Something a bit different this time with a test of the new Canon F 1.8 50 mm prime lens. To gauge its Depth Of Field or focus range I took the following shots at F 1.8, F 2.8, and F 5.6 respectively. It may not be a really scientific test but it does clearly illustrate the difference at each setting. I hope this is of interest to you.
f 1.8 at 1/1250th of a second exposure
f 2.8 at 1/ 500th
f 5.6 at 1/100th
It is interesting to note how the focus has improved more in the foreground range. Further f stop adjustment up to f 22 would improve the background or distant range too with little improvement in the foreground. To illustrate my point:-
f 22 at 1/6th
Note how the change from a large aperture at f 1.8 to the smallest aperture at f 22 has affected the shutter speed to obtain the same exposure under the same lighting conditions.