Sometimes, the lens works fine and I can shoot long video clips no problem. However, a large proportion of the time, the set-up has several issues: 1. The aperture randomly jumps 1/2-1 stop either side of my current exposure. 2. The iris won't open and close when I change it in the camera. When it does, there's a 5-10 second delay until the lens catches up with the camera. 3. I have downloaded the firmware upgrade on my macbook, and when I open the app and connect the adaptor, nothing happens. I have also downloaded it on my iMac, and it won't even open, it just crashes straight away. I also tried downloading it on my girlfriends macbook, but it also won't open on there. Any help would be greatly appreciated. Thanks, Andy