[Leica] digital glass

["tlianza" <tlianza@sequelimaging.com>]

Hi to all,

I recently purchased the new Nikon 12-24mm lens that was designed
specifically their digital cameras.  It was a very enlightening experience,
because it demonstrated how a "blank page" design could really lead to some
excellent quality and it illustrates an endearing comittment to a lens mount
that has served them well over thirty years.... The lens offered very low
distortion for a wide angle zoom, the off axis performance is excellent with
minimal color.  As someone who has designed lenses in the past, this lens is
a technical tour de-force.  Naturally, it's profoundly retro focus, the exit
pupil is located quite a distance from the principle points so control of
coma must have been a real problem for the designers.  They seem to have
done a fine job there.  Off axis specular reflections are quite symmetrical
and vignetting is quite minimal for a lens of that focal length.  The
designer could take into account the glass in front of the sensor and that
is a real necessity for control of chromatic aberration. The lens utilizes
the newer AFS motor which allows you to simply overide the auto focus, by
manually focusing or you can simply switch it off at the lens. The combined
weight of a D100 camera and this lens is less than 3/4 the weight of my M7
with the 35 summilux.  A single battery is good for about 500 shots which
nicely fills a DVD for archiving on the go.  So, why do I keep the M series
and R series cameras?  They take great pictures (technically) and they are
very tough.  I've been working on workflow techniques to make the digital
tone reproduction mimic the film->digital workflow but there are real
challenges there.

 I ran an interesting series of tests that utilized 5 camera/film
combinations (3 leica bodies (2M, 1 R) 2 Nikon bodies, 5 different types of
film) compared to the digital output from the D100.  I then took six
different scenes.  The film images were scanned in an LS4000 scanner and
then all the digital files where printed at 12X18 inches using a fuji
frontier printer.  I then asked observers to rank-weight the images.  In 5
of the six tests, the digital camera (6 Mega pixel) was judged "better".  In
one instance, the observers generally chose an image shot with an
R6/Summilux 80 combination on a fine grain transparency film.  One of the
first observations was that whatever image quality advantage the leicas had
on the film, was lost in the scanning-printing process. It appeared that
grain noise was more objectional to the observers than resolution issues and
the sharpening utilized in the digital camera images had very little impact
on the apparent noise in the image.  Inspite of the low resolution of the
digital camera, the fact that it required only one optical step allowed for
less sharpening and lower noise recording than the film combinations. I also
suspect that the fuji frontier imaging system also contributed to the image
degredation.  So what I am seeing in my work and my tests is that the output
path (scanning-> paper) is a greater limiting factor than digital resolution
vs analog film resolution.  Examination of the film images under a loop and
higher magnifications showed that the Leica images may have a bit of an
edge, but there was no obvious difference.  That accounted for the obvious
confusion in the evaluations of the reproductions after the digital image
was removed from the test: no single camera/film combination stuck out as a
winner.  At this point in time, I feel pretty comfortable with either
digital or analog workflows.  If I'm in a situation that requires a wide
dynamic range capture, I use negative film.  If I'm shooting for saturation
and sharpness, I'll use transparency film .  If I need a decent image with
almost no hassles or in a short time period, I'll shoot with digital and I
know that at modest reproduction sizes, it will do just fine. Now I can stop
screwing around with all this testing and just go out and shoot....


Tom Lianza
Technical Director
Sequel Imaging Inc.- A GretagMacbeth Company
25 Nashua Rd.
Londonderry, NH 03053


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