F - Stops , aperture and Depth of field

Manual Techniques - F - Stops  = Depth of field

Aperture

Aperture is the size of the opening of the lens when a picture is taken.  Whe you hit the shutter release button on the camera a hole opens up that allows the image sensor to catch a glimpse of the scene you are wanting to capture.  The aperture that you set affects the size of the hole. 

The smaller the hole the less light gets in (shallow depth of field making the image in the foreground in focus and the background fuzzy).

The larger the hole more light gets in (large depth of field means most of your image is in focus wether its close to the camera or far away) .

Aperture is measured in F Stops - f/2.8, f/4, f/5.6,f/8,f/2



Aperture has a big impact upon depth of field. Large aperture (remember it’s a smaller f stop number) will decrease depth of field while small aperture (larger numbers f stop number) will give you larger depth of field.  Small numbers mean small DOF and large numbers mean large DOF.

Different styles of photography require different DOF.  For my chosen area Portrait it is better to use a large aperture (small f stop) to make the subject in complete focus and the background blurry.  Landscape photography tends to be smaller apertures (high Fstop) to allow the whole of the image from the foreground to the horizon to be in focus.

Diagram of decreasing apertures, that is, increasing f-numbers, each aperture has half the light gathering area of the previous one.

Depth of field/aperture example shots

 Large Depth of field = higher f stop number = small aperture

 Shallow depth of field = F Stop 5 = large aperture