ExpoImaging ExpoAperture2 Manual (Imperial/Standard) - Manual (Page 18)

ExpoAperture 2 Depth-of-Field Guide Manual
V 1.0
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Next, divide the focal length by this number, and the minimum and maximum distances
you use on the Distance Dial by the square of this number, to bring them back to within
the usable range on the Depth-of-Field Guide.
Therefore, if shooting with a 300mm focal length lens, divide the focal length by 3 and the
distances by 9.
EXAMPLE:
Using a 200mm Focal Length Lens and a Depth-of-Field of 120' to infinity, use the Depth-
of-Field Guide to determine your necessary aperture setting using a 20 micron circle-of-
confusion (1.5x factor digital sensor).
STEP 1 –
Divide the 200mm focal length of the lens you are
using by 2 and set yellow Focal Length window to
the resulting focal length. 200mm divided by 2 =
100mm.
Set the focal length on the Depth-of-Field Guide to
100mm.
STEP 2 –
Divide the distance range required by 4 (2 squared)
and find those new distances on the Distance Dial.
(120' - ∞') divided by 4 = (30' to ∞'). Find the distances
of 30' to ∞' on the Distance Dial.
STEP 3 –
Count the number of depth-of-field zones (alternating
gray and white areas) within the distance range you
found in Step 2. There is 1 distance zone (gray area)
between 30' and ∞'.
STEP 4 –
Locate the number of zones for your desired depth-of-field on the front of the Guide to
find your aperture setting. Find the number 1 on the gray zone area on the focus zone dial.
RESULT:
f/27 (halfway between f/22 and f/32) is the aperture to use to get 1 depth-of field zone.
Therefore, use f/27 with a 200mm focal length to get a depth-of-field from 120' to infinity.