Sony DCR-TRV900 Operating Instructions Manual page 56

Using the PROGRAM AE function
About the depth of field
The depth of field is the in-focus range, measured from the distance behind a subject to the
distance in front. The depth of field can vary with the iris (F value) and the focal length.
Lowering the F value (large iris) reduces the depth of field. Raising the F value (small iris)
provides a larger depth of field. Zooming in telephoto position offers a smaller depth of field
while the depth of field in wide-angle position is greater.
The depth of field
Iris
Zoom
56
Shallow
Open (Low F value)
Telephoto (T)
Deep
Close (High F value)
Wide (W)