242 THE HASSELBLAD MANUAL
Figure 14-6 Illumination. Illumination diagrams for the HC 50–110 mm zoom lens at 50 mm (top
left), at 80 mm (top right), and at 110 mm (center).
at the 50, 80, and 110 mm focal length. Figure 14-6 shows the illumination at different focal
length settings.
Image Quality at Different Lens Apertures
Every lens in the Hasselblad line produces excellent image sharpness when used at the maxi-
mum lens aperture. Image sharpness, however, further improves especially in the corners as
the aperture is stopped down with maximum corner-to-corner sharpness usually when the
aperture is two or three f stops below the maximum. The MTF diagrams for all Hasselblad
lenses show the performance at maximum aperture and with the aperture closed down,
f/3.5
f/8
1.0
0.8
0.6
0.4
0.2
0
01020
Image height (mm)
30
Relative illumination
HC50–110 @ 50
f/4.5
f/8
1.0
0.8
0.6
0.4
0.2
0
01020
Image height (mm)
30
Relative illumination
HC50–110 @ 80
f/4.5
f/8
1.0
0.8
0.6
0.4
0.2
0
01020
Image height (mm)
30
Relative illumination
HC50–110 @ 110