From MDI Film…
This is a very solid cage for DSLR, it is well built and it is heavy. It works well when we tested with the Canon 5D3 and 70D, and it also works great for the Gh4.
However, you can't change the battery if using smaller cameras like the Gh4 or the A7s as the cage is just 0.20mm off. Sad.
ALSO: Just discovered that if you plan to connect hdmi and headphone, the lock port will not make it easy for GH4 users. So, expect to connect audio to your headset from the HDMI external monitor instead or you will not be able to monitor audio unless using one of those right angled adapter.
We have made this as a go to shoulder rig setup just like what Tom Antos did.
For more information about the rig and Tom Antos video review, visit : http://www.came-tv.com/cametv-dslr-cage-for-gh4-sony-a7s-5d-mark-iii-p-401.html