Depth of Field

As part of the introduction to aperture, we were asked to demonstrate our understanding of how aperture effects the depth of field.
Below is a simple set of images I took to demonstrate this (please click on the image to view it in full size. Note the long shutter speeds, Im hard line on using the lowest ISO setting possible, as a result I was forced to use exposure times of upto 4 seconds!)

This image was taken to illustrate how using a very large aperture (in this case f/1.4) will give a very shallow depth of field. This effectively draws attention directly to the subject. As you can see, the background is blurred, giving the subject a very prominent and sharp stance in the image.







The image below, taken from the summit of Snowdon by my self,  shows how a large aperture can allow a wide range of objects to be in focus.
If we break the image down into 4 parts, the rocks closest to the foreground(1), the mountain behind that with the sun shining on it(2), then the mountain behind that(3) and finally the mountains right at the back of the image(4).
The first 2 parts of the image are both in very clear and sharp focus, as we move back to part 3 and 4, the focus begins to soften slights, while still giving a good amount of detail in the image. This gives the viewer a sense of distance and scale, while keeping the image sharp enough to be detailed.

Below I have taken two photographs to demonstrate my understanding of selective focus. Both were taken at F/1.8

Below you can see how the foreground object is completely blurred while the background is in focus.

this time, the background is blurred and the foreground object is in focus