There's also focus issues with lens adapters as you have 3 potential places for de-focus: the front lens, the back focus on the adapter, and the stock lens. When you're running and gunning, this can really slow things down. If I can have it my way, I'm going to burden my brain with as few hardware related thoughts as possible so I can focus on making effective creative decisions. I think Lens Adapters are a great solution but can also be a lot of headaches (and back aches!). Because the Pro35 bypasses the stocks lens and has such precise controls, I found it to be a lot more comfortable to operate and with less things to worry my brain about. With the Zacuto plate, shoulder pad, and handles, the rig effortlessly went from studio mode to handheld as fast as we could get it off the sticks. That was awesome. Definitely the biggest issue with this setup is the crop factor. Without a real relay lens, your 18mm is more like a 35 or a 40. That's wide but not really wide enough in a tight space or if you have to get exceedingly close to your subject. Because the Pro35 pops off as if it were just another B4 lens, going back to the stock lens was as fast and painless as a lens change. Obviously the colorimetry between the two is quite different so my workaround was to paint a scene file to match the EX3 lens as closely to the Zeiss on the Pro35 as I could. When you're super wide, you aren't really taking advantage of the depth of field characteristics anyways so I found that by matching a color chart on the stock lens to the lens adapter and taking out some detail, the match was actually quite close and changing between the two was fast a normal lens change.
Given that with a lens adapter you're usually trying to create as much depth of field as possible, maybe this rig's telephoto effect is actually an advantage? For this project it was a great solution and got me images that made me and the client very happy. Will definitely be using this package again.