Resolution of FRR Function
To see down to a resoution of 1nS, you would need 1/f = t or 1GHz scope.

The scope you has a bandwidth of 70MHz or 1/f = t or 14.2ns



If you really want to see 2ns (500Mhz) then you'll need double or a 1GHz scope to really see what is going on. Impedance and inductance will become an issue with measurement rise times, so make sure you use proper technique when making this kind of measurement. 

For more info see this