[thxbb12]

You mean like this?



(shot in JPG)

 

Not quite. More like this:

 



 

Or this:

 



 

 

Or this:

 



 

 

In all these cases, one could also use a single exposure and postprocess to obtain a somewhat similar result. However, there will be either quite a bit of noise present in the under-exposed area of the image or some blown highlight.

If the over-exposed or under-exposed area is somewhat small like in your example, it's okay. However, in my examples above, these are large areas of the image which is a different ball game.

A sensor providing much higher DR than what is currently available would allow to take a single shot and be able to obtain the same results as with ND grad filters.