I actually have 1 question, Lets say i use 70-200 F4 and 70-200 F2.8, both in same aperture, lets say F4, use same focal length lets say 200mm, taking same subject, will the F2.8 give me nicer bokeh than the F4? I cant really test it since i only have the F4, i'm only sure that the F2.8 will be sharper at F4, but how about the DOF and bokeh?
DOF is definitely shallower as the number says it all. Bokeh wise honestly if u just look at the picture as a whole there wouldn't be much difference unless u really go and take note of all the details of the blurred background.