Here I have found some railings in a church yard. With the aperture open as far as possible (f5 in this case) to give the minimum depth of field I took a picture of the railings.
I then focused on the background and retook the shot.
There is a slight movement between the two pictures as
- the camera was not tripod mounted
- to get the camera to focus on the background I had to move the focus off the railings, focus, and reposition. This is because I cannot manually focus on my camera (or if I can I have not discovered that yet).
Also the exposure was different by a couple of stops between the railings and the background. I had to compensate for this in Lightroom. In fairness none of the above issues had detracted from the images for this exercise.
The first shot demonstrates that being really close to the railings and on f5 gives a shallow depth of field. On the second the subject is further away therefore the depth of field is deeper, but it is not deep enough to have both background and foreground in focus. Between the two shots thinner branches of the trees do not show in the first as they are so out of focus they are barely perceptible.
Of the two shots I feel more comfortable with the foreground in focus. I think that this is because the way our eyes see in that they tend to focus on foreground object as a way to orientate and avoid bumping into near objects and focus to the background when needed.