ZEISS HOLOGON
Zeiss Hologon 15mm f/8 on Leica M4-P
Modern lens design techniques have
presented us with a relatively large number of super wide angle lenses of 15,
13 and even 12mm focal length. All of
them are very complicated, multi element designs in order to avoid visible
distortion and lack of sharpness due to under corrected optical
aberrations. These lenses have become
actually quite common, and few photographers even remember the super wide lens
which started it all.
For many years, 21 and 20mm lenses
were the maximum 35mm photography had to offer.
Anything with a wider angle of coverage had to be of a fish eye design
with all the draw backs of pronounced barrel distortion. All of this was changed with the introduction
of the Zeiss Hologon 15mm f/8 in the early 1970s. This was unusual in many respects. Not only was the Hologon the first lens to
achieve the unheard of angle of coverage of 110° without the usual fish eye
effect, it was also the first post-war marriage between Leica cameras and Zeiss
lenses.
Cross section of the three lens elements and the lens position inside the Zeizz Hologon camera body
Note the extreme proximity of the rear lens element to the film plane
The Hologon was initially developed
for the Zeiss Hologon camera, which was part of the Zeiss Contarex system. At the time it was thought impractical to
offer the Hologon as an interchangeable lens, even with mirror lock up in the
reflex Contarex. Instead, Zeiss opted
for a separate camera body, based on the Contarex with the mirror box removed
and with the lens permanently installed.
It was their claim that extremely precise registration and centering was
necessary for the lens to perform satisfactorily.
The Leica M cameras also met these
criteria and the lens was made available in the Leica M mount also. It was sold with a special 15mm viewfinder
included. The 15mm Hologon with its
undistorted 110° diagonal angle of view is one of the most interesting lens
designs in recent years. Conventional
lens design theories would indicate that a lens with such specifications would
have to be of a multi-element design.
Computer aided research of wide angle lenses for aerial photography was
conducted. The normal concept of using
many thin elements in wide angle lenses was actually revealed as
unnecessary. In fact, only three thick
elements proved necessary to assure good performance of the lens. Subsequently, the Hologon is of a triplet
design, although bizarrely shaped. Thus
we have an example of an optical design which would not have been created by
using conventional methods. Furthermore,
it is safe to say that manual computations for this design would have literally
taken years to complete.
Construction of the lens made the
installation of a diaphragm virtually impossible without compromising overall
performance. It was also impossible to
offer a speed faster than f/8 for the same reasons, even though some of the
modern optical glasses available today might offer the possibility to increase
the speed of the Hologon.
It was felt that the restriction of a
fixed aperture of f/8 would not pose any great disadvantage. Besides, a graduated neutral density filter,
offering perfectly even illumination across the entire image area, would
effectively render a speed equivalent of f/16.
This could also be used in situations where the standard f/8 aperture
would lead to overexposure.
Since the Hologon lens renders
virtually distortion free images, the camera should be used perfectly level, to
avoid excessively converging lines on verticals. For that reason the 15mm viewfinder had a
built-in spirit level, which helped the photographer keep the camera level,
especially when shooting hand held.
The ability of an extremely wide
angle lens to render virtually distortion free images allow the photographer to
shoot many photographs where it is impossible to tell that an extremely wide
angle lens was used. But this is only
one of the advantages of such a lens.
The other is that it produces photographs with a rather different
perspective. It is important to pay
special attention to the foreground since the extreme angle of coverage will
show a considerable amount of foreground when the camera is held level, even
when used horizontally. It is also
important to hold a camera with such a lens very carefully. It is quite easy for the lens to pick up ones
knuckles.
The Hologon was designed to render
optimum performance at f/8 across the entire image area. Due to the optical glasses available at the
time of its design, the lens did not quite show the high contrast level
typically associated with the high quality optics from Zeiss. In practical terms, this will result in
perfectly sharp enlargement up to 8x10 inches.
Bigger enlargements might show a certain lack of crispness when
inspected very closely. Projection of
transparencies, on the other hand, will show no adverse effects, because the
projected images usually are not inspected very close up. The same is true with big enlargements when
viewed from a more “normal” viewing distance.
The Hologon allowed focusing from 8
inches to infinity. Considering the
great depth of field rendered by such a short focal length, one might initially
think focusing to be superfluous. But
it was proven that the overall performance of the Hologon could be improved if
the lens was focused properly.
Minneapolis IDS Center
15mm Hologon
15mm field of view
Please note: The 15mm field of view images in this article are not separately taken photographs, they were cropped form the original Hologon negatives to present the view of a 50mm lens
Newer, more sophisticated lens
designs have improved the speed of super wide angle lenses and even allow for
reflex viewing. Subsequently, the
Hologon has long been discontinued. But
it deserves credit for having been the first of the super wides, and its
unusual design will always give it a special place in the history of lenses for
35mm cameras. Those who own a Hologon
can consider themselves lucky indeed.
Minneapolis Lumber Exchange Building
15mm Hologon
50mm field of view
Minneapolis IDS Center Crystal Court
15mm Hologon
50mm field of view
Minneapolis Lumber Exchange Building
15mm Hologon
50mm field of view
Not that it matters, but I am curious, what Leica M camera did you use the lens on?
ReplyDeleteNo Leica M, I used a Zeiss Hologon camera for these shots.
ReplyDeleteWhy? We are talking about a ZEISS lens here. What difference does it make what camera it is used on?
DeleteI should add that the Zeiss Contarex was one of the very few cameras from other manufacturers that was made to the same extremely tight tolerances as the Leica. That includes the Zeiss Hologon. Subsequently there is no difference if the Hologon lens is used on a Zeiss or Leica camera body.
What other manufacturers did apply the same tolerances?
DeleteTo my knowledge, the only other cameras that were made to the same tight tolerances as Leitz/Leica and Zeiss were the Alpa cameras made in Switzerland.
Delete
ReplyDeleteAn example of the M mount 15mm Hologon is currently offered on eBay for $19,300 complete with viewfinder and graduated filter.