Exercise: Focus at different apertures

Three elements affect how an image is made: Aperture/Shutter Speed/ISO (to be discussed in depth @ [xx])

The object of this exercise is to show how focusing at different apertures effects the sharpness of the subject matter and to illustrate the depth of field achieved. Using manual settings I took three photographs, one at the widest aperture, one at the mid-point and one at the smallest aperture. As recommended, I choose to shoot something on an angle, and decided on a row of cans. (inspired by Andy Warhol’s Campbell's Soup).

[f4 1/60 ISO 1250]

Here the sharpest point of focus is on the second tin from the back, the third and fourth cans beginning to be out of focus.  – This image exhibits depth of field.

[f9 1/40 ISO 1250]

I chose an aperture of f9 for the second image being the mid point in my lens range. Here the range of sharpness of image is spreading slightly from the second can to include some of the rear can. The front can, remains out of focus, and there is still a certain amount of depth of field

[f22 1/4 ISO 1250]

In the final shot, I used the smallest aperture f22. When the image is enlarged, you can see that most of the cans appear in focus and are sharper.

In conclusion this exercise demonstrates how, when using the widest aperture, a shallow depth of field is achieved, along with a smaller area of sharp focus. In contrast, the smallest aperture captures more of the image and increases the clarity and sharpness.