Around two years ago, when I decided to purchase a DSLR (after owning a Kodak digital camera for 10 years), I read material related to photography using DSLR, primarily because a DSLR is a different beast as compared to a high-zoom point and shoot (AKA bridge camera). While my Kodak had APSM functionality, I never explored it, except for those few odd shots, which probably will be less than 50 in a span of 10 years.
One of the points that stuck in my mind was the usage of f/8 as the aperture priority setting. This has become by ‘go to’ aperture setting and I have ended up using it for most of my shots.
Even today, I am puzzled when photographers use an f/2.8 for portraits as I wonder how sharp the image will be. It goes without saying that I need to put together an experiment (with the same scene) and shoot it as various apertures. Only then will I understand the difference made by the aperture as well as the DoF for each aperture setting. Obviously, I will need to use an object with depth and cannot use a ‘flat’ object.