Depth of Field: Practice Shoot & Past Examples

Below are some pictures I have taken in the past that pertain to this theme:

f8, 1/60th, ISO100, 50mm.
This is a shot of my garden this afternoon (17/10/12). They say all lenses work best between f8 & f13. The former seemed perfect for this scene. Deep enough to ensure the gate is fully in focus, but not shallow enough to capture the contents of the garden itself (the slide is my landlady's 2yr old's).

f4, 1/125th, ISO100, 50mm.
This is the same image, this time shot a full two stops wider than the previous. The garden itself is becoming slightly blurred. If the weather is fine tomorrow I will shoot them at apertures a lot further apart to give a better example.

f5.6, 1/200th, ISO 200, 55mm,  flash:
One of my favourite gig photos taken in Oswestry, Shropshire. I learned from a fellow photographer  prior to my first wedding, that f5.6 is perfect for events. Here the singer is the focal point, but the bassist is also fully in view.

f5.6, 1/125, ISO, 30mm.
A shot from a wedding I assisted at. Theme of 'looking': I am observing the boy who was in the process of observing the bride & groom until I obviously got him to pose for this. The shallow depth of field helps tell this story. 

f4.5, 1/250th, ISO 200, 28mm, x4 enlargemnent filter.
Flowers from Debdale Park, Gorton; not too far from where I live. What I like about depth of field is, that without the blur of the background flower, the focal point in the foreground wouldn't appear half as sharp. Had I done this again, I would have shot another at f8 to confirm this.

f11, 1/80th, ISO 100, 44mm, x4 enlargement filter.
One from my Action Man shoot. I've experimented with my Polaroid  close-up filters here, which aim to mimic an expensive macro lens. The fact it is shot at f11 just goes to show how much depth of field is accentuated the more we zoom into the subject (or in this case, the effects of the filter). I had to completely 'stop-down' to ensure the viewer could still make out it was Action Man holding the cigarette. At a wider aperture the background was completely blurred.

Below are some past examples of wide depth of field, which were shot using a narrow aperture setting:

f13, 1/125th, ISO200, 18mm.
This is one of my landscapes shot at Debdale Park in Gorton.. I have my own rules for aperture settings: f11 for buildings, f13 for full-blown landscapes such as this in daylight.

f22, 30sec, ISO 100, 22mm.
This was shot at Liverpool's Albert Dock during dusk. I had my tripod, which allowed me to use a very long exposure. To balance this I also used a very narrow aperture for maximum sharpness. I feel the image works because of the minimal focal point and mass of expanse to the left.

f11, 1/80th, ISO 200, 18mm.
As I mentioned above, I've gotten into the habit of shooting buildings and structures at f11.

f16, 13sec, ISO 400, 36mm.
A narrow aperture and long exposure again here, this time shot at a higher ISO to accommodate the low light conditions (and make life simpler). Night time is a different beast when shooting buildings.

Below is a very brief 'shoot' I did during last week's session, whose aim was to show how the depth of field changes when reducing the aperture ('stopping-down'; larger number).

f3.5

   f4.5

f5.6

f7.1

f9

f11

This may not be the best example (I haven't chosen full-stops & only used the kit lens) but I hope it shows how more comes into focus the as the aperture is narrowed (in other words, as the number goes up).