dear CS-ers, recently i learned that in cropped sensor DSLR you don't get same kind of shallow DOF (with the nice bokeh we all love) like FF while using same aperture size. one guy explains that DOF is a function of sensor to object distance, and because cropped sensor camera has to be further from the object compared to FF, the DOF will not be as shallow.
can someone explain this further please? like in actual terms what's the comparison. i read somewhere f2.8 on cropped sensor will be the equivalent of f4 on FF. is that accurate?