Lloyd Chambers has reported that the a7R shutter vibration is worse when the camera is in portrait orientation. This makes sense if the camera is mounted directly to the tripod head, or if the mounting is very close to the camera, but my guess is that for long lenses with tripod collars that the effect is not as significant.
Here’s my reasoning. I have determined that the main vibration of the shutter is up and down when the camera is in the landscape orientation. Tripods are usually better at resisting up and down motion than side to side motion. You can demonstrate this to yourself by pressing on the top of the ball head and pressing on the side. Therefore, if the camera is mounted directly to the ball head, when it’s in landscape mode, the vibration will occur in the direction that the tripod is best able to resist. In portrait mode, the tripod is vibrated in its less effective direction.
With a big lens with a tripod collar, the camera/lens combination vibrates as a torsion pendulum even if the tripod is perfectly resistant to motion. There’s no a priori reason to think that this vibration has a preferred orientation, although it might.
Lots to test here, and the results would apply to many cameras. Modern focal plane shutters move up and down, not side to side, so that they travel shorter distances and can have higher flash synch speeds. That means that they will have the same preferential vibration plane as the a7R. Mirror slap is primarily up and down as well.
One thing to keep in mind when it seems like the sky is falling on the a7R: the contribution of camera shake of the a7R live view pre-exposure shutter closure is about a quarter of that of mirror slap on the D800E. The difference id that, in the D800E there are ways to separate the mirror-up operation and the shutter opening by enough time to let the vibrations from the mirror slap to die down, while there is no such mechanism availabe to the a7R owner.
That’s not saying there won’t be. I think it should be possible to introduce firmware workarounds.
One possibility would be to add a drive mode. Let’s call it Single Shot Delayed Shutter. It could be accessed by pressing the Fn key like all the other drive modes. When the camera was in that mode, it would operate similarly to a Nikon D800 when the dial on the top left of the camera is turned to the Mup position. With the camera in live view, the first press of the shutter release or trigger from a remote release would close the shutter. The display would go black. The second press would cause the shutter to open, make the exposure, close, and open again to enable live view.
The above scheme would have teh advantage that it would be familiar to people who have experience with modern Nikon and Canon DSLRs. A method that I would prefer borrows from H-series Hasselblads. In this approach, there would be an option in the set-up menus to assign one of the programmable buttons on the a7R to control the live view shutter position. The button would operate as a toggle. The normal mode would be the same as it is today. The shutter is normally open, and pressing the shutter release causes it to close, open, close, and open again to enable live view. The delayed mode, accessed by pressing the assigned button, would close the shutter and disable live view. Pressing the shutter release would cause the shutter to open and close, and it would stay closed. The finder would remain dark. Further presses of the shutter release would do the same thing. Another press of the assigned button would restore normal operation.