Aperture and DOF in live-view (with Pentax K-30)

About the issue

It seems that during live-view the aperture used is neither the maximum aperture the lens is capable of (like it happens while using the optical view-finder), nor the chosen aperture value (either manually in M / A or automatically in S / P / scene modes).

After a quick experimentation I came to the conclusion that it's somewhere between 4 and 5.6.


However one can easily preview the depth-of-field by using either:

Either of these features can be assigned to the RAW/Fx button.