I've just bought a ND3 filter (-10 stops) and was looking for recommendations on how to focus the camera.
Basically many recommendations are around focusing WITHOUT the filter, then switch to manual focus, screw in the filter, set the shutter speed and take the shot. The reason is that it would be impossible to focus with the ND filter on (the viewfinder is very dark).
However, I can see that LIVE VIEW works very well with the ND filter ON. It even seems to be able to focus correctly.
So what's the drawback of using this method? I do understand that the metering might be a bit off (but this can be compensated with some trial/error on shutter speed I guess?).