Anyone else with this combination please chime in...
I get razor sharp results before the picture is taken looking in either the viewfinder or Live View. Then, when the picture is actually taken wide open, at 1.4, the image is completely blurred. There is NO vibration - using a Really Right Stuff pod with BH-55 head, and cable release. I am NOT locking up the mirror, as I should not have to with this setup.
The exposures are 1/4000 at f1.4.
If I start stopping down, then 4-5 full stops later, sharpness starts to return in the final snapped exposure. But I consider this not only unusual, but quite ridiculous. The 5DSr performs perfectly with other lenses. I bought this lens to use wide-open at 1.4!!!
A tech rep at Zeiss has asked me if I have locked-up the mirror - my reaction is why would I have to do this at 1/4000 second?
How would I lockup the mirror if I were to hand-hold and shoot a head-shot at 1.4? I don't get it.
Obviously this does not make sense. If it is in focus in live view, the image should be in focus.
Why don't you experiment with mirror lock-up, that will at least give you some ammo with the manufacturer.
It sounds like the lens is going slightly out of focus during the shot, which is solved at f4.5 because of the increased depth of field.
Are you in manual focus? Is the image in focus after the shot?
And quick shutter speeds might not help when you have mirror slap. the camera is moving quickly, so 1/4000 might not be quick enough to freeze it, After all, the mirror is moving *fast*.