Quote Originally Posted by Sheiky View Post
Any idea what that EMD(Electro Magnetic Diaphragm) is by the way? I couldn't figure out precisely how that is different than normal.
I don't know how it works in a lens. In other devices, such a fuel injector, a coil which produce a magnetic field capable to move a small part. Maybe in this lens an electromagnet is uses instead a gear.

Speaking about blades an non-understanding, I've never understand why the number of blades are so important to bokeh. If you want the less DOF, you must select the widest aperture. And almost all the lenses that I've seen has a perfect circle when they are wide open because blades are completely retracted.