Focus with a set aperture:
A scene was chosen which had depth. In this case I chose a line of champagne bottles with one odd one out! Three photos were taken from the same point each one focussed on a bottle at a different distance. The camera was set at it’s lowest f-stop number. The three images were then compared and the preferred photo noted.
I spent a bit of time selecting the right scene for this exercise and in the end selected some champagne bottles lined up. The near and middle photos I am happy with as a clear distinction is seen between where the eye is drawn. However with the far photo I suspect I am limited by the lack of distance between the near and far bottles and also the f-stop of 5.6 which in this case was not low enough to give distinctive depth of field. My preference is for the middle image.
Focus with different apertures:
A scene was selected showing a row of dry stone wall from an angle. Each photo was framed identically focussed on a mid point on the wall. The first of the three photos was taken at f5.3, the second at f13.0 and the third at f36.0.
As you can seen a wide aperture setting creates a smaller depth of field. To obtain a sharp image from the front to the back of the frame then a small aperture should be used from about f/11 upwards. In the above images a clear difference exists between the wide and narrow apertures but less so with the mid aperture.