[Tord555]

DOF is "governed" by apparent aperture size (and equivalent focal length when you are comparing different setups).

 270mm f5.6 on FF -> 100mm f2 on Nikon 1. Similar FOV and same DOF.

Apparent aperture size: 270 / 5.6 = 48mm. 100 / 2 = 50mm.

Ah, there I learned something new, again!

 

So, as I often shoot with the 70-300CX with f/5.6 @ 300mm, that equals then to an apparent aperture size of 53mm, not that bad ;-) !