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256
THE HASSELBLAD MANUAL
distance photography only. This is not so. The focusing distances are limited for mechanical
design reasons. All tele lenses can be used at closer distances in combination with close-up
accessories. Extension tubes are perfect for this purpose.
The close-up charts in Chapter 19 show the area coverage with different extension tubes
for focal lengths up to 255 mm (150 mm lens plus 1,7 converter) for the H system and up to
250 mm in the V system.
INTERNAL FOCUSING
Focusing a lens to closer distances usually means moving the entire lens farther from the
image plane thereby making the lens physically longer. This is still the case with many lenses.
On many modern lenses, especially telephotos, focusing is accomplished optically by mov-
ing some of the lens elements within the lens design. This method, which does not change
the physical length of the lens at all or only to a minor degree and does not result in a rotat-
ing lens barrel, is known as internal focusing. Internal focusing can result in smoother, easier
focusing than the mechanical type, especially in long telephotos. Since internal focusing does
not move the entire lens, the focusing range can be and has been extended all the way where
it can produce life-size magnifi cation on the HC 4/120 macro for the H system cameras while
maintaining the automatic focusing capability over the entire focusing range. Figure 14-18
shows how the lens elements are moved in the 120 mm HC macro lens when focusing from
infi nity to the minimum focusing distance where the lens produces life-size magnifi cation on
the fi lm format. This was partially made possible as the focusing mechanism does not need
to turn or move the entire lens. Many Hasselblad H system lenses have internal focusing indi-
cated as rear or front focusing, depending on whether the front or rear elements are used for
this purpose. The image quality of the 120 mm HC Macro lens is shown in the MTF diagrams
for different distances in Figure 14-19 (see also Figure 14-20).
H SYSTEM CF LENS ADAPTER
The CF lens adapter allows using all the Carl Zeiss lenses from the V camera system on all H
camera models for digital imaging or for fi lm photography (Figure 14-21). You can photograph
with H system lenses that you may already have and also extend the range of lenses with
those from the V system such as the 30 mm fi sh-eye or the very long 500 mm telephoto type
which are not available in the H system. The use of the adapter is indicated on the LCD screen
and shown as either "My lenses" or "All lenses." After you program the My lens setting with the
lenses that you consider using on the H camera, the lens selection is faster when you actually
use the lens. You must program the proper lens into the camera to assure that the light meter-
ing system gives the correct fi gures.
All exposure metering modes in the camera can be used and the metering is done with
the lens aperture wide open as it usually is with C type lenses. The aperture and shutter
speed settings are read on the LCD display and are manually transferred to the lens. With
CFE lenses a preset aperture is electronically transferred to the camera. All V system lenses
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