Hasselblad Digital Camera, Manual

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Close-Up Photography on Film or Digital
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Determining the Length of the Extension Tube
The easiest way to determine the necessary length of the extension for a specifi c lens and
magnifi cation is from the Close-up Charts A and B at the end of the chapter. The charts for the
H camera system show all the information for the lenses from 35–150 mm and the 50–110
zoom lens and for fi lm and for the different sensor sizes. The HC Macro 120 mm is not included
because it does not need extension tubes for higher magnifi cations. The V system charts are
for the 80 to 250 mm lenses recommended for close-up photography but only for the fi lm
format. You will need to recalculate them for the smaller sensors as described under Using the
V system Charts for Digital Imaging at the end of this chapter
Exposure
Correct exposure in close-up photography is obtained in the same way as at longer distances.
When using a handheld exposure meter, make certain that the meter reading is based on the
small area to be photographed. Taking the reading of the graycard held over the subject is
often a good approach with refl ected exposure meters. A metering system built into the cam-
era or prism viewfi nder offers a defi nite advantage because you can see exactly the area that
is measured by the meter. You may still want to use a graycard in diffi cult subject situations.
A metering system built into a camera or prism viewfi nder also eliminates the need for con-
sidering the increase in exposure. This is necessary when you move a lens away from the image
plane which is done with extension tubes. Whatever the built-in meter says should be correct
because the light is measured through the lens and extension tube. The close-up charts for the
V system lenses show the necessary increase needed for handheld meters. The H system charts
also show this adjustment although the built-in meter is undoubtedly used for this purpose.
OTHER CLOSE-UP ACCESSORIES
Teleconverters for Close-Up Photography
Because teleconverters increase the focal length of a lens while maintaining their minimum
focusing distance, they can be used to cover smaller areas without the need to move closer
to the subject. The Makro-Planar 120 mm lens, which covers an area about 8 inches (200 mm)
wide at the minimum focusing distance, can cover an area as small as 4 in. (100 mm) wide
when combined with a 2
teleconverter. The HC 2.8/80 mm in the H system covers an area
11 14 inches (27 36 cm) at the minimum distance. Combined with the H1.7 telecon-
verter the lens covers an area as small as 6¼ 8¼ in. (16 21 cm).
A lens/teleconverter combination can also be combined with extension tubes. The tube
or tubes are attached to the camera, and the lens/teleconverter combination is attached to
the front of the tube or tubes. On the H camera and the HC lenses, image quality is slightly
improved when the tube or tubes are mounted between teleconverter and lens. The
teleconverter is now attached to the camera, the tube or tubes are attached to the converter,
and the lens goes in front of the tubes. This arrangement also provides a somewhat higher
magnifi cation but may produce a somewhat higher light falloff at very high magnifi cations.