Computer Science 39J

February 29, 2008

Depth of Field

-Aperture

-Focal Length – “Zoom”

-Distance from subject

-Focal Length and distance from subject correlate and cancel each other out.

-For example, you take a picture from 15 ft away. Then, you distance yourself another 20 feet from the subject and you want to achieve the same composition in the second photo as you did in the first. In order to do this, you must zoom in. Therefore, the greater the distance, the more you’ll have to zoom.

-Longer Focal Length and subject distance tends to create better bokeh in your photograph.

Magnification

-Circle of Confusion – the largest blur circle that will still be perceived by the human eye as a point when viewed at a certain distance.

-How does magnifying (increasing focal length and subject distance) effect DOF?

-DOF may help to guide the viewer to the subject of the photo

Homework: Drawing with Light

-Use lighting for artistic value

-Take a picture where your interest is more on the light than the subject, where you use light to specifically guide the viewer to a certain subject.