Use a combination of small apertures and wide lens to take a number of photographs exploring deep depth of field.
For this exercise, I used a tripod and a 2 second shutter release delay to avoid camera shake. A prime lens was used – Fujinon xf18mm f2. My main interest was to understand whether there was an optimal aperture for the lens achieving a great depth of field – for many lenses, I understand that the edges of the frame can loose clarity at extreme apertures.
Below is a contact sheet, including the lens settings. The f/9 and f/10 are included for comparison purposes. It is not so easy to compare the differences in the shots with the images at this size, but at full size there are some clear differences:
b) f/11 is sharp to the end of the wall.
c) f/13 to the end of the garden (fence), but not the first tree on the right-hand side.
d) f/14 extends the sharpness to the two trees.
e) f/16 extends the sharpness far into the distance, but details are so fine at this distance it is not clear whether this adds an advantage. A clear disadvantage is that the image is beginning to loose clarity at the edge of the frame.
The conclusion is here that a fully closed down aperture is not necessarily the optimum setting for maximising DOF with this lens, and I would guess the same applies to many ‘consumer’ grade lenses.
I will repeat this exercise, for my own benefit for my two fixed lens cameras – one a fixed prime and the other a fixed zoom.