bellows extension
= reproduction ratio x focal length
= (2-0.5) x 82
= approx. 123
In other words, you get 2X magnification when
the bellows is extended to approx. 123mm.
• To calculate reproduction ratio with the bellows
extension value read off the scale on the bellows,
divide the lens focal length by the extension value
and add the reproduction ratio of the lens. For
example, if the bellows extension is 165mm:
o
2
+
0.5 = approx. 2.5
In other
words, approx.
2.5X
magnification
(1:1/2.5 reproduction ratio) is achieved when the
bellows is extended to 165mm.
For duplication work
More precise accuracy is required for duplication
work than for general close-up photography. For
maximum benefits from the Close-Range Correction
System, the lens should be focused at as close a dis-
tance as possible. For a reproduction ratio higher
than 1:2, the PK-11A, PK-12, PK-13 and PN-11 rings
are available. Make the extension as short as possible.
For example, to get a reproduction ratio of 1:1.6,
you can use the PN-11 (with 52.5mm thickness),
PK-12 (with 14mm thickness) and PK-13 (with
27.5mm
thickness) rings. For the most precise
accuracy, use the PK-12 ring and then adjust the
focusing ring.
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