Yeah you are right about the exposure more than anything, I could of explained myself better. But I do quite a bit of shallow focus landscape shots where you need to focus as accurate as possible. Let alone focusing through big stopper without taking the darn thing off between each frame.
I have been using a D800 for 1.5 years, whose Live view is said to be worse than that of the D600, and I am yet to see a single frame not perfectly focused when I use live view.
The high magnification mode of the live view on these cameras is not sexy, but it makes it very easy to find the peak of focus by looking at the way the pixelization changes as the focus is tuned.
The fact that live view uses the lens stopped down gives you 2 options:
- If you use a lens with some focus shift (probably the case of the Tokina you were trying to use), then you should directly use live view with the lens stopped down to get very good, but not excellent, focus accuracy. This can make the image pretty dark, but this focus shift is a lens issue that would bite you if you were trying to focus with the lens wide open anyway,
- If you use a lens without any focus shift, then you will get a better focussing accuracy by focusing with the lens wide opened and then stopping down afterwards.
So I still don't understand your comment, unless you are saying that it is not a good idea to use a lens showing some focus shift for dusk/dawn photography... in which case I totally agree!