Week 2 Assignments

Overriding Auto Focus

1. Focus on the subject by half-pressing the shutter release.
2. Once the camera has focused - press the button (AF-L)
3.  Reframe and fully depress the shutter release.

We learnt about Depth of Field (DOF).  You can maximize or minimize DOF by controlling Aperture, Focal Length, and Focal Distance.  Maximum depth of field is required to show the details of the scene so I used a smaller aperture above - f/25.

An example of a photo with shallow depth of field control. (only the main suject of interest is enhanced by throwing other elements out of focus.

A shallow depth of field achieved using f/5.6  and below f/5..

Quick Reference Guide: Depth of field is governed by three factors: aperture, lens focal length and shooting distance. Remember the following relationships:

1. The smaller the aperture, the deeper the depth of field (the other two factors remaining the same). For example, if the lens focal length and the shooting distance stay the same, the depth of field is much deeper at f/16 than at f/1.4.
2. The shorter the lens focal length, the deeper the depth of field (the other two factors remaining the same). For example, comparing a 28mm lens with a 50mm lens at the same aperture and shooting distance, depth of field is deeper with the 28mm lens..
3. The greater the shooting distance, the deeper the depth of field. i.e. other two factors remaining the same). For example, if the subject is photographed from three and then from seven meters away, the zone of sharpness in the foreground and background is greater at seven meters.

Another characteristic of depth of field is that it is generally deeper in the background than in the foreground.