inch) lens that is focused on an object 10 feet from the
camera lens using f/2.8? (Note: In a previous example
the hyperfocal distance for the lens was found to be 554
determined as follows:
lens that is focused on an object at 10 feet, using f/2.8.
focused on an object at 10 feet, using f/2.8.
Consequently, the depth of field in this problem equals
the near distance subtracted from the far distance
(10.2 - 9.8 = 0.4-foot depth of field). Thus all objects
between 9.8 and 10.2 feet are in acceptably sharp focus.
When this depth of field is not great enough to cover the
subject, select a smaller f/stop, find the new hyperfocal
distance, and apply the formula again.
focus distance to set the lens at so depth of field is placed
most effectively. There is a formula to use to solve this
lens focus distance at 10 feet.
and lenses have depth of field indicators that show the
approximate depth of field at various distances and lens
apertures. Figure 1-30 shows that with the lens set at f/8
and focused at about 12 feet, subjects from about 9 feet
to about 20 feet are in acceptably sharp focus. By
bringing the distance focused upon to a position
opposite the index mark, you can read the depth of field
for various lens openings.
length only. There is no universal depth-of-field scale
that works for all lenses.
When the lens is focused on infinity, the hyperfocal
distance is the nearest point in sharp focus, and there is
no limit for the far point.
points, when the image is in focus, are termed conjugate
Basic Photography Course