LEICA APO-ELMARIT-R - Manual (Page 7)

Chapter 3
Leica R-Lenses 6
Flare and secondary images are absent and specular highlights
in the blazing sun are free from halo effects.
Vignetting may be visible under critical circumstances (wide
open), but it is eliminated at f/5.6.
Distortion amounts to 1% in the comers and may be visible
when one photographs geometric figures (architectural details)
near the edges of the negative.
The high level of correction of the current 180 mm lens can be
seen in the MTF graphs. The f/2.8 aperture delivers the best
performance, it might be improved a bit at f/4, but at f/5.6 you
already see a small reduction in contrast, which is even more
pronounced at f/8.
0 5 10 15 20
Y'[mm]
0
20
40
60
80
100
[%]
2.8
5.6
8.0
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
0 5 10 15 20
Y'[mm]
0
20
40
60
80
100
[%]
Aperture Stop 2.8
1
0 5 10 15 20
Y'[mm]
0
20
40
60
80
100
[%]
Aperture Stop 5.6
0 5 10 15 20
Y'[mm]
0
20
40
60
80
100
Aperture Stop 8.0
[%]