Special Features - Leica APO-ELMAR-S 1:3.5/180mm ASPH Instructions Manual

spEcIal FEaturEs

The Leica Apo-Elmar-S 180mm f/3.5 is a lens designed for the Leica S SLR system. Due to the
30 x 45 mm sensor size of the Leica S cameras it is comparable to a focal length of 144 mm
with 35mm format systems.
The Leica Apo-Elmar-S 180 mm f/3.5 has a high speed relative to the format. Even at full
stop, it demonstrates maximum contrast and resolution over the entire image field and across the
full setting range. The imaging performance is at such a high level that stopping down does
not result in any significant increase. The lens has only very slight longitudinal and mag nification
chromatic aberrations and the secondary spectrum is very well corrected – as you would
expect from the "APO" in its name. Imaging faults such as curvature of field, astigmatism and
coma are practically non-existent.
The vignetting, characteristic of any optical system, is a maximum of 1 stop, which means that
it rarely becomes evident in practical photography and can be further reduced by stopping
down. The distortion is very low at just 0.64 %/1 % (at infinity/1.5 m) and in practical terms is
only perceptible in the image with exceptionally critical subjects.
A total of 9 lenses are used to achieve this exceptional performance. To correct the chromatic
aberrations, they include six lenses made of glass types with anomalous partial dispersion,
two of them in the front group made of fluoride-like glass with exceptionally low dispersion. In
addition, highly refractive glass is used in three lenses to minimize monochromatic aberra tions.
Because focusing is carried out by moving one group of three lenses within the overall construction,
the total length of the lens remains unchanged.
summary: The Leica Apo-Elmar-S 180mm f/3.5 provides exceptional imaging perform ance
from the infinity setting to the close-up limit, at full stop and when stopped down. This pro vides
a free choice of aperture for composition, with no need to worry about any deterioration in
image quality. As the internal focusing means that the weight distribution remains constant,
this telephoto lens is also very comfortable to handle.
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