Hasselblad Digital Camera, Manual

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258
THE HASSELBLAD MANUAL
CHARACTERISTICS AND USE OF TELECONVERTERS
Teleconverters, also called tele extenders, are optical components that are mounted between
the camera and lens to increase the focal length of the lens used in front of them. A 2
converter doubles the focal length of the lens so a 250 mm lens becomes a 500 mm type.
A 1.4
converter increases the focal length 1.4 times, so the focal length of a 100 mm lens is
increased to 140 mm. The 1.7 converter, for the H system (shown in Figure 14-22) changes
the 150 mm focal length to 255 mm. The XE designation in the V system converters means that
it has the electronic Databus connection for the metering system in 200 cameras. The XE con-
verters shown in Figure 14-23 can be used on other V system camera models. Teleconverters
provide you with a longer focal length without ending up with a much larger and heavier
lens. You can have a 360 mm focal length with a lens/converter combination that is only about
Figure 14-19
Macro lens quality
.
The quality of the HC Macro 4/120 mm lens is shown in MTF
diagrams with the lens set at infi nity (bottom) and at a distance where it produces a 1:2
magnifi cation (top). Both are shown at
f /4 and f /8.
f/4
100
80
60
MTF (%)
40
20
0
0 10 20
Image height (mm)
30
1:2
100
80
60
MTF (%)
40
20
0
0 10 20
Image height (mm)
30
f/8
f/4
100
80
60
MTF (%)
40
20
0
0 10 20
Image height (mm)
30
100
80
60
MTF (%)
40
20
0
0 10 20
Image height (mm)
30
f/8
Infinity