Sigma SD9 User Manual download pdf (Page 61)

DEPTH-OF-FIELD PREVIEW BUTTON

Normally, the lens’ aperture is always fully opened, except at the time the

picture is actually taken, for looking through the viewfinder under maximum

brightness conditions.

However, by pressing the depth-of-field preview

button, the aperture can be closed down to the

selected shooting aperture before the picture is

taken, enabling you to check depth of field

through the viewfinder before shooting.

DEPTH OF FIELD

When you set the focus for a particular subject, there is an area in front of and

behind your subject, which will also be in focus. This is called the

Depth-of-Field.

Depth of Field will increase when

Using a smaller aperture value (Larger F-number)

i.e. When you photograph the subject under the same conditions but change the

aperture value from F8 to F22, F22 will show more area in focus (more depth of field).

Using shorter focal length (wide-angle) lens.

i.e. When you photograph the subject under the same conditions, changing only focal

length from 50mm to 28mm, the 28mm lens will show more area in focus (more depth

of field).

Photographing the subject at greater distance

When you photograph the subject with same focal length lens and aperture value but

change the camera-to-subject distance, the subject at the greater distance shows

more area in focus (more depth of field) compared to subject at the shorter distance.

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 115 116

No comments

Sigma SD9 User Manual Page 61