Leica APO-ELMARIT-R, APO-TELYT-R User Manual
Leica R-Lenses
September 2003
Chapter 3: 180 mm and 280 mm lenses
__ LEICA APO-ELMARIT-R 180 mm f/2.8
__ LEICA APO-TELYT-R 280 mm f/4
by Erwin Puts
Chapter 3
Leica R-Lenses
1
Telephoto lenses have a long tradition at Leica. The first 20 cm
f/4.5 Telyt lens was introduced as long ago as 1935 for the
Leica rangefinder camera. An additional mirror reflex housing
was required for the accurate determination of the field of view
and the focus. This 200 mm lens was designed for landscape
work, animal photography and sports photography. It is interesting to read that sports photography in modern large stadiums
was only possible at longer distances, and this required the
long lengths. The lens was also quite suitable for portrait studies, the classical head-and-shoulders type.
The Telyt was three times as expensive as the standard 50 mm
f/3.5 Elmar lens, and with the mirror reflex housing it was five
times as expensive.
The design was a true telephoto design: the total length was
about 0.8x the focal length. A long focus lens is simply a lens
with a longer focus than a standard lens (more than 2x). Examples: 90 mm Elmar, 105 mm Elmar, 135 mm Elmar lenses.
There are also lenses with a telescopic construction:
example: 800 mm f/6.3 Telyt-S. This type of lenses has been in
use since 1700. The very first telephoto lens was introduced in
1891 by the English firm of Dallmeyer. By now this design is 112
years old, and it was only recently upgraded to a very high optical performance, not in the least by the efforts of Leitz.
The first 180 mm f/2.8 Elmarit-R lens for the Leica R-System
was introduced in 1967 as a counterpoint to the 180 mm f/2.8
Zeiss Sonnar lens that was introduced in 1966 for the Zeiss
Contarex system. With five elements in four groups, it was a
state-of-the art design, but the Elmarit lens weighed 300 grams
(10.6 ounces) more than the Sonnar lens. The price-ratio to the
standard lens was now 2:1. The second version (of 1980) weighed only 750 grams (26.5 ounces) and it had a somewhat better performance. Gradually, 180mm lenses were beginning to
be used for hand held dynamic photography when a tripod
would be a hindrance in following rapid movements of the subjects.
The Achilles heels with telephoto lenses are the chromatic
errors and the size of the secondary spectrum or chromatic difference (typically 0.002 times the focal length [F]).
Visible light is composed of wavelengths with frequencies from
short waves of about 380 nm (nanometers) to long waves of
about 780 nm. Lenses are generally corrected for two specific
wavelengths: 643 nm (red) and 479 nm (blue), so that both
these wavelengths will focus on the same image plane.
This plane is located behind the plane where the third important wavelength (green, 546 nm) is focused. The longitudinal
difference between these two locations is called the chromatic
difference. If only two wavelengths are focused in the same
plane, all the others will focus somewhere else on the optical
axis. The sum of these aberrations is called the secondary
spectrum. 'Secondary' may also be read as 'residual chromatic
errors'.
A 180 mm telephoto lens has a magnification factor of 3.6x
compared to the standard lens and this means that the residual
chromatic errors will also be enlarged 3.6 times. At the start of
the seventies it became clear that the performance of these
long focus lenses lagged behind that of wide-angle and normal
lenses and therefore needed improvement. New glass types
with high refractive indices and anomalous (non-linear) dispersion were needed.
Light waves are refracted by different amounts depending on
their wavelengths. The power of the lens depends on the wavelength. This is called dispersion. Normally the power will increase continuously with decreasing wavelength. If the power changes abruptly, this is not normal or non-linear or anomalous.
New glasses with these characteristics were developed in the
former Leitz glass laboratory and later produced by Schott,
Corning and others. By means of an appropriate optical design,
the secondary spectrum could be reduced to so small an
amount that for all intents and purposes an image free of color
defects could be created. This state of correction is known as
apochromatic correction.
Erwin Puts
Leica Camera AG
Chapter 3
Leica R-Lenses
2
In 1975 Leitz Canada designers computed the 180 mm f/3.4
Apo-Telyt-R lens for scientific purposes that required a very
high information content. It is a seven-element system with four
groups, corrected for the infrared region and it performs best at
infinity. At the same time Canon introduced a new 300 mm
f/2.8 lens with synthetically grown fluorite crystals, a solution
that Leitz did not wish to use.
With the 180 mm f/3.4 Apo-Telyt-R, Leitz offered a high performance lens that undoubtedly inspired a friendly competition
with other prominent companies. Reduction of the weight of
lenses was the primary concern and goal as such lenses grew
in popularity for hand-held photography in available light. Subsequently, new lenses were introduced: in 1977 (180 mm f/4
Elmar-R) and in 1980 a new computation was made for the 180
mm f/2.8 lens.
For a short period there was a choice of three 180mm lenses
(f/4, f/3.4 and f/2.8) that were close in price: in relation to the
standard 50 mm f/2 Summicron-R lens the ratio was: 2.4:1,
2.9:1 and 3:1.
The second version of the 180 mm f/2.8 Elmarit-R lens could
not outperform the 180 mm f/3.4 Apo-Telyt-R lens. And the
shortest focusing distance of 2.5 meters (8.2 feet) was unre-
markable. In addition, the ergonomics were no longer state-ofthe-art as more and more companies introduced internal focusing.
In 1998 Leica introduced the new 180 mm f/2.8 Apo-Elmarit-R,
a system that can be described as "Return of the Empire".
The price ratio to the 50 mm Summicron now became 3.5:1,
just as it was in the thirties.
A lens with the focal length of 280 mm for the Visoflex system
was introduced in 1961, and in 1970 a 250 mm lens was introduced for the Leica R-system.
Both versions offered commendable but not top performances.
The same challenge of optimal weight, high performance and
short near focusing distance existed here as it did with the 180
mm focal length, and the first computations by leitz were not
entirely convincing.
This changed abruptly with the introduction in 1984 of the 280
mm f/2.8 Apo-Elmarit-R, an outstandingly good performer with
internal focusing and a weight of almost three kilograms (6.6
pounds). These characteristics required the use of a tripod and
they restricted the lens to static photography. With a price ratio
of 10.6:1, it was not a lens for the normal Leica user.
__ LEICA APO-ELMARIT-R 180 mm f/2.8
Chapter 3
Leica R-Lenses
3
In 1993 the 280 mm f/4 Apo-Telyt-R was introduced. Performance was improved, especially in the outer zones; the weight
was reduced to 1875 grams (66.1 ounces) and the price ratio of
4.8:1 was much better.
In terms of performance, both new lenses, the 180 mm f/2.8
Apo-Elmarit-R and the 280 mm f/4 Apo-Telyt-R, are world-class
lenses and they represent the finest examples of the outstanding excellence of the current quality of optical design at Leica
Camera AG.
__ Artistic considerations
Both lenses share essentially the same characteristics, but the
strongest visual effects can clearly be seen with the 280 mm
lens. Pictures with these lenses show the classical compressed
image: two cars in a row look as if they collided and many cars
acquire a new wedge shape. Pictures of groups of people look
like the paintings of people by Rembrandt.
We can explain this with a small experiment:
Let us photograph two objects of the same size that are located
one meter (3.28 feet) from each other at a distance from one
meter (3.28 feet) from the first object.
The second object is then twice as far away from the lens as
the first object. Therefore the second object will be seen and
reproduced at half the viewing angle of the first object.
It will be halved in linear size.
Now we move the camera to a distance of three meters (9.8
feet) from the first object. Now the viewing angle of the second
object is 3/4 of that of the first object.
The linear magnification is thus 3/4 of that of the first object.
Our brain assumes that large objects are always close to us.
As the second object has 'grown' from 1/2 to 3/4 the size of
the first object, we assume that it must now be closer to that
object.
This effect explains why telephoto lenses produce a compressed or foreshortened perspective.
__ LEICA APO-TELYT-R 280 mm f/4
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