Schneider
Lenses for Large Format Photography.
What
digital lenses are best with the new large format scanning
back cameras? Schneider or Rodenstock?
When
you switch from traditional photography to large-format digital
photography (this means using a Better Light, Dicomed, or
PhaseOne class of high-end 4x5 scanning back) what new equipment
will you need? Yes, your old studio lights and your traditional
lenses will still work, but digital lighting and digital lenses
will be noticeably better.
Today's
CCD scanning backs are so sophisticated that the lenses can
see the non-overlapping red, blue, and green planes of focus
in normal lenses. With traditional film, no normal 120, 220
(medium format) or even 4x5 picture would be capable of noticing
these imperfections in older lenses. The better APO lenses
would have already solved some of these problems.
You
can see the lack of concurrent focus very easily. Just take
a digital picture of any linear grid (such as graph paper)
or even simple lined note paper. Enlarge the image on your
computer monitor. You will see that instead of one black line
you have three lines, one is red, another blue, another green...
This
means that if you enlarge your photograph (such as on wide
format printers) you are reaching the realm of color fringes.
Same thing with lighting, some lights (such as one model of
Dedolights) may cause banding due to electrical interference.
All this came as an unpleasant surprise to lighting and lens
manufacturers. Many reacted in a defensive manner saying their
products were perfectly okay. But quietly, one after the other,
they are producing new models that come closer to being in
synch with the needs of the new digital era.
Actually,
lighting and lens manufacturers should be happy about all
of this, since it means they have thousands of new customers.
The Better Light digital camera, for example, is considered
so good that it is selling almost faster than Michael Collette's
crew can assemble them. Every happy new owner of a new Better
Light scanning back will need digital lenses and possibly
digital lighting (I review digital lighting on www.digital-photography.org
and www.cameras-scanners-flaar.org).
At
the international Photokina trade show in Cologne I spoke
with several representatives of Schneider and I met with a
pleasant and knowledgeable manager of Rodenstock in Munich.
Both Schneider and Rodenstock make the medium format and large
format lenses with German optical know-how which have never
been equalled by anything from any other country.
If
you do not have a budget for a new lens or if you don't enlarge
to the point where you see the RGB banding, then at least
try to utilize apochromatic lenses. For normal digital photography
I use my older Schneider and Rodenstock lenses and my eyes
do not notice any difference. But if you intend to drape an
entire building with your large format creation, you might
wish to investigate the new digital lenses.
If
you use a macro lens for product photography, we get best
results from the 180 mm Macro lenses. If I remember correctly
the 180mm Macro from Rodenstock is an APO lens whereas that
from Schneider is not. Do not use a wider lens for macro;
it will elongate (distort) your image. I found this out when
I evaluated a 120 mm digital lens from Schneider. This lens
elongated the subject even when directly in front of the object
with no lens tilting or other movement.
The
Schneider digital lenses are marketed under the series designation
Digital. shneideroptics.com (in USA), the German web site
is wwwSchneiderKreuznach.com.
For
more information on what lighting you need with large format
digital
cameras check out www.digital-photography.org
and www.cameras-scanners-flaar.org
|
|
|
|
|
|
|
All reports by Dr. Nicholas Hellmuth
|
UPDATED:
August 02/2001
|
