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8/13/2019 Making Full Use of Interchangeable Lenses
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Motonari Sasaki, Video Technology Analyst, Up Side
Making full use of interchangeable lensesStill Lenses and Cinema Lenses
Photo 1: The Panasonic AG-AF100 series allows a vast range of lenses to be used via the mount adapter.
To enable a photographer to create exactly the video
they have in mind, the photographer has to consider
a wide variety of elements, including the camera’s
performance. The imaging power of the lenses is one of
the crucial elements.
The previous generation of small camera
recorders suffered from small sensor sizes and non-
interchangeable lenses, so images naturally had a deep
depth of field. Photographers overcame this problem
by attaching still lenses or PL mount lenses with DOF
adapters to the small camera recorder lenses. Examples
of these solutions included the Letus35 from Letus and
the Mini35 PL from P+S Technik. These arrangements
enabled photographers to achieve unique video results
and shallow depth of field that fixed lenses could not
provide.
Later, between 2005 and 2009, camera recorders
such as the Canon XL H1S (1/3type) and the Sony
PMW-EX3 (1/2 type) made their debut. Though the
sensors were still small, these camera recorders offered
interchangeable lenses, as well as adapters for easy
changing of lens mounts. By choosing the right lens for
each shoot, photographers were able to significantly
expand the expressive range of their small camera
recorders.
Today, with the rich array of digital SLRs now on offer,
large image sensors are routinely installed in compact
bodies, making it easy to achieve a shallow depth of
field. The major lens manufacturers are busily producing
lenses that support digital SLR mounts; for example, Carl
Zeiss makes set lenses for the Canon EF and Nikon F
mounts.
Panasonic introduced the AG-AF100 series. Launched
in December 2010, the AG-AF100 series is the industry’s
first camera recorder to incorporate the Micro Four Thirds
system, which was designed for mirror-less digital SLRs.
The sensor size is 3/4 type, and lenses for the Micro Four
Thirds mount are now offered by all major companies,
including Panasonic (the lineup of lenses is fuller
than that for the E Mount, which is based on a similar
concept). Furthermore, a key feature of the Micro Four
Thirds system is the use of a short flange back, which
enables a huge variety of lenses to be applied through a
mount adapter (Photo 1).
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Photo 2: A wide range of mount adapters
are sold for the Micro Four Thirds mount,
including the PL, B4, Leica Screw, M42,
Nikon G and Canon EF.
Photo 3: Triad PL: The Micro Four Thirds mount adapteris fitted with a flange-back adjustment mechanism.
Photo 4: The Jupiter-12 35 mm F2.8 lens with Leica screw mount
has a protruding rear element that interferes with the sensor, so it
cannot be mounted on the AG-AF100 series.
Mount Adapters
The conversion adapters for the Micro Four Thirds mount
are available, including the PL, B4, Leica Screw, M42,
Nikon G and Canon EF. With the right combination of these
adapters, virtually any lens can be mounted on the AG-AF100
series (Photo 2).
The PL l ineup o f mount adapters i s par t i cu lar ly
comprehensive. The range in types of adapters is stunning,
including ange-back adjustable types designed for factor-freeuse and xed mount adapters mounted with 15 mm diameter
rods to serve double duty as lens supports (Photo 3).
The lens adapters for the Canon EF series incorporate a
built-in iris mechanism, enabling them to restrict the aperture
just before the light reaches the camera through the lens.
However, if the selection of mount adapters is varied, the
lenses available is far more so. Be aware that some lenses
have long rear elements that prevent them from being used
with mount adapters (Photo 4).
Notes on Combining with Still Lenses
The AG-AF100 series can be mounted with a wide varietyof still lenses, giving video photographers a whole new
dimension in exibility.
■Zoom lenses
In video photography, complete flange-back adjustment
capability is a highly desirable feature for zoom lenses.
However, still camera lenses are not built with zooming for
video effects in mind, but instead to focus on and capture a
single image. As a result, still zoom lenses often cause out-
of-focus problems in video shooting, depending on the focal
distance of the still zoom lens.
Moreover, the zoom rings of still lenses do not deliver the
smooth, steady movement demanded in the zoom rings of
video and cinema lenses, as this feature is less critical in
still photography. In some cases, the direction of rotation is
opposite to that which video photographers expect.
For example, the zoom ring on the Canon EF zoom lens is
the same as that on zoom lenses for camera recorders with
the B4 mount. When holding the camera (pointing it toward
the subject), this ring is turned clockwise to move to the wide-
angle end. In contrast, the zoom rings on the Lumix G Vario
series and Sony E mount lens go to the telephoto end when
rotated clockwise. Shooters accustomed to using video lensesare bound to be confused.
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Advantages of Still Camera Lenses
Still camera lenses are compact and lightweight, yet they
deliver excellent imaging performance. Adding these lenses
to your tool box will allow you to move around nimbly if the
job requires.
The weaknesses of classic lenses are exposed at the
open end of the iris, but image quality can be improved
dramatically by adjusting the iris one step. A weakness in
the eyes of one photographer may be an appealing quirk to
another. Some effects are out of reach for video lenses andcinema lenses with a PL mount, such as scenes that are
extremely blurred or darkened on the periphery only. These
images shoot on purpose can be interesting for your toolkit.
Naturally, still camera lenses suffer many more problems
than camera recorder lenses do when used in video
photography. But many are inexpensive, offer great imaging
performance, and are easy to use. By combining these
lenses with the AG-AF100 series, you can adjust your
settings menu to overcome the weaknesses of still lens and
capture better quality images.
Cinema Lenses and Accessories
Like video lenses, cinema lenses are lenses designed for
video recording, so the movement of the zoom and focus
rings won’t pose any problems. You can handle them with
none of the confusion that can arise when using still camera
lenses. Of course, the iris ring rotates smoothly instead of
clicking through stages.
Cinema lenses offer crisp, sharp images for a gentle look,
with shallow depth of eld that lends depth and richness to
images. Cinema-lens users nd that these lenses effectively
translate their photographic intentions into the results they
were looking for.
On the other hand, PL mount zoom lenses are bulky
and heavy, so they are normally used with a lens support.
For this reason, a rod-mounting support system has to be
fitted on the bottom of the AG-AF100 series. As a result,
the camera becomes heavier, and the center of gravity is
heavily skewed to the front of the camera (Photo 6).
The rotation of the focus on PL mount zoom lenses is
over 180°, so follow focus is more or less essential, and
attachment of a matte box for filter work is necessary.
With so many attachments, it’s difcult to keep the camera
balanced with a tripod head alone, so shooters have tocompensate by using a slide base, attaching a battery to the
back for balance, and so forth.
When a cinema lens is used, even if the AG-AF100 series
itself is light, the system as a whole becomes heavy, making
handheld video capture difcult. Consider adding a grip or
other items to compensate.
Support systems for the AG-AF100 seires are available
from a wide variety of manufacturers, and equipment rental
companies carry original products as well. Be sure to fit
these systems correctly to prevent damage to the camera
mount and avoid shifting the optical axis.
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Photo 6: Combination of the AG-AF100 series with the Cooke Cine Varotal 25–250 mm T4 PL mount zoom lens. The weight is severely
skewed forward; even with the slide base to improve the balance, the system hardly seems stable.